4x4 not working correctly

HCO4x4 · Post by **HCO4x4** » Sun Apr 13, 2008 5:23 pm

My 4wd feels and sounds like its locking in but when i get stuck i dosnt help at all. the wheels dont even try to crawl. any ideas?

Post by **HenryJ** » Sun Apr 13, 2008 5:27 pm

Lights show 4x4?
Front axle engaging?

Remember with a locked rear it is still only three wheel drive at best.

HCO4x4 · Post by **HCO4x4** » Sun Apr 13, 2008 5:29 pm

the lights work fine. just as they should. it saounds like the front axle is engaging. but not even one front wheel is helping

green02crew · Post by **green02crew** » Sun Apr 13, 2008 5:47 pm

Maybe vacuum actuator? That way it would say it is in 4 but wouldn't be and I think you would still here it click in? Just a thought. Thats why I wish ours were a simple lever soo much more reliable I think and just as convenient.

HCO4x4 · Post by **HCO4x4** » Sun Apr 13, 2008 5:57 pm

i feel the truck jerk when i put it in 4lo. could it still be the vaccume actuator?

green02crew · Post by **green02crew** » Sun Apr 13, 2008 6:27 pm

Well 4 low affects the rear wheels as well so that is understandable. I found this thread you may want to read through since it might help narrow the issue down.
http://www.s-10crewcab.com/phpBB2/viewt ... four+wheel

roadrunner · Post by **roadrunner** » Sun Apr 13, 2008 8:01 pm

If electricals appear to functioning correctly then you are down to: no vac to transfer case switch, faulty transfer case vac switch, faulty vac actuator, broken/stuck actuator cable (very likely as they give lots of problems if not serviced and lubed regularly), broken shift fork in front diff, or broken front diff-if axles are okay (should make noises even if not engaged when driving even in 2wd). Provided you haven't (god forbid) lost your front driveshaft or broken internals in transfer case (should've made lots of abnormal noises though).

JaVeRo · Post by **JaVeRo** » Sun Apr 13, 2008 8:03 pm

With the engine running, transmission in park, put it in 4wd and crawl underneath. Try turning the front driveshaft. If it still turns freely, then the transfer case is not engaging. If the front driveshaft is lock then jack up one front wheel. If the driveshaft is locked and the front wheel turns freely, then the front differential is not engaging.

The transfer case will lock without the engine running but you have to start the motor to get vacuum for the front axle to engage.

James

HCO4x4 · Post by **HCO4x4** » Sun Apr 13, 2008 8:08 pm

thank you for narrowing it down a little more, and ill have to see for sure if the axle is engaging. will post tomorrow.

HCO4x4 · Post by **HCO4x4** » Mon Apr 14, 2008 1:59 pm

in drive both back wheels spin and the front driveshaft spins but the front wheels do nothing. i can spin them freely in 2 or 4wd. i hear something like a quiet binding front the front but only if i put my head close to the wheel well.

green02crew · Post by **green02crew** » Mon Apr 14, 2008 4:35 pm

I'm sticking to my initial "gut" feeling that it is the vacuum actuator.

HCO4x4 · Post by **HCO4x4** » Mon Apr 14, 2008 6:40 pm

i took the battery and tray out then i put the truck in the air started it, put it in drive, and also 4 wheel drive. the front driveshaft spun but not the front wheels. i had my dad step on the brake while i pulled the cable out because i saw the actuator struggling. as soon as i pulled it out, my father let off the brake and 4wd was working again

so it has to be either the actuator or the cable. the cable needs a little pressure to extend but i dont think it is coroded. looks like im going to be buying a new vaccum actuator. know where i can get one cheap but not a peice of crap?

P.S. thanks for all the help fellas.

green02crew · Post by **green02crew** » Mon Apr 14, 2008 6:52 pm

$43 synergyoffroad is the cheapest but with shipping most likely the same as picking it up at Napa or Autozone both around the same just couple bucks difference so $50 Autozone and $52 Napa.

HCO4x4 · Post by **HCO4x4** » Mon Apr 14, 2008 7:18 pm

sweet thanks again

roadrunner · Post by **roadrunner** » Wed Apr 16, 2008 2:21 pm

Make sure you lube that cable up!!!! It takes much less than you think to stop the actuator from pulling it all the way engaged.

HCO4x4 · Post by **HCO4x4** » Sun Jun 29, 2008 4:33 pm

My 4wd isnt working once again. The front diff is not engaging. I read something about a collar to lock in the axel and im going to check lube tomorrow. Suggestions?

