ZR2 rear axle upgrade.

[s10 again]

Yep we will take pics and if anything other than bolt in occurs we will post. But I think i'm going to be ok.

The rear is out of an 03 zr2 as well and has 76k on it don't know what cab style. It should be complete with all brackets,cables and brakes for 850.00. A steep price I know the one one on Ebay was re-listed at 625.00. But no panhard bracket and up to 300.00 for shipping. This way I have some time to clean it up and no worries about getting it. We will see how it goes keeping fingers crossed we don't run into something crazy.

Chris.

[HenryJ]

That does not sound unreasonable for one in good shape. Mine was pretty depressing looking.

[Horsehammerr]

Just wonder how much ground clearance was lost with this upgrade ?

[HenryJ]

One inch at the center section. It now matches the clearance at the bottom of the plate for the U-bolts.

[s10 again]

Well I could not pick up the axle yesterday but went and got it this morning. It did not have the calipers on it but the way it looked I figured I would just swap mine over. After getting it home wife reads tag hooked on one bent lug nut and it says 99 s10. Closer inspection shows rusted out dust shields and bent lug my be a bent shaft flange. Also Someone half ___ bent up a new metal brake line on one side.

I'm heading back to the JY to see if maybe the wrong one was sent of if this is a trap to tell someone it is a lower mileage/newer year to get them to lay down more $$$. Maybe they will take back or give a partial refund.


Wish me luck!!!!

Chris

[HenryJ]

Yikes. Sounds like this is getting to be work!

[s10 again]

Well bait and switch I think is the name of the game. Went back to JY and he gives me the story. When they first looked up the rear on the computer he said there was one listed that was an 03 with 10k . He called the other JY to confirm they said typo that it was a 99 with 76k. He told me since they were listed as interchangeable he did not think to tell me it was a 99 but that it does show as 76k. If I install it and have any problems within 90 days they will make good on it. As for brake parts he said they usually come with them without charge so they did not charge for them. The bent lug I was told to pull the rotor and see if the flange is bent or just the lug. If it is the flange let them know.

I'm going to work on getting the axle in the garage this eve. or tomorrow to pull the cover and have a look see. If anything looks off even a bit I'll haul it back up there and fight with them.

But now a new dilemma should I put any money more than fresh oil and cover gasket into it before I mount it? I would hate to even pay for paint and end up just having to send it back.But hate to put it under my truck looking like it does.

A lesson to anyone getting a junk yard zr2 rear make them put on the receipt year and mileage rear you are getting. Mine just says zr2 rear axle assy. You can't hardly prove either unless it comes with a tag stating the year. But it will give you some extra footing to get what you pay for.

Chris.

[HenryJ]

Pull the cover and have a look. Finding out if the flange is bent will be hard. A dial indicator would be the best check, but most don't have one of those. It is not going to be something you can actually see probably.

You will need a stud at the very least.

It is up to you, but don't get taken. There are better deals out there. $850 for a rough 1999 axle is pretty steep. $850 for a good low mile 2003 axle is still on the higher side, but probably acceptable.

[s10 again]

HJ, From talking to them it will be a fight if I don't try it out. But if I pull the cover and it is not near perfect then I'm going to make it look as if I bolted it in then I'll take it back and tell them it whined like crazy. Make them stay good with that 90 day warranty. I just got back inside from out in the cold blocking the axle up on the trailer so I could get the drums off and look at the flange. Crazy taking a hammer to something I laid out 850 bucks to. The rotors are toast so hammering them off did not bother me. I knocked out the bent stud and it looks like the flange is ok but like you pointed out hard to really tell. I spun the yoke around several times and it is smooth as silk. Reversing the spin shows no real slack in the gears nor does rocking the yoke back and forth. If I take it back they will likely want to exchange it meaning I might get something worse!

I'm going to try to get it in the garage tomorrow I hope and get that cover off. That will be the deciding factor.

I read your swap post it looks like you used all your brake parts on the new rear. Pleas tell me that I can swap out everything down to my dust shields to the zr2 axle. I think I will buy all new brake hoses though. Will all the zr2 hoses work or just the ones going to the calipers ? I'm thinking the line from the frame to the axle on the zr2 might be a little longer which is good since at some point I'm going to lift.

