I have some of this in another thread but I want to keep this one a little more simple.
I started this project because I suspected a leak from the rear diff and thought I would remove it to re-seal the cover. Well, the " while I'm here I may as well...." bug bit me again. I drained the fluid and I got 56 oz out, so I don't think it was leaking. I decided to change the axle shaft seals and also the pinion seal mainly because of their age. I initially thought about replacing the bearings also so I removed the center from the case and the bearings all look good.
After doing some looking around, I found that as long as I did not change anything internally that I should be able to put everything back togeather with the shims as they were.
Is this correct?

 

I was once a GM dealer tech and have serviced and replaced lots of internal parts on axels, but never on a C4 corvette, I own a 90 6 spd coup and restored everything
I removed my unit from the Bat wing and sent it too Zip corvette for complete over haul and 4:11 gears up grade i didnt have the tools for working on it. you must retorque the pinion bearing nut to the same amount as was before it was removed, simply marking relationship of pinion nut to case is fine the left side side bearing shims are for backlash and the right shims are for total preload put them back as removed and you'll be fine, while its apart you can get a drain plug kit from Zip corvette and if your handy with a drill and tap have a drain plug, kit comes with a template for drilling.

 

vettespecial, I did not mark the pinion nut before removing it nor did I check the torque or count threads. I was under the impression that since there is no crush sleeve but only shims that wasn'relevant as long as you put it back with the same shims all the way around. I did get a new Pinion nut and washer. I have heard that when putting it back togeather that using hylomar on the seals and the pinion shaft splines is a good idea. Have you heard of this?

 

New pinion nut and washer was a wise buy. You need to check the differential shaft (#23) in the carrier for fit because if it's still apart it's easy. Clutches? Here we would always replace the 'pinion thrust washers', regardless of the rear when doing regular maintenance it's always been a 'to do' that I was told 'to do'. You'll NOT find it in print but a very good builder did this always. In this image they're #25. If the shaft is a poor fit to the case then it certainly becomes more expensive.

The Dana/Spicer part # is 13338-3 and they're inexpensive. A CMC/Jeep dealer likely has them in stock 'local'. A talented parts guy should have no issue. I've bought these often from a 'local' FoMoCo dealer. Somewhere I probably either have a few or part #'s for FoMoCo or CMC/Jeep.

**** Do you have access to the proper 'spreader' to do the reassembly of carrier to the actual housing?

 

WVZR, I was hoping you would respond to this thread. I hear that you know your 'stuff' on the Dana rears and was hoping that this wasn't going to turn into a can of worms.
Let me reiterate.......
1. The car only has 40,000 miles on it but I wanted to replace the suspension bushings, because of their age, with the Superpro bushings. The diff had to come out in order to replace the batwing bushings, and once it was out, the buildup of oil/grease on the bottom of the carrier had me thinking that there may be a leak and that now would be a good time to re-seal the carrier/cover.
2. At no time did I suspect anything wrong with the rearend of thiis thing, but I did know that now would be a good time to install new seals in the carrier, again because of the age of the car. Well, this is where curiosity crept in and I decided to at least inspect the bearings and races and so I removed the case and found all bearings and races to look really good.

I've been doing my research and visited this forum for advice, before and during this process. My understanding is that as long as nothing was changed inside the case, that I should be able to change the seals and button it back up without having to worry about anything changing from where it was before taking it apart. I was able to find the J-35511 and J-35503 seal installers dirt cheap to make installing the seals idiot-proof.

So, here I am, with the proverbial opened can of worms on my bench. The only thing I was planning on doing before closing the thing up was to check the gear tooth contact pattern.
Anything more would require me to send it to a tech and then watch my wallet get thinner and thinner. To change those thrust washers would require the J-34174 tool and I definitely don't have that.

 

40K miles - seals just because you're there is likely fine. I know someone that would say it 'ain't' but he's unfortunately no longer with us.

How did you remove the 'carrier' from the housing? How do you intend to get carrier back into the housing?

 

I used a long breaker bar handle and it came out relatively easy. I had been asking if this could be removed without a spreader but no-one replied to that. Through my research I had seen that it was not absolutely necessary. I will be using a 2lb dead blow hammer. And I was going to use Permatex 51031 high temp anaerobic lange sealant on the seals and had also seen where some say to also apply this to the splines of the pinion shaft to avoid any possibility oil leaking through that area

 

???????

GM# 12345879 Grease for the pinion splines and also for the transmission slip-yoke. You only need a 'swipe' of it so if you know a GM Tech they've probably got can of it on their bench OR someone in the shop has.

