[V Wagon]

I took apart my diff this week. All the part numbers are confirmed with what is stamped on the bearings with exception of the front pinion bearing. It's got a whole bunch of numbers and letters on it that don't match any part numbers. GM used all SKF bearings on these units.

What are the numbers on the bearing that didn't line up? Does searching them lead to any revelations on what they might be that is different from what I had come up with based on dimensions?

 

[walkers4x4@yahoo.com]

The front pinion bearing had the following markings on it
SKF BRAZIL 6W32F R6T1-0382/Q
The race was marked with the same but had 6W33E.
I bought a Timken HM802048 and it is the same dimensions. The tapered needle bearings themselves are a little smaller on the Timken bearing than the SKF. But the external dimensions are all the same.

Taking this thing apart was difficult. The flanges that the axles bolt to have a splined axle on the other side. The spline side of the axle flange is held in the limited slip carrier by c-clips. They are a pain to pry off without having special tools and a press. Once you can get the axle flanges out. The carrier with the ring gear comes off easily. The pinion needs to be pressed out. I beat on it with a dead blow hammer and it eventually came out. You'll need a bearing puller for the carrier bearings and the rear pinion bearing. The races seemed like they would be impossible to get out but then I saw a video online that said to weld on the face of the race. The race would shrink and it would fall right out. I used a TIG welder with no filler rod to eliminate sparks and spatter and it is definitely true. The races would fall right out when I flipped the diff over.

The carrier had 1 shim on the passenger side behind the pressed on bearing. The pinion had two shims behind the rear bearing that were showing wear from moving. My guess is that my pinion bearings got no oil going up the steep incline, got hot, expanded and started to sieze. This wore away at the shims and ground then down. The pinion was then freed and backed out and started making contact on the toe of the ring gear, causing all the damage. All bearings showed a little sign of wear but the front bearing definitely had it worst. The front pinion bearing gets oil through a 1/4 in hole at the bottom of the casting. This hole is partially blocked by the race so the pinion bearings don't get much lube. The 75W-90 must become like water at those temps. I have changed the fluid multiple times on the diff and there is always a vacuum as I pull the check plug out. The breather is definitely not doing its job an something funky is going on. I am probably going to overfill next time and try and go with a thicker gear oil.

I am going to rebuild my old diff and try and get a good gear mesh. The toe of the pinion and ring are worn but that area should not be making contact with a good mesh.

I bought a shim kit that seems to be the correct size for the pinion bearings. I will post the part number if it's a good fit when it comes in.

Hopefully, this helps someone and gives them the motivation to tear their own apart.

 

[walkers4x4]

I finished the rebuild today. I am going to swap the diff in the coming days and see how good my work was. I drilled out the oil passages to provide more oil to the pinion bearing. I took out the stock breather and replaced it with a hose and check valve.

I used Motive Gear 1105 shim pack for the pinion bearing. There wasn’t a large variety of different size shims but enough to get the spacing I needed. I could never find a good shim pack for the carrier bearings. I ended up using the stock set as there would be no easy way to pull the races each time to make adjustment. Plus the case is closed in so you cannot measure backlash.

Lessons learned:
Do your best to save the old pinion bearings and keep them in good condition if they aren’t completely shot. You will need to grind down the inside of the old bearings with a Dremel so you can slide them on and off the pinion when using the marking compound to check the mesh.

Heat from a torch and dry ice are your friends when trying to get the bearings and races installed.

I ended up having to use a large 1 in thick piece of solid steel bridged across the inner pinion bearing and a sledgehammer to finally get it to seat.

Save all your old races even if you used the welding method to remove them. You will need them for hammering or pressing on while installing the new ones.