Now for something interesting. I did get the panhard bracket as well as the panhard bar. So I'm guessing all I need is the zr2 frame bracket or have one built up to have a panhard in my zr5.


Chris.

[HenryJ]

Forget the panard bar. One of our shocks is in the way and the exhaust is in the way to move it.

I do understand that they want to sell you that axle, but your purchase was not one that was sold as is , no refund was it? That would be silly. You should have the right to refuse it and get a refund if it is deemed unacceptable in your opinion.

Now the rest of the story.

Yes, all your brake stuff will work just fine. You can even use your left rubber brake line and the center rubber line from the truck to the axle. You will need to use the ZR2 rubber line to the caliper on the right side.
You have to pull the axles to replace the backing plates so pick up new seals along with that gasket for the cover. If the pinion is not leaking , leave it alone. It can be replaced later if it is a problem.

I fit looks good internally, fix it up and install it. That is what I did and mine looked really pathetic.

[HenryJ]

Information on my swapped ZR2 rear axle:
VIN# 1GCCT19X138118459
Us built, General Motors, Chevrolet truck, 4001-5000 HYD brakes, Sm Conventional cab-4x4, 1/2 Ton nominal, Two-door extended cab, 2003, assembly plant Shreveport, LA

One inch spacers are just enough get rid of the "Dumbo ears" look. Much better now. Thanks Steve!

[s10 again]

Ok guys,
Weather gave us a touch of a break so we put the axle in the garage. Just pulled the very rusty cover and everything inside is in great shape. A small amount of play in the spiders but nothing to worry about. Surprisingly there was only a very very small amount of very fine metal in the oil.(looks to never been changed) Are the clutches in the g80 metal? I saw nothing that looked like clutch material.

The inside makes me feel better than I did before. Still not the best but this truck has got to get on the road ASAP. So I guess it is a keeper. Next up(you guys are going to say I'm crazy) is to tape off all sensitive parts reinstall cover. Then sand blast and paint. Before I refill I will replace axle seals and get new rear cover with gasket.

The gear oil smells a bit different synthetic? I read on another site that GM started using Synthetic without lsd additive as early as 98 on F/S trucks to help with problems they were having with the g80. Any idea if the General might have started using synthetic on all 8.5 applications with the g80? One more thing Autozone has 2 different axle seals listed for the 8.6. One with lsd one without. Which one for the g80?

HJ,

Since we can't use the track bar I might cut that bracket down keeping just what is needed to hold that brake line what you think? My axle checks same as yours by vin just a 99.


Chris.

[HenryJ]

... Are the clutches in the g80 metal?

A combination of metal and bi-metal lined.

The gear oil smells a bit different synthetic? I read on another site that GM started using Synthetic without lsd additive as early as 98 on F/S trucks to help with problems they were having with the g80. Any idea if the General might have started using synthetic on all 8.5 applications with the g80?

Recommended fluid is still listed as 1052271 through 2004 for the G80 equipped rear axle s-series. It is possible the later model full size use a G80 with different clutch material. I have heard both rumors too, but no conformation or specifics. I guess if it meets the GL5 specifications it could be ok. I have not found one suitable yet though, JMO. More than likely the smell is friction modifier. That stuff really stinks.

Autozone has 2 different axle seals listed for the 8.6. One with lsd one without. Which one for the g80?

My guess is they are listing the G80 as a LSD (limited Slip Differential). That would be my choice. You have a 50/50 shot at getting it right.

I might cut that bracket down keeping just what is needed to hold that brake line what you think?

Go for it. I even thought about a custom bracket so I could ditch the u-bolts that hold it on.

[HenryJ]

My new cover showed up today. Moser Engineering Performance cover



OMG I thought the LPW ultimate cover was beefy. This thing is 3/4" thick! And it has oiling channels for the side bearings. This cover is my new favorite.
Hopefully I find time to install it this weekend. I'll take a picture of it installed.

[s10 again]

Sweet I want one but at 160 bucks I'll have to save after buying the rear. It does look tough so worth the green or plastic. Are you going to paint it if so what color? I'm going to buy a new cover (Stock type) thinking of painting it to match the flares,grill. Don't know why the only ones thats going to see it for a while are the ones that I might run over.