 

Ok, so now you got me worried, WVZR. I'm sorry I just saw your question Do you have access to the proper 'spreader' to do the reassembly of carrier to the actual housing? in post #4. I do not have access to a spreader. So then without the spreader, I can damage something or does it just make the job easier?
Since I don't have the tool used to replace the thrust washers, and I don't have a spreader, you think I should take it somewhere to have that done and have the carrier installed by them also?

 

I haven't done this job, but I bet you could get it done w/o a spreader.

Put the case in the oven, carrier in the freezer....then put 'em together quick!

 

I'd ask local and have a 'conversation' with someone. It actually might be good to have the thoughts of someone who has done the builds. 40K maybe just disregard the thrust washers but having a spreader to drop the carrier into the housing would be good. Do you know anyone that maybe has a 'relationship' with a dealer Jeep/CMC, GM or others? Ask a 'local' speed shop or performance parts reseller if they could recommend a builder for rears, you're looking for a conversation NOT a several hundred $$$ install. Rent/borrow a spreader?

Your stuff is pretty damn clean - seems maybe foolish to short the job at this point - a 'conversation/help' from someone seems pretty damn reasonable at this point.

https://www.corvetteforum.com/forums...post1605293127

You're pretty close to several people that might be able to direct you. The 'FBI' (Fast Boys of Illinois) a group of ZR-1 owners etc in the Naperville, Chicago, Bartlett area. PM @Paul Workman or maybe @-=Jeff=- and ask for a referral to someone that might be willing to help. They have 'Pizza Night' pretty regular.

***Check 'The Yellow Pages' for maybe a Spicer Driveline shop in the area.

 

Well, not having a whole lot of help finding someone to help with this.
1. I contacted a local Chevrolet dealership that has been around since the 60's and who's owner has always been involved with Corvettes. Their mechanic tells me that since the fire that destroyed the business several years ago, they no longer have a case spreader and tells me they can not do anything for me. I think he just blew me off.
2.I contacted one of the persons WVZR-1 recommended and he got me in touch with someone in Addison, Illinois that has told me he has a spreader and if I stop by his shop, he will install the carrier into the case and I could finish reassembly. He is 180 miles away from me.
3. I contacted someone in Peoria, right up the street from me, who was recommended as someone that knows what he's doing and he says that he will install the carrier and set it up for $150.00. When I mentioned the spreader he says that he can do it without it.

Other than that, the other contacts I have made run like I have the virus as soon as I mention the word Corvette.

 

Well - I'd sell a 'spreader' and disassembled I believe it would ship in a USPS 'Large' box. It's damn heavy but I don't know of any weight restrictions. I understand that if it fits 'it ships'. I have adapters but the last time I loaned a pair they didn't come home. I'd probably loan this pair but require a substantial deposit and you pay the ship back.

There's *** spreaders on eBay 2 hours from you that are available for 'offer' !!! How much? No idea - would I compete? Don't know but I won't pay the ship. Does the eBay guy have the adapters? Don't know!

*** I might be reluctant to do the eBay 'offer' spreaders. They very well could be something other than the actual advertised 24385 Kent-Moore or

*** The spreader I have that I'd sell is a J-24385-B and I don't believe that the bar even in the narrow position will do 'vette/Viper aluminum housing. Don't have a housing close enough to confirm.

 

I have the adapters, I found them on ebay for $37.00

 

It is easier to service with a speader, but can be done without one. Used bearings is fairly easy with patience. Start it square block of wood and a hammer. Tap until it's in place. New bearings will be more difficult. Hopefully you measured backlash, you will need shim kits to set backlash to original number. Along with bearing preload, you will need an inch pound torque to measure rotating torque. A fish scale can also be used. Dealing the housing imo is the biggest hassle with nothing to keep from moving.

 

I am trying not to overthink this but I really would like to complete this job myself if I can. With that being said:
I pulled this diff out of the car for two reasons; I wanted to re-seal it because I suspected a leak and I wanted to install Super Pro bushings in the batwing. There was nothing wrong with the way the car ran and there was no noise from the rear. So the rearend DID NOT NEED to be seviced in any way. I cleaned the diff and installed the bushings.
When I thought about how much effort it took to get the thing out of the car, I came to the conclusion that changing all u-joints would be a good idea, so I changed them. I have a press so that was not a bad job. I also put a lot of elbow grease into cleaning everyting as I went. I have got the complete rear suspension off of the car sitting on tables and benches and looking all nice and "purty" just waiting to be installed. So far everything about this job has been grunt work and not a big deal.
I decide that changing the seals in the diff seamed like a good preventive maintenance move also, considering the age of the car. I removed the pinion yoke and pulled both axle shaft yokes in order to change the seals.

