4x4 front axle help

RebelKid1822 · Post by **RebelKid1822** » Tue Sep 13, 2011 4:09 pm

i have a 2003 zr5. the transfer case ingauges, front driveshaft spins, but the front wheels dont lock and spin. any tips of where to start?

roadrunner · Post by **roadrunner** » Tue Sep 13, 2011 5:20 pm

Start by checking the actuator and it's cable. It is located under the battery tray. Screws have been known to come loose that hold the vacuum pod to it's bracket as well as the diaphragm failing. Make sure the cable that runs from that pod down to the front axle is free and WELL LUBED. Do not use wd40 as it attracts moisture and aggravates the problem. Use CRC or walmart spray lube or other similar sprays or marvel mystery oil if it's available. If that's okay then you need to check that the vacuum lines from there to the switch on the transfer case (on top of the unit) and up to the vacuum supply are okay, hooked up, and not broken, leaking, or full of fluid from the transfer case. If they do contain fluid then a new switch and cleaning out the vacuum system is in immediate order as this will lead to other possibly more serious and expensive repairs. It's a good idea to check that switch periodically for leakage anyway as a preventive measure.

RebelKid1822 · Post by **RebelKid1822** » Thu Sep 15, 2011 6:09 pm

today i checked the acutator under the battery. it appeared to move back and forth and reset just fine. i traced the lines back to the switch finding no holes. i removed the lines from the switch and they were dry. i bought a new vaccuum switch tonite and will install it tomoro, im hoping this will be a simple fix.

roadrunner · Post by **roadrunner** » Thu Sep 15, 2011 6:49 pm

If the vacuum pod is moving okay it unlikely the switch on the transfer case is bad as that supplies the vacuum needed to make the pod move. Look very closely at that pod to make sure it does not have loose screws where it mounts to its bracket and it retracts fully. Mine did this and it was difficult to see. It takes surprisingly little play there to prevent engagement of the front differential. If that's okay check for a broken or unhooked actuator cable from there to the front differential. If all is okay there it is possible you have internal damage to the front differential. To verify operation engage the 4wd button and make sure you move the truck a few feet to allow engagement of the front end. Then put the truck in park and set the park brake with the engine still running. Jack up one front wheel and see if you can turn it easily. If it will not turn the front differential is engaged. Remember a "4 wheel drive" without a locking differential in either end is actually only a 2 wheel drive (1 front and 1 rear wheel can be stopped while it's mate on the same axle can spin). By using this method the park of the transmission and the other wheel on front being on the ground with the brake set (for safety) will act as an anchor to prevent you turning the wheel that's in the air. Hope this helps you.

RebelKid1822 · Post by **RebelKid1822** » Thu Sep 15, 2011 6:56 pm

when i checked the pod i had the battery removed and simply moved it back and forth by hand, was this the correct way to do it? and the cable is unbroken.

roadrunner · Post by **roadrunner** » Thu Sep 15, 2011 6:58 pm

No! You must verify the vacuum system pulls it on and releases it!

RebelKid1822 · Post by **RebelKid1822** » Thu Sep 15, 2011 7:06 pm

how would i do that, help plz

roadrunner · Post by **roadrunner** » Thu Sep 15, 2011 7:11 pm

It is rather difficult to see the pod with the battery in place but it is possible. If you have to pop the grille out and you should be able to see it from the front of the truck. On my 01 I can see the pod from the proper angle with a light from the engine compartment side of the front header. With the truck running in park and brake set check the pod visually it should not be sucked in in 2wd and when you push the 4wd button and it lights up the pod should be retracted to engage the front end. See my earlier post for instructions to verify operation of the axle.

RebelKid1822 · Post by **RebelKid1822** » Thu Sep 15, 2011 7:15 pm

so as long as the pod sucks in, the actuator switch on the transfer case is working, and i have a good vaccuum. and in theroy the cable should be moving and engaing the front axle. howerever if it doz not suck in, then i either do not have a good vaccuum or the pod itself is bad, correct?

roadrunner · Post by **roadrunner** » Thu Sep 15, 2011 7:18 pm

Correct! If it sucks in then all is okay as long as the pod mounts are not loose. Then proceed to the check of the engagement of the front differential I explained above.