Chris.

[HenryJ]

I will leave it the raw color. A shot of clear is a good idea, thanks for the reminder.
If you buy a cover, get one with the oil channels to direct oil to the side bearings.

I really liked my old cover and sold it to help finance this one. I have done pretty well selling off parts of my old axle, thank goodness.

[HenryJ]

The channels to lube the side bearings:


Installed:

[fallvitals]

Wish I was followin this thread, just browsed through it, and read bits and pieces ill have to read it all soon, but nice work Brule!

[s10 again]

Well we are well under way tonight we got the 8.5/8.6 axle stripped of the axle shafts and brake parts. Man those 8 backing plate bolts a bear. And it took a few tries with a magnet to get the c-clips out and not loose them in the gov-lock.

But now I have hit a small snag or two. The axle seals I got from Autozone won't fit. The inside fits the shaft but the outside is too big by enough that the axle tube fits inside the seal. The part # is 4762n just in case anyone else runs into this they will know these are a no go.

Now is were I for help from HJ(hope you chime in) or anyone that have swapped in a zr2 axle or have a zr2 and replaced the rear wheel seals. Were did you get your seals and do by chance do you have a part #.

Next is for HJ. In your swap post you had to change the right side brake hose. I'm wondering why as my hose is a touch longer than the zr2 one? Is it being longer a problem?



Chris

[border man]

I don't know any part numbers, but according to most of HJ''s mods he usually references and uses parts from NAPA.

[s10 again]

I might have the seal figured out. Oreilly has the measurements of their seals listed. They have the same part numbers as autozone on the seals. I think it is 8835S and has the same inter diameter but the outer is like 1/4 inch smaller. I got the one for a LSD thinking they meant the g80 which we know is a locker but confuses many as a LSD. I did not think they put LSDs in s10s. I thought they would be the same size just made to hold up to different oil requirements.

I guess this is what I get for thinking to much!

Chris.

[killian96ss]

LSD = limited slip device, which is the same as a G80. GM uses the RPO code G80 for all LSD's whether they are clutch types posi's or lockers.

Steve

[s10 again]

Ok got the seals Timken 8835s. This is the non-LSD. Kind of funny when we returned them today to AZ the guy told me it was everyones lucky day. Lucky me I got the last two they had and they were cheaper. Lucky for them because I only paid for one of the others but got two at 7.99 each the 8835s were 3.99 each. We took our penny refund and told them "I'll be back" to spend it later.

Moving on we got the rear under the crew and the u-bolts bolted in. Also put the backing plates on but due to 29* wind and snow blowing in around the S10 that is only half way backed in the garage along with the only heat being a 500watt light I had to retreat for the night.

I want to give an early impression I have. Taking out the stock rear felt much like working on a mid-sized car. Putting in this ZR2 rear has felt like working on a full size truck. I know it truly is not that big. But the extra weight and width is noticed. This even though the axles and brakes have yet to be installed. I have yet to drive the truck but I'm already happy with it.

Or maybe I'm being .

Chris.

[HenryJ]

...maybe I'm being...

No, that is a positive attitude!

[s10 again]

...maybe I'm being...

No, that is a positive attitude!

Cool because I thought I might be losing it. , Now whats the scoop on that right brake hose if you don't mind sir. The stock one on mine is a tad longer than the zr2 hose is that a problem.


Chris.

[HenryJ]

The stock one on mine is a tad longer than the zr2 hose is that a problem.

Yes. It is too long and will not fit the bracket.

[s10 again]

Well I swear if it is not one thing it is ten others. First the progress axles are in brakes all bolted up even filled it with oil things were looking good. Then another snag. I should have taken the breather hose off the 8.5 when it was still out. But I had to cut the stock one and thought I might have to cut the 8.5 one then join them together. It turned out I was ok with the cut one. When I went to remove the 8.5 breather hose the fitting easily snapped off flush with the housing. And some moron at GM decided to not make that a threaded fitting but a press in.


So anyone have any ideas on how to deal with that?

*edit* Had a second to chill and I think I have a plan. Anyone see a problem with sealing off the fitting in the housing . Then removing the cover and drilling a hole in it at the top opposite the ring gear and installing a fitting for the breather.