Here is where my dilemma begins:

I could have changed the seals, re-installed the axle shaft yokes and the pinion yoke, re-torqued the pinion nut to 200 ft lbs, re-sealed the batwing to the case, and filled it with oil, and called it a day. In like flint...correct?
But nooooooooooooo, out of curiosity or just wanting to confirm there was no problems there, I have to inspect the bearings and races. So I pop the center out of the diff to do so and apparently this is where it all becomes rocket science.

I did quite a bit of research and asked around for advice and opinions and it is my understanding that as long as nothing has been changed or replaced inside the diff that I should be able to button it back up without having to worry about anything changing from where it was before taking it apart. Is this correct or not? If it is correct, then if I did decide to change the bearings also, couldn't I use the same shims as they are and button it back up without having to worry about anything changing from where it was before taking it apart.?

The only thing I was planning on doing before closing the thing up was to check the gear tooth contact pattern just out of my own curiosity..

 

WVZR-1, that spreader that you had mentioned finally got here today and it will work with the adapters I got.
I decided to bite the bullet and have someone setup the rearend for me. He tells me he will do it for $400.00. This guy is known by a lot as being the guy you want to see. I was told that he only does bench jobs now and that he does the work in a shed in his back yard. When I got there with the parts, he came out with a wheeled cart and wheeled it into his shed, I was pretty confident that I have found someone that has the experience. The tools and misc parts hanging in there was amazing. He says some of the stuff has been in there over 30 years. We'll see.

 

I got the diff back yesterday and he tells me he is happy with how it went. He also tells me that he thinks the gears probably have 100K miles on them but that he sees nothing wrong with them. In our initial conversation, I had told him that the car had 40K on it and that the only reason I had the diff out of the car was to re-seal it because I suspected a leak and I wanted to install Super Pro bushings in the batwing. I told him here was nothing wrong with the way the car ran and there was no noise from the rear.
I know someone has been in the diff at some time because one of the mounting holes for the batwing has a heli-coil in it.

So now I have absolutely no idea of what I got here. I assumed the car had 40K because that is what the odometer showed. The fact that the car had been sitting in a New York city parking garage from 1989 until being purchased in 2014, and then sitting from 2014 until the time I won it in that sweepstakes in 2019 also reinforced my belief that it was a 40K car. I have no idea why someone would be replacing a ring and pinion on a 40K car with the same ratio it cane with. I wish there was a way I could track down some of the car's history. ANy ideas on this?

OK, back to where I stand with putting this thing back together. I have all new SuperPro bushings installed in the rear and I purchased the C-beam plates from Bill @ zfdoc and am going to use those along with the 3M 08609 Window-Weld urethane. (You only have about 15 minutes working time with this stuff). I have the rear of the transmission overdrive supported with a floor jack and the C-beam is still attached at that point. The car is sitting on Quickjacks.
I am also going to be replacing the complete exhaust system from the manifolds back to the mufflers but at this time the front Y-pipe with the converters and the rear Y-pipe are still on backorder.
Stay with me.........

So, at this time

1. I am going to install the diff to the C-beam with the C-beam plates minus the 3M Window -Weld and minus the drive-shaft.
2. I am going to install the rest of the rear suspension and get the tires back on the car so that I can get the car on wheel cribs instead of the Quickjacks.

Let me explain my rationale concerning the wheel cribs. I am a carpenter, not a mechanic You can put me a hundred feet in the air, I have no problem. But, put me under a car that is suspended off the floor and I am NOT in my comfort zone. Having said that, I will do what is absolutely necessary to complete the rear suspension but will complete the remaining work with the car on the cribs.
.

These things are screwed and glued and are 20 x 14 and 11 inches tall. I will be comfortable completeing the following with the car on these.

1. Remove the remaing exhaust.
2. With the transmission supported with a floor jack, disconnect C-beam fom diff and tranny and remove from car. Also be able to clean it up
3. Do a little cleaning and detailing of the tunnel area and floor pans.
4. Replace the rear output shaft oil seal on the overdrive. (Timken # 9613S) I am told this is the correct one.
5. Change the gear oil in the manual transmission with Red Line MT-90 75W-90.
6. Change the fluid and filter on the Doug Nash 4+3 Overdrive (Valvoline Dexron-VI full synthetic ATF).
7. Install C-beam with the C-beam plates and the 3M Window -Weld.
8. Install drive-shaft.
9. Get rear wheel alignment and tire balance.

This winter I will be rebuilding the front suspension and will get that alignment when that is complete.

I would appreciate any input anyone has concerning this.

Thanks
Kenny