RebelKid1822 · Post by **RebelKid1822** » Thu Sep 15, 2011 7:22 pm

ok thank you. i will try these things tomorow and let you know how it goes.

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:01 pm

ok i pulled the front headlight, and was able to see the pod. when 4x4 switch hit, the pod did not suck in. i then replaced the vaccuum switch on the transfer case, the pod still did not suck in, i am checking the line but cant find a break, is there a way to test the pod? or should i replace it next?

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:07 pm

i unmounted the pod from the frame, left the cable hooked up, the pod only will retract by hand maybe a half inch, i am assuming that it should move farther then that. when i removed the cable from the pod, the pod will fully close, and i found no air leaks in it, i can only move the cable by hand aybe a quarter inch, is this indicating that the cable may be bad?

Post by **HenryJ** » Sat Sep 17, 2011 2:20 pm

Maybe, and maybe not. The front axle needs to be rotating to be able to shift. It will not engage if the truck is not moving. The two piece shaft needs to rotate to align the shift collar. You will probably need a helper and the trucks right front tire off the ground to manually test the engagement.

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:24 pm

i sucked on the pod with my mouth and it colapsed. it appears to be working fine, im attempting to get the cable to free up and move more..

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:25 pm

i took the truck for a short drive each time to certify that the front axle had enough time to engauge.

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:25 pm

should i be able to move the cable by hand? and if so how far?

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:32 pm

i have the cable unhocked from the pod, im going to see if the pod sucks itself in, if it dose, that will rule out any doubts on the vaccuum system

Post by **HenryJ** » Sat Sep 17, 2011 2:35 pm

Spray some lubricant down the cable. Corrosion and stuck cables are quite common.
Lifting that right front wheel and rotating it while pulling the cable, will be the only way to know for sure if it moving enough to engage fully. You will feel it shift and slide the collar over the splines.

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:37 pm

when i just started the truck, i hit the 4 hi button, and the pod (with cable removed) did not suck in, do i need to be moving the truck in order for the pod to suck in?

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:43 pm

i lifted the front right tire, and with vise grips on the cable, i was able to feel the frotn axle lock, thank you for that tip. i guess im looking at a vaccuum problem, idk were to head next

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 2:46 pm

i kno that the one vaccuum line goes to the pod, where do the other two go to?

Post by **HenryJ** » Sat Sep 17, 2011 2:48 pm

The vacuum switch on the transfercase sends vacuum to the actuator. This is a mechanical switch and requires the encoder motor to shift the transfercase into 4x4 to activate that switch.
That switch has three lines. One to the actuator, one to the vacuum supply and a vent tube that runs up along the transmission fill tube usually.
Verify vacuum to the switch and proper operation of that switch. If your transfer case shifts, the switch should get activated.

Pictures in this thread

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 3:11 pm

when you say transfer case switch, you mean that the front drive shaft should spin? cuz it dose. i hooked everything back up, went for a drive, came back, left the truck running and in four wheel drive, lifted the right ront tire, and it spins freely by hand...

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 3:14 pm

the line that follows the filler tube of the trany is the one that goes to the pod, how do i check for proper vaccuu to the switch on the transfer case?

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 3:16 pm

ok and there is a vent line attached to the filler tube

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 4:03 pm

i followed the third line to the drivers side fender wall, i belive this is the pod where vaccum is drawn from?

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 4:17 pm

i looked for breaks in the lines agian, and verified that i had the plug on the correct ports on the transfer case vaccum switch...

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 4:25 pm

the line that goes to the front fender breaks off and goes to a "valve" on the intake, that valve has another line coming fromt the top of it that goes in to valve cover of the drivers side head, im assume this is where the vaccum orignates? and could it be that the valve of the intake is stuck and not allowing vaccum to the tranfer case switch?

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 4:46 pm

i found a guy online that simply took the cable that goes to the front axle, clamped it to a new cable that had a locking handle, and ran it into the cab. i was woundering what anyone had to say with that idea, id rather fix the vaccum, but idk where to head. with the cable idea, idk if i would be able to enguage the 4x4 on the go. another thought i had, are there outer locking hubs that i could get for my zr5? help plz!