Thanks.
Chris

[killian96ss]

If you are going to remove the cover, why not just remove what's left of the plastic breather fitting and install a new one? If you don't like the plastic fitting, you could install a brass pipe fitting with a barbed hose end. All you need to buy is 1 tap, 1 brass fitting, and some hose. If this happened to me that's what I would do!

Steve

[s10 again]

Thanks for the reply Steve,


The problem is the fitting is steel and looks to be pressed into the housing It broke because it was rusted . I tried to remove the one from the stock rear end just to see what I'm up against but it does not budge.

Chris.

[HenryJ]

You may be able to use a tap to create threads in the broken fitting. Then slide a larger nut or stack of washers over it. Thread a bolt into it to pull it out. The other option is to use a punch or small chisel to drive it in. Either solution is going to require pulling the cover.
A press in replacement is probably not going to be a viable solution. It is very likely that the "tap and thread" a new fitting will be the best solution.

[s10 again]

I think I might try to punch it through but it is badly rusted. I want to try to avoid getting metal shavings in the housing if I can. Any problem with moving the fitting to the cover?

Right now my plan is to move forward and bleed the brakes get the drive shaft bolted up and drive it for a day or two. I want to put a few miles on it to check it out before putting more money and time in it. I'll just keep it out of deep mud and water. Then I'll attack the breather.


Chris.

[HenryJ]

I want to try to avoid getting metal shavings in the housing if I can.

Stuff a rag in there to catch the pieces

Any problem with moving the fitting to the cover?

It needs to be out of the oil dispersion so that it does not bleed oil. Axle tubes are a better place. There is an axle tube bolt for the brake line that incorporates a breather tube. That might be an option.

[roadrunner]

You might want to count your blessings that fitting broke off now and not later unnoticed allowing water etc to get into your new rear end ruining all your hard work or at best making more work and expense.

[s10 again]

You might want to count your blessings that fitting broke off now and not later unnoticed allowing water etc to get into your new rear end ruining all your hard work or at best making more work and expense.

Very very true, Thanks I needed A silver lining after all the set backs and not all involving the crew cab. Another high point was getting her set back down on all fours again. I really like the wider rear stance it does accent the bed bulges.

A few more minor things and I'll get to take it for a spin and check out how that junk yard rear feels. We are having a little fight with getting the brake bleed . But I'm sure they will pump up with a few more bleeds. It might even just be the calibers needing to reset since I added new pads while I was in there. And I need to bolt up the drive shaft. I wanted to see how much further it goes into the t-case over the stock rear. Plus I want to chase the u-strap bolts with a tap they look a little rusty.

After I put a couple of dry miles on it I'll fix that broken fitting one way or the other. Once all is done I will post a few pics.

Thanx to all.

Chris

[rlrnr53]

Sounds like Mr. Murphy decided to move into your garage.A little patience and elbow grease will move him out.

[s10 again]

Sounds like Mr. Murphy decided to move into your garage.A little patience and elbow grease will move him out.

He use to live next store but then we started feeding him and he moved into the garage.

Elbow grease some patience and less food might force him back next store I hope!!!

Chris

[s10 again]

Finally my Zr2 rear swap is done. I still have to fix broken breather tube but that can hold for now. We got the brakes to come up last night but a dead battery kept me from a test drive till today. Please don't take the time it took me to do my swap as meaning it is complicated or that time consuming. My broken wrist and weather stretched this swap out. As HJ pointed out in his post this is truly a bolt in affair. With the exception of the right caliper brake hose. (which is still bolt in you just need the zr2 hose). I tried to bend and twist that stock hose to make it work but it is just too long to fit directly and not long enough to loop it to fit.

Also For those like me that have a low riding crew cab(Mine is sagged) keep an eye on your drive shaft. The 8- 1/2 has a longer snout and moves the drive shaft 3/4" to 1" further into the t-case. My D/S took a little fighting to get it to move into the case enough to get the u-joint into the saddle of the rear yoke. I'm not comfortable with the fit and fear if I hit a big hole and have any load on the truck the slip yoke might bottom out in the t-case. If the truck were up to stock height I think it might be ok. If you have any lift this could be a plus and put your yoke back in the t-case like stock. For now my money well ran dry so I'm looking at some axle set back plates used in s10 v-8 conversions. These cost around 30 bucks and move the axle back 1/2 an inch. This will hopefully be temporary till I get some lift.