HCO4x4 · Post by **HCO4x4** » Tue Jul 01, 2008 5:43 pm

Should i take it apart and look around or take it to a shop?

roadrunner · Post by **roadrunner** » Sun Jul 06, 2008 11:20 pm

Lube lube lube your cable. I had lots of trouble with mine especially if you don't use 4x4 regularly. As stated before very little binding in the cable will stop it dead. Check also to make sure the screws that mount the actuator diaphragm to it's bracket haven't worked loose. Mine did effectively reducing/eliminating cable movement enough to stop front axle engagement. BTW, use something like PB Blaster or such and not WD 40 or the like as the latter tend to dry up quickly and also attract moisture causing further problems.

HCO4x4 · Post by **HCO4x4** » Tue Jul 08, 2008 11:46 am

i drained the diff, took the 3 bolts out holding on where the cable enters, I've come to the conclusion that i can lock the diff in if i pull the cable by hand. Is there some type of adjustment like on a brake cable of a bike? There is something that looks like it to me but I guess that is just to hold the cable intact and dose not adjust it. I'm going back out to take the battery and tray out and have a look.

HCO4x4 · Post by **HCO4x4** » Tue Jul 08, 2008 2:29 pm

I've got it all back together now and still cannot get the diff to engage without pulling the cable by hand. The actuator is clearly working. There has to be a way the tighten the cable.

Post by **HenryJ** » Tue Jul 08, 2008 3:35 pm

If the cable is too long, then it is falling apart internally. Likely a frayed section. Replacement will be required.

HCO4x4 · Post by **HCO4x4** » Tue Jul 08, 2008 4:14 pm

OK thanks for the reply. I guess I'm off to buy a new cable.

HCO4x4 · Post by **HCO4x4** » Tue Jul 08, 2008 4:32 pm

I didn't see one on synergy, Ebay or Google. Know where I can get one? Also, what is the difference between this cable and the Posi Lock cable besides manual engagement?

BADs Crew · Post by **BADs Crew** » Thu Jul 10, 2008 6:32 pm

The Posi-Loc replaces the actuator. You will still need the cable from the actuator to the front diff.

Post by **HenryJ** » Thu Jul 10, 2008 6:37 pm

Actually, they redesigned and it replaces all of it:

Posi-Lok front axle actuator

BADs Crew · Post by **BADs Crew** » Thu Jul 10, 2008 6:59 pm

Didn't know that.

HCO4x4 · Post by **HCO4x4** » Fri Jul 11, 2008 1:49 pm

Ok thanks. I've found a cable but its called the control cable. Is that the one I want? Does anyone know where I can get the correct one?

BADs Crew · Post by **BADs Crew** » Fri Jul 11, 2008 4:57 pm

LMC page 140 part #8, $49.95

HCO4x4 · Post by **HCO4x4** » Sat Jul 12, 2008 7:20 am

Thank you

HCO4x4 · Post by **HCO4x4** » Fri Jan 02, 2009 1:48 pm

Just installed the new actuator and I've got the same problem as before. The cable seems to be a bit too long and the actuator can't seem to pull it all the way in. I have to give a little push to pull it all the way in but the diff. still will not engage. Ideas?

roadrunner · Post by **roadrunner** » Fri Jan 02, 2009 5:00 pm

Check to make sure the screws that hold the vacuum pod to it's mounting bracket are not loose. I had the same problem and that was the cure for that problem at the time. Also check available vacuum at the actuator when engaged. Possible leak upstream from the pod. Also worthy of note that vacuum pod pulls quite a bit further than you think at full apply.

Post by **HenryJ** » Fri Jan 02, 2009 5:22 pm

Also keep in mind that the axle splines must line up for the shift collar to move and engage the front axle. It may not engage static. It needs to be moving.

YellowCrewCabber · Post by **YellowCrewCabber** » Sat Jan 03, 2009 12:16 am

HenryJ wrote:Also keep in mind that the axle splines must line up for the shift collar to move and engage the front axle. It may not engage static. It needs to be moving.

Hi jack. Is it better to engage/disengage while moving(under 3mph)?

Post by **HenryJ** » Sat Jan 03, 2009 8:03 am

4hi may be done at any speed. 4lo requires stopping or under 3 mph.
If you are stopped when you switch. Ease into it so the front axle can engage.