Post by **HenryJ** » Sat Sep 17, 2011 4:57 pm

The right front axle and tube can be replaced with a Bravada one piece shaft. That has been done and eliminates the front axle disconnect.
There is a cable shift kit called the PosiLoc. A hack of that is what your friend is suggesting. It sounds easy, but may be tougher than you think. It takes some effort to get the front to engage. Doing that and driving can be a task.
Even if you use a manually shifted cable, or one piece axle, you still need to engage the transfercase. The next step is to change that to a manually shifted transfercase. As you can see the snowball keeps rolling downhill and gets bigger as you go.

Personally, I like the convenience of the stock system.

Patience. Take your time and keep picking through the pieces to find your problem. You have the cable working. You say the actuator is working. If you connect it to a known good vacuum source does it work?
You are doing fine so far. You will solve your problem.

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 5:07 pm

ok. as for the vacuum sorce, am i looking at thr right area of where if comes from? by which i mean the valve on the drivers side intake? that sae line branches off and goes into the drivers fenderwall. where else could i hook this line to draw a vacuum from the engine?

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 5:13 pm

i think i ay just start replacing the vacuum lines, just to be sure there arnt a leak i cant find. can anyone tell me what the size of the line is so that i will be able to get more?

Post by **HenryJ** » Sat Sep 17, 2011 5:26 pm

RebelKid1822 wrote:ok. as for the vacuum sorce, am i looking at thr right area of where if comes from? by which i mean the valve on the drivers side intake? that sae line branches off and goes into the drivers fenderwall.

Yes. Any vacuum source will work.

RebelKid1822 wrote:i think i ay just start replacing the vacuum lines, just to be sure there arnt a leak i cant find. can anyone tell me what the size of the line is so that i will be able to get more?

Don't create a bigger problem by hooking up the lines wrong. It is pretty easy to plug one end of the line and apply suction to the other to test the line. If it dry and rotting, then replace the line. Cut an inch off the line to be replaced and take it with you for size.

Find out where the vacuum quits. I would hate for you to change all the lines only to find out the encoder motor is bad , a switch is bad or the transfercase module needed to be reset.

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 5:35 pm

what is the encoder motor? and how do i reset the transfer case module?
the ines look good, except by the drviers fender, its all cracked there. i will just replace that sall section tomoro

Post by **HenryJ** » Sat Sep 17, 2011 5:52 pm

RebelKid1822 wrote:... except by the drviers fender, its all cracked there. i will just replace that sall section tomoro

Bingo. There is your problem. Dry rotted lines behind the brake booster have been the problem for more than one. It is very common.
Your HVAC should also start working properly after the leak is fixed.

4x4 Different Problems!!!!!!
4x4 none
I HAVE A LITTLE PROBLEM...

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 6:04 pm

thanks for that. ill let you kno what happens

RebelKid1822 · Post by **RebelKid1822** » Sat Sep 17, 2011 6:47 pm

just went to autozone, got sum vac line. replaced the cracked section next to the drivers fender. still no 4x4....

RebelKid1822 · Post by **RebelKid1822** » Sun Sep 18, 2011 2:56 pm

in regaurds to the vent line that is attatched to the trans filler tube, when the vaccum is activated, does the little cap on the end suck shut? or is it suposed to remain open?

Post by **HenryJ** » Sun Sep 18, 2011 3:08 pm

Open. It vents the vacuum to the actuator when the switch disengages allowing the spring to release the cable.

RebelKid1822 · Post by **RebelKid1822** » Sun Sep 18, 2011 3:11 pm

ok, well guess ill keep searching lol

RebelKid1822 · Post by **RebelKid1822** » Sun Sep 18, 2011 7:08 pm

in theory, to check vacuum at the transfer case switch, would i simply remove the the hose connecter from the switch and just hold my hand against it to see if it sucks? and if this is the rite way to do it, i should feel suction on only one line, the one from the intake, and if i had good vacuu there, i could rehook the three hose plug, then remove the line from the pod, start the engine, hit the 4x4 high, and see if i had suction to the pod correct?