Another thing to look at is the left e-brake cable is very tight on full droop as HJ pointed out. Looking at it I might choose to lower the e-brake bracket on the frame to loosen it up a little. I don't think it hurts anything short term but long term I'm not sure.Other than those things this swap is so easy A one arm man can do it.

Now for driving impressions. Well first thing is my truck is much smoother now. That stock rear was wasted and from the feel of it was having issues when I first bought the truck. It still has a little vibration that I need to find but it is much better now. The truck feels more stable and coast better now as well. Then there is the hill test. . We have a hill going into our back yard that when muddy is near imposable for a two wheel drive to get up. The s10 would do it in 2wd before the swap. But I would feel a jar as the g80 kicked in. This likely was not the g80 but the carrier getting smacked around from worn out carrier bearings as the g80 locked. The 8 1/2 g80 is seamless as it engages. The only hints that it kicked in was one- I was still moving and second- The rear got out of track with the front. I have a second hill that even with 4wd can be unclimbable when wet. This was where I could watch both tires in the side views. Starting up very slowly I watched the right rear break loose and then both were spinning. Again I never felt the g80 lock. And no the s10 did not make it up this time.

I am really liking the wider rear stance. It looks much more natural now and gives reason for the bed bulges. It just looks more stable and as I touched on above it feels that way too. I can see that I lost some turning radius but with all the positives I can live with that.

Continued

[s10 again]

I would like to pass on some tips.

1. If you are getting your rear end from a junk yard tell them you want to look at it before they pull it. Be careful if the rear is in a wrecked truck. If they have to order it from another yard and you can't see it before hand don't give them more than half the money till they get it and you can look it over. My fool self paid in full before seeing what I was getting. It was played up as being complete with brakes and 76k on it. I believe it is a low mileage rear but was in rough shape for the 850$ price tag.

It was very rusty with no calipers,useless rotors and disc shields were rusted away. Looked like it had been sitting directly on the ground for sometime. When I talked to the yard about the condition I could tell it would be a fight to get my money back without it being broken and maybe even then. Best I could hope for would be an exchange that might have been worse. So I learned something. Looking at the tag attached to the rear I could see it had a place for grade. If you have to order anything from a junk yard ask about what grade part you are getting and have them put that on the receipt. Mine was a C grade for reference.

2. spray down all bolts with penetrating oil a week ahead of swap. HJ"s advise as well. But I knew this from wrenching on junk for a long time. My favorite is PB magnetic penetrating oil.

3. I used vise grips to clamp the center brake hose. This not only keeps brake fluid loss down but keeps air from working its way further up the system.

4. Once you unbolt the drive shaft wrap tape around the u-joint to hold the caps on.

5. Check the wheel bearings and replace at least the seals. If you are comfortable with the rear you got I would replace the bearings as well.

6. Leave the shocks attached to the u-bolt plates. It keeps the plate handy to bolt back in and means two less bolts to mess with.

7. HJ advised to not drop the springs. I will second that advise. HJ took his axle under the springs. I took mine out from over the passengers side spring. This allowed me to jack up the axle with my floor jack and wheel the center to the spring and balance it there. Then we wheeled a dolly under the axle and slid it off the spring onto the dolly. Install was just reversed. Even one handed this was very easy.

8. Another one from HJ that I second. this one I would have not thought of till reading about his swap. Before installing the axle get that fill plug loose. I don't think mine was as bad as his but it was though to get loose and easier to fight with than being under the truck.


Now the why do this swap.

I ask the same thing months ago the answer I got. The whole thing is beefer which I find to be true. The ring gear is an inch larger. The carrier and carrier bearings are larger.The gears in the G80 are larger as well as the g80 casing. The axle shafts are 1/2 inch thicker. The center of this axle is the same as used on many full size trucks. It has a ton of after market support. The ZR2 8-1/2 is also 4" wider than our crew cab axles. This moves the wheel and tires out 2" without the need for spacers.

Enough gibber jabber lets see some pics shall we.


The rusty 8-1/2



Inside the cases then outside. 8-1/2 left 7-5/8 right.






axle shafts 7-5/8 left 8-1/2 right.


Cut down ZR2 track bar mount. Could be removed and brake hose bracket welded to axle tube.

Next stance. Truck no lift no spacers. Tires 235-75 15s on ZR5 rims


stock rear



zr2 rear

Plumb bob string attached to zr5 flare.


stock rear


zr2 rear


I have a few more pics from the side but this is getting long and I feel that what I have does a good job showing off the ZR2 rear axle swap.

Thank you guys for all the help and encouragement during this swap.
Special thanks to HJ for all the help
And to HJ and Walt for keeping this wonderful forum from becoming another dead link without it I would have likely went back stock!!!

Chris.

[HenryJ]

Thank you. The pictures are wonderful!

[s10 again]

Thank you. The pictures are wonderful!

Chris.

[green02crew]

Found an axle out of a 2003 Zr2 with 103k on it. Higher mileage but they want it gone for $75. At that cost its doable and I'll have an axle waiting for when the time is right!

[HenryJ]

Perfect!

[green02crew]

Okay the seals are a pain in the rear end (pun intended) for me as well. Seems that I too have the seals that are too large and can actually fit over the axle tube. Is that a different style seal? Seems strange that many parts places would offer them for this application and be completely wrong. I picked them up at a Sanel's auto parts and they advised that was proper for my application. Should I just try it and see if they leak?

[ludwis]

It has been a while since I've posted an update, but I have to say HenryJ and you guys have come through again.

Long story short - my rear diff needed to be rebuilt (96,000 miles) and I was faced with the same decision many of you were. With all the info on the ZR2 upgrade and the 4x4 superstore in my backyard other wise known as Collis Truck Parts I was able to find a matching posi 3.73 ZR2 donor rear end.

I put on new backing plates and rebuilt the ZR2 rear. ALL other parts were reused from my ZR5 rear end. In order to reuse all the lines the brackets that hold the rubber lines on the axle were simply relocated a few inches.

I also updated my 2009 MML post to fix the broken picture links if you want to take a look at her.

[HenryJ]

Nice job! I spy a BSW rear spring kit on there, right?

[ludwis]

Nice job! I spy a BSW rear spring kit on there, right?

It most definitely is a BSW kit. The MML wouldn't be complete without it

[HenryJ]

Yep!
I think you were one of the first to follow that path. Great to see the truck is still going strong! You ARE going to love that rear axle. They should have made that part of the ZR5 package and added some Bilstein shocks.

[northsnoma]

About how much does the BSW kit cost? Sorry to throw the thread off-track..

[HenryJ]

About how much does the BSW kit cost? Sorry to throw the thread off-track..

You would probably need to call or email them for current pricing: Boise Spring Works Spring kit
TOLL FREE: (800) 585-5332

Contact form
http://www.boisespringworks.com/

Our page is still linked: http://www.boisespringworks.com/springkit.htm

[northsnoma]

Thanks HenryJ, just checked those 2 pages out before I posted this question. Didn't see prices so was trying to get a feel. I'll give them a call tomorrow

[HenryJ]

It has been so long ago now I would have to search posts to know for sure what I paid for mine. I think it was $135? Bennie paid a little more than that I think? I helped install his. After that steel prices went nuts! I am pretty sure we were closing in on the $200 mark at one point for a kit shipped?

BTW, they are Mountain time like me Let us all know what you find out

[northsnoma]

I am in the Flint area so their are many machine shops and specialty craftsman around that I would hope would be able to put something together from the photos

[HenryJ]

I am in the Flint area so their are many machine shops and specialty craftsman around that I would hope would be able to put something together from the photos

Best way to go! Keep it local and save the shipping charges.

[Horsehammerr]

Sorry about Jacking this thread but , I could not locate the answers I'm looking for. First my main steel brake line that attaches to the feed line to the rear "T" rusted through at the flare nut right there by that breather box. What can be done besides replace the line ? If that is the only answer can a new one be purchased and where ? I thought my rear calipers were gone and as I was finishing the driver side I spotted a wet "T" above the diff. and felt real dumb. Had wife pump brakes and " SQUIRT " out it came above my head, again head felt real dumb !