RebelKid1822 · Post by **RebelKid1822** » Sun Sep 18, 2011 7:15 pm

and if i need to use a vacuum guage, wat should it read?

Post by **HenryJ** » Mon Sep 19, 2011 4:47 am

Another idea:

Woodman wrote:Hi HenryJ,
First of all I want to thank you and this forum for your help, if I had not found this forum I would not have 4wd this winter.
All it was was the spring clip was bad. After I took the cable out of the actuator I noticed that the undercut in the end of the cable was burred up, like the cable was sliding back and forth over the spring clip, so I filed the burr off the clip and put it back together. Everything works fine now.
I am going to order a new cable Monday.
Thanks again, Jim

RebelKid1822 · Post by **RebelKid1822** » Mon Sep 19, 2011 7:16 pm

thanks, i had kept that spring in mind, being as it was rusted. ive gotten a little further with my vacuum problem. i started at the intake, there was a little check vavle by my brake lines. attached to this valve was a line to the intake where the vacuum originates, a line to the resivoir in the drivers fender, and a final line that runs to the transfercase switch. i had a good strong vacuum coming into the valve, however i had no vacuum coming out of it, even if i hit the 4x4 switch. i removed the valve and it appeard to function properly, allowing flow only one way. im not really sure what the purpose of this check valve is. i removed the valve and inserted a three way connector to replace it. i now hav a strong vacuum on the line heading towards the transfer case switch.
i hit the 4x4 switch agian, and with the passenger headlight removed, i could see the pod retracting. however it did not seem to move very far. i went for a drive and parkd the truck running, still the pod did not seem very far in. i had another person hit the switch a few times while i watched the pod. it moved, but when it started to pull the cable it stopped, tried driving agian, stopped and the pod hadnt moved. i then unconnected the line going to the pod. there was a vacuum there, however it was nowhere near as strong as it was by the intake. i could barely feel it. i do not kno if this is how it should work? or if i need to start looking for a vac leak between the where the check valve was, to the t case back to the pod. im also going to try lubing up the cable more- should i be able to move it with just my fingers or is a tool like plyers enough if i just pull lightly. i moved it with visegrips the other day, had to pull it a little to get it move. im almost there i just kno it! lol

killian96ss · Post by **killian96ss** » Tue Sep 20, 2011 7:18 am

When I had my CC I had to have the dash switch replaced once and the encoder motor replaced twice because my 4wd would not engage. I believe the vacuum check valves are there to prevent moisture and other contaminants from getting through. You can usually find them for cheap in the "Help" section at most parts stores. The vacuum system only engages the front differential, and if the vacuum pod is moving the front might be engaging like it supposed to. If the front axle is engaged you should not be able to turn the front driveshaft by hand with both front wheels on the ground. If you can turn it, you still have problems in that system. If you find that everything is working ok with the front axle engagement, then it must be the encoder motor which engages the transfer case, or possibly the switch. There should be some info on this site to help determine transfer case codes if you need to go that route.

Steve

RebelKid1822 · Post by **RebelKid1822** » Tue Sep 20, 2011 8:43 am

driveshaft spins, i have locked the front end by hand, i just am not getting enought movement on the pod. found a cracked y pipe today, not sure if that is related to my vac problem

roadrunner · Post by **roadrunner** » Tue Sep 20, 2011 3:10 pm

Doubtful. More chasing of vacuum leaks sounds to be in order and you should need no more than finger pressure to contract the pod and activate the cable. Much more than that and your cable is rusty/binding and needs additional attention.

RebelKid1822 · Post by **RebelKid1822** » Tue Sep 20, 2011 6:18 pm

gotcha, so with the pod and cable hooked together, and the right side tire in the air, i should be able to lock the hub by hand. i will test it and see what happens

okaussie · Post by **okaussie** » Tue Oct 04, 2011 12:15 pm

My problem is a little bit different. My HVAC controls fade away upon acceleration due to loss of vacuum. Then it starts working again once the vacuum is reestablished from the engine.

I think my 4x4 works intermittently due to a bad hose from the "T" fitting by the reservoir and the transfer case switch. Thinking this has a leak in it and not allowing for a sealed system from the transfer case switch to the intake manifold. Thereby causing not enough vacuum to run the 4x4 and the HVAC controls.

This is how I came to that conclusion:

I disconnected the hose from the "T" fitting to the transfer case switch and capped the fitting off, thereby rendering everything in the 4x4 inoperable. Drove the CC and allowing the vacuum to drop to see if the reservoir would pick up the slack in vacuum to run the HVAC contols. It did like it was suppose to.

Then I hooked the hose to the transfer case back up. Problem reappeared. Don't hear anything like a leak, but I do lose enough vacuum for me to notice a difference in the HVAC controls. This was done in 2Hi.

Put it in 4Hi and 4lo and got the same results. I probably don't have enough vacuum to engage the front axle either due to this problem. Will do some more checking on that.

I think what I will do next is run a hose from the "T" fitting straight to the 4wd actuator bypassing the hose and the transfer case switch. This will narrow down the area to the hose to the transfer case switch and the switch itself.

If that works, then I will hookup the test hose to the switch and verify that the switch is good. It had been changed out last year when I had the tranny rebuilt. That would leave me the hose from the "T" fitting to the transfer case as the culprit.

Based on what I have done so far, I am leaning towards replacing the hose, but my problem is, is finding the route it takes and how to replace it on the connector on the transfer case. I tried replacing it once before and it seems it is tie wrapped somewhere and I can't pull the new one through. Also, I know where the switch is located but I can't see it, feel it, or able to remove the hose connector.

Mine is a 2002 strictly stock. Am I going to be able to do this or do I need to take it in??

Bill

roadrunner · Post by **roadrunner** » Tue Oct 04, 2011 2:40 pm

You should be able to get to and service all the parts mentioned in your post without taking to a shop. Some are not much fun such as the T-case vacuum switch. It's high up on the T-case and not much fun to get to. I am having a vacuum loss problem on acceleration too but have not had time to check it out yet. I do have a suggestion though. with the truck running and in 4hi (move it around a bit to make sure it engages) check to see if vacuum is venting from the T-case system at the hose that runs up the trans dipstick tube. If vacuum is present there under these conditions it is possible your T-case switch has failed or is contaminated with dirt or other debris thus venting off vacuum needed for the system and adding to your vacuum loss problem elsewhere.

okaussie · Post by **okaussie** » Tue Oct 04, 2011 9:21 pm

If that is the case why would it act up in 2Hi? When I checked it earlier, I had the vacuum loss in all positions. Then when I unhooked the hose and capped the "T" off, the problem went away..

That's why I am going to try to bypass the switch all together. As I have said in earlier posts, the switch was replaced March of 2010 when I had the tranny rebuilt and don't suspect it at this time. The hose to it on the other hand has not. That is why I suspect it. No HVAC loss on acceleration with the hose disconnected and loss when it is connected and in 2Hi.

Not a big problem now, but when the first snow or ice falls, I will need it for sure with the way these okies drive here..

Bill

BTW, will I need to remove the transfer case shield to get at that switch?? Mine has the factory shield..

Post by **HenryJ** » Wed Oct 05, 2011 6:22 am

Maybe as he mentioned the switch is bad and it is bleeding vacuum all the time? Check the vent line. It should only have a slight vacuum when disengaging and that will stop when the action is complete.
Don't fall in to the "new parts are good parts" trap. Consider everything suspect.

RebelKid1822 · Post by **RebelKid1822** » Wed Oct 05, 2011 8:07 am

the hose route is easy to see with the truck jacked up a little, a simple way to replace it with the same route is to tie a string to one end before pulling it out. then tie the string to the new hose to reverse the process. the route on my zr5 is the hose from the T by the intake runs behind the engine up agianst the fire wall to the passenger side of the engine. this is where the vent line that is next to the trans dip stick, and the line that goes to the pod are grouped together. the three lines then run over kinda diagonally to the drivers side to the transfercase switch.

okaussie · Post by **okaussie** » Wed Oct 05, 2011 9:06 am

I have taken a cutoff bolt and put it in both ends of the hose, old and new. Tried to pull the old hose to thread the new hose in the same path. no go. Like the hose is tie wrapped or something to the point of not allowing the hose to move.