[HenryJ]

... my main steel brake line that attaches to the feed line to the rear "T" rusted through at the flare nut right there by that breather box. What can be done besides replace the line ? If that is the only answer can a new one be purchased and where ?...

Line can be purchased at the auto parts store. Cut the line back to where it is good and re-flare it add a union / coupler and a new piece of line.
I think they come in pieces starting from about 18". Chances are that if you need to replace all of it, you will do it in a couple sections. 6' pieces are all I recall seeing locally.
Another option is the salvage yard, but lots of work making sure it is better and clean. New line may be possible? GM or LMC? Probably not very cost effective though.

[Built2Bend]

If I were you I would also pay the extra $1 or 2 a foot and get copper brake lines so they won't rust from the out side again.
also if you replace the hole line you need to cut off and take the fittings on both ends of the line to the part store with you idk about every one ealse but my local part stores won't give you a line with your seeing your fittings first.







And becoulse this thread was brought back I'll ask a question also is a zr2 blazer and zr2 truck axle the same or are there and differences I need to worry about. Thank you

[rlrnr53]

Copper doesn't have the strength of steel, plus it is subject to fatigue failures. It is not allowed in W Va. for brake lines at state inspection. I have seen many failures of copper when used as brake lines, as the practice was common here because copper is easier to bend and flare.

[Built2Bend]

Did the copper line you've seen fail have a steel inner? I would think with the steel inner it would be plenty strong enough.

[rlrnr53]

I've never seen a copper line with a steel liner in it, the only other thing I've seen has been a double strength copper, but it too fatigues fairly quickly.

[HenryJ]

All the talk of rusting brake lines reminds me that brake fluid is hygroscopic. It has an affinity for water. Change it. More frequently if you live in a climate with high humidity. The fluid loses its hydraulic properties and leads to internal degradation.

[Diverdmt]

I know this isn't the right section, but I have 2 ZR2's Im parting out. I have a black crew cab and going to put one set under it and sell the other set. Looking at 2 body lift and inch suspension lift. It don't see much offroad I have a solid axle V suercharged truck for that with 38's. So anyone here dones the ZR2 rear axle swap then?

[HenryJ]

Easy bolt on improvement for the crew cab Big improvement over the flexy stock housing

[Horsehammerr]

I would go with a rear from ZR2. The 8.5" rear is wider to match the track of the front without spacers. Disc brakes and ABS sensor to match the braking system. Good availability of parts. Eaton G80 gov-loc and gears to match mine. Lots of aftermarket support. Requires less horsepower to operate than other options, other than stock.
You would lose some ground clearance due to the larger center section. That may be a good reason to stick with the stock 7.625" diff. I have invested in a good cover, rotors and pads for that rear end, so I am in no hurry to switch.

How much bigger is the center section than stock ? Is it only like an inch in diameter ?

[Horsehammerr]

Got my '03 ZR2 rear axle assembly yesterday. Came with everything but the Calipers. Does the Panerd bar bracket need to be removed or can you just leave it alone and bolt up ? I ask because the right side brake line is attached to that bracket. Will this bracket clear all under our CC's ?

[Ezrollin]

.........then the rear from any 5-speed S-series should be the 8.5" and you can get a set of 1.25" spacers.

Are you sure of this? This is the first that I have heard this but, you may be absolutely correct.

No, not all 5 speed S-series had 8.5 rear-ends.

[Horsehammerr]

Got my '03 ZR2 rear axle assembly yesterday. Came with everything but the Calipers. Does the Panerd bar bracket need to be removed or can you just leave it alone and bolt up ? I ask because the right side brake line is attached to that bracket. Will this bracket clear all under our CC's ?

Did not have to modify anything on the ZR2 rearend. Only mod. I had to do was set the whole thing back 1 3/4" so my drive shaft would have the 3/4" play it needs at the Transfer Case. Stock position had the shaft jambed tight with no free play for up and down travel. Probably created this problem in lowering. WORKS GREAT

[southernzr5]

how did you set the axle back? any pics?