I am thinking about running a new hose another route, removing it from the transfer case switch and either leaving it there or trying to pull it out with lots of force.

Could be the transfer case switch. That is one reason I want to bypass it all together to see if the problem still exists...

Do I still need to remove the transfer case shield?? I do know where the switch is suppose to be but can't do a visual and can't get my big paws up in there to feel for it??

What about the connector from the hoses to the transfer case switch???

Am having trouble trying to find that part should it be bad..

Bill

Post by **HenryJ** » Wed Oct 05, 2011 10:05 am

The connector at the switch may be fused to the hoses. You may not be able to replace it. It is not likely to be bad though.
Pulling the t-case shield will be easier. A body lift helps lots too. It is tight. The t-case switch thread has pictures IIRC.

roadrunner · Post by **roadrunner** » Wed Oct 05, 2011 5:18 pm

IIRC some of the vacuum hoses for the front drive engagement are zip-tied to various points as they progress from their origins to their termination points. Not fun to get to and removing the T-case shield should help but they are still tight to get to as they run up between the transmission and the body/firewall areas. I understand the "big paws" problem as I have the same problem. Not fun in tight places and usually costs me some "hide". I would avoid the "lots of force" method as you don't know what that line is tied to. Might damage something rather expensive to fix such as wiring or sensors (wiring also). Better to abandon an unused line and run a new one to replace it than cause more repair problems. Also I am not saying your switch IS bad just telling you how to verify it ISN'T so as to eliminate another possible gremlin. Since you have eliminated the T-case vacuum system and do not lose vacuum in the HVAC system without it that narrows the search considerably. There is just not that many parts that carry vacuum in the front engagement system. That makes it a process of elimination and checking for vacuum at the vent line is a good place to start that process so as to verify the T-case switch is good. Also doesn't cost anything other than a little time to verify. From your posts it looks unlikely that there is a problem with anything that is active in 4wd only as you are having trouble in 2hi as well. This helps narrow the search eliminating the 4wd engagement vacuum lines as likely suspects. Only the 2wd circuits then remain which includes the vacuum supply from wherever you disconnected it in previous tests to the T-case switch and including that switch.
Sorry for the lengthy post but I wanted you to be able to see the diagnostic process I've been thinking through on this problem has been well considered in depth and not just throwing out hap-hazard guesses. Don't mean to sound lecturing just explaining in detail.

okaussie · Post by **okaussie** » Thu Oct 06, 2011 12:33 am

My thoughts exactly. I am 6'4" and weigh in at 300lbs. size 14 shoe. So I have BIG PAWS.

There is a route that I have picked which protects the hose and gets me there with three bends. Down from the "T" fitting and through the frame rail to the crossover, down the crossover then right into the switch. It is inside most of the way. I have already bought new hose and waiting for time to troubleshoot it more to verify where my problem lies.

I really think that the hose is bad. Even in 2Hi it does it, so I am thinking the switch is okay.

I will check the switch as stated above by listening and feeling the vent tube for vacuum.

when I know more I will let you all know...

TIA

Bill

RebelKid1822 · Post by **RebelKid1822** » Wed Oct 26, 2011 7:12 am

well last night i got a temporary fix for my vacuum problem. i knew i had a leak somewhere between the engine, trans case and front axle. being as its ohio and cold and always dark when i came home i chose to not replace the three lines right now. instead i came up with a ten dollar fix. i ran a vacuum line from the main feed T by the resivour. i ran the line up under the hood and doorjam and into the left dash, and attached a plastic fuel shutoff valve. i ran the second line from the dash to front axle pod. my new lazy man system worked, the pod engages and disengauges when i turn the valve. i jacked up the right side of my truck to make sure my hubs were locking and unlocking fully. they were. the vavle when closed dose not allow any vacuum by. so for now it will be a great fix. i took my truck out to the woods to give it a try. it only took me a few minutes to realize i have nevr had 4x4 since i got it. when spring comes and it gets warm i will replace all the original factory lines and get the 4x4 back to how it whould be.

okaussie · Post by **okaussie** » Wed Oct 26, 2011 7:28 am

It is suppose to freeze at 29 degrees here tonight, so my swapping of the vacuum hose is, too, put on hold.

What I am going to do is unplug the hose from the T to transfer case switch, remove it from the transfer case then have the wife use compressed air to find out which line on the transfer case end is the real line. I think mine has a leak and causing my problem. When I find the right hose, I am going to replace it, reroute it better and let the old one be. Mine is zip tied somewhere along the line and I can't pull a new hose by attaching the new to old and pulling it through.

Hopefully that will fix my problem with the HVAC and assure me that I have enough vacuum to engage the front axle.

Bill

Horsehammerr · Post by **Horsehammerr** » Sat Jan 26, 2013 5:30 am

So, how can my front drive shaft be turning and no axle motion ? I put my truck on a lift and raised the front and rear off the platform . Engaged 4x switch, it clicked and the drive shaft started turning but not the axles ?? I just drove a few hundred feet and switched in and out and back into 4x. I then left 4x engaged put in park, set the brake and lifted one front wheel. The wheel turns easily by hand. this tells me I'm not in 4x. What should I check next. My vacum pod shifts in and out very simply with the dash switch.

Post by **HenryJ** » Sat Jan 26, 2013 8:11 am

Horsehammerr wrote:So, how can my front drive shaft be turning and no axle motion ? I put my truck on a lift and raised the front and rear off the platform . Engaged 4x switch, it clicked and the drive shaft started turning but not the axles ??

The front axle must rotate a little, pushed by the rear axle, to allow the shift collar to engage the right front axle. Otherwise the carrier just spins around the left axle shaft via the spider gears.

I just drove a few hundred feet and switched in and out and back into 4x. I then left 4x engaged put in park, set the brake and lifted one front wheel. The wheel turns easily by hand. this tells me I'm not in 4x. What should I check next. My vacum pod shifts in and out very simply with the dash switch.

if slowly rotating that tire back and fourth did not engage that axle and it did show on the dash that 4x4 was engaged, that does sound not quite right. If the dash switch indicates the front axle has engaged, I too would assume the system is working properly. Still we do need to confirm everything.
Are you REALLY sure the vacuum actuator is moving the cable?
That may be your next step in diagnosis.
Remove the battery and tray to access the actuator. Apply vacuum to the actuator. Does it move? Now apply vacuum at the line source checking for leaks and dry rot. A hand vacuum pump will be useful and a good investment for this.
If everything works properly thus far , remove the cable and shift mechanism from the front axle and test again. Be sure to check that it had been installed properly and engages the shift fork as it should. If all this checks out, the next step is to dig deeper into the front axle looking for a problem with the shift fork or collar.
If all that checks out, work toward the differential and spider gears.

Horsehammerr · Post by **Horsehammerr** » Sat Jan 26, 2013 8:15 am

I removed the headlight and watched the cable move in and out about two inches. Is that the right amount of travel ?

Post by **HenryJ** » Sat Jan 26, 2013 8:19 am

Horsehammerr wrote:I removed the headlight and watched the cable move in and out about two inches. Is that the right amount of travel ?

Is the dash light showing it engaged?
If it moves that easily you may have a broken cable? But then the dash light would not engage. That makes the shift mechanism suspect. Either not properly engaging the shift, or problems with the shift fork.

Horsehammerr · Post by **Horsehammerr** » Sat Jan 26, 2013 9:48 am

Horsehammerr wrote:I removed the headlight and watched the cable move in and out about two inches. Is that the right amount of travel ?

ooooooooooooooh well, thanks anyway. I figured it out my self.

Post by **HenryJ** » Sat Jan 26, 2013 10:31 am

Horsehammerr wrote:
Horsehammerr wrote:I removed the headlight and watched the cable move in and out about two inches. Is that the right amount of travel ?
ooooooooooooooh well, thanks anyway. I figured it out my self.

And the winner is?????

ApproachMedium · Post by **ApproachMedium** » Fri Feb 01, 2013 10:10 pm

For what its worth my vac actuator was totally fallen to pieces when I got my truck, but I had no idea. I would push the 4x4 high button and get a light that I was engaged, axle would spin but I guess the wheels werent. I took it in for some other repair at the mechanic and he pulled out the obliterated vac actuator and told me to go find a new one and that my 4x4 didnt work. I said I thought it did because I tested it, and he said without that piece, its def not working.

It is possible for the cable to brake. I know my cable is sort of jamming up and wont fully disengage but I can still go in and out of 4x4 and drive normally, for now. Ill change the cable when it gets warmer out.

Horsehammerr · Post by **Horsehammerr** » Sat Feb 02, 2013 6:09 am

HenryJ wrote:
Horsehammerr wrote:
Horsehammerr wrote:I removed the headlight and watched the cable move in and out about two inches. Is that the right amount of travel ?
ooooooooooooooh well, thanks anyway. I figured it out my self.
And the winner is?????

I pulled the cable housing loose from the front differential only to find the cable just slipped right out without releasing the snap ring. WTF ? Ah hah ! I say to my self, Hey stupid, you never snapped the cable in when you replaced the axle seal. Funny the dash lights all worked, 2Hi, 4Hi, 4Lo but I do remember who designed this system. Anyway both ends of the cable really must be connected to make the front drive engage, so it's fixed. And the Winner Is stubborn pursistance.

Oh, and the cable only moves about 9/16"- 5/8" at the actuator under the battery.

RebelKid1822 · Post by **RebelKid1822** » Fri Oct 18, 2013 8:04 am

just wanted to comment that it has been over two years since i did my "$10 fuel valve fix" for my 4x4 vac. i have had no issues with it and my 4x4 works great to this day.

Horsehammerr · Post by **Horsehammerr** » Fri Jun 27, 2014 6:57 am

RebelKid1822 wrote:just wanted to comment that it has been over two years since i did my "$10 fuel valve fix" for my 4x4 vac. i have had no issues with it and my 4x4 works great to this day.

Gotta' love a TRUE REBEL. I'm thinking a new design " Posi-lock" system that eliminates vacuum to the 4WD system completely.

RebelKid1822 · Post by **RebelKid1822** » Fri Jun 27, 2014 7:00 am

Keep me posted on that mod.

Horsehammerr · Post by **Horsehammerr** » Fri Jun 27, 2014 7:02 am

Horsehammerr wrote:
RebelKid1822 wrote:just wanted to comment that it has been over two years since i did my "$10 fuel valve fix" for my 4x4 vac. i have had no issues with it and my 4x4 works great to this day.
Gotta' love a TRUE REBEL. I'm thinking a new design " Posi-lock" system that eliminates vacuum to the 4WD system completely.

If I could just figure out how to hook a locking "T" handle cable to the shift hook-up at the front differential ? Then I will save the near $300 for a Posi-lock cable that doesn't even disengage far enough to relock.

RebelKid1822 · Post by **RebelKid1822** » Fri Jun 27, 2014 7:09 am

All you would need is to make a bracket where the vacuum pod is, then measure with string how long the cable would need to be. Im sure you could attach-weld the end off the old pod to a cable assembly. There are lots off places that can make custom PTO cables for trucks. Something like that should work. By me in Ohio there is a place called custom Clutch that can do that. After that, just putting a hole I. The firewall to the dash is no biggie. Keeping it well lubed would be key. It sounds pretty doable.

Horsehammerr · Post by **Horsehammerr** » Fri Jun 27, 2014 2:42 pm

Well, at this time, I found two vacuum leaks at the famous T fitting by the brake booster and replaced 12 " of 5/32 tubing. That's all folks, I'm back in push button 4WD again. Who knows about the future. I will change the transfer case switch since I spent $44 on it.

RebelKid1822 · Post by **RebelKid1822** » Fri Jun 27, 2014 2:52 pm

Do u mean the screw in switch with the ball on the bottom that the vacuum lines hook to? If so that seems high. They are like 16 at AutoZone