Overall it was like 200 bucks in parts to replace everything in the diff besides the ring and pinion and the limited slip carrier.
Carrier bearings: Timken 32010X (need 2) comes with races $22 each
Inner pinion bearing: Timken HM903249 $37
Inner pinion race: Timken HM903210 $21
Outer pinion bearing: Timken HM80204 $17
Outer pinion race: Timken HM802011 $5
Axle seals: AC Delco 291-341 (need 2) $6 each or GM 25995847
Pinion seal: AC Delco 25861283 $35
Pinion shim kit: Motive Gear 1105 $24
Gear marking compound $8

Ring gear is 9.5 in btw. Pinion is totally unique to this car from what I could find. If someone was motivated enough they could send their old ring and pinion into a gear company and have a custom set cut.

 

[random84]

Bravo!





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[bmylez]

This needs to get stickied.

 

[NRNG759]

Walkers4X4 did you use a dial indicator to set the lash or kept watching for the desired 'smear' an the R&P???
Big thanks for birddogging all those #'s....

 

[walkers4x4]

Walkers4X4 did you use a dial indicator to set the lash or kept watching for the desired 'smear' an the R&P???
Big thanks for birddogging all those #'s....

I tried to get a dial indicator in through the drain plug to check backlash but I couldn’t reach the ring gear. Plus the teeth of the gear are on the other side. This design sucks with the whole unit sandwiching together. I kept checking the mesh with marking compound and changing the shims on the pinion.

I reinstalled the diff yesterday but it appears my ring and pinion were too far gone. The high pitched whine under load was still there. Talk about defeat after 7 hours under this thing in the heat, plus I’m gonna have to pull it again. So if you see any abnormal wear on your ring and pinion it is shot and not worth the effort. I am gonna break open the other diff I have and see if I can see any obvious wear or failure. This one makes noise all the time so it might have a better shot of being a bad bearing.

 

[walkers4x4]

Second diff has a bad carrier bearing which makes sense because this one makes noise all the time. Good thing the carrier bearings are a lot cheaper and easier to install. I will repost what the results are from this diff rebuild.

 

[bmylez]

Can you post pictures of your worn ring & pinion? Even if they make noise, are they really going to fail that quickly if they have fresh bearings?

 

[walkers4x4]

I can't post pics because I don't have enough posts but you aren't missing much. The heel of the ring and the toe of the pinion have rough grinding on them. The face of the ring and pinion are both shiny polished surfaces and this is rough cuts at the ends of the gears. I'm gonna check the mesh again on it to see if something shifted after it was assembled in the car.

In my opinion the diff can make the types of noises.
1. Clnking or chattering particularly while making turns. This is caused by the limited slip failing or just not having the correct gear oil with the additive in it.
2. Low hum noise that is around all the time. It gets louder with speed but stays the same pitch. It is also always there whenever the wheels are turning.
3. High pitched gear whine. This is the ring and pinion not marrying up correctly. Can happen during acceleration, or deceleration.

My bad diff with the high pitched gear whine is so loud it sounds like there is a jet engine starting when you accelerate or are under load. It is so loud that it high pitch rattles things in the door and makes it feel like your fillings might fall out. This is not the picky " this thing is making a little noise and it shouldn't because it's a Cadillac". This is holy crap the gears are chewing themselves apart. I drove it this way for two months while trying to find a replacement and the damage was evident. I believe the diff would eventually fail with chipped teeth if I put another 10000 miles on it or pushed it really hard up hill.

Diff swap is coming this Saturday. I will let you guys know how stuff goes. If you really want pictures let me know and I'll figure out a way for you to see them.

 

[random84]

Open up an imgur account and post the image URLs. Very easy.

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[bmylez]

In my opinion the diff can make the types of noises.
1. Clnking or chattering particularly while making turns. This is caused by the limited slip failing or just not having the correct gear oil with the additive in it.
2. Low hum noise that is around all the time. It gets louder with speed but stays the same pitch. It is also always there whenever the wheels are turning.
3. High pitched gear whine. This is the ring and pinion not marrying up correctly. Can happen during acceleration, or deceleration.

My bad diff with the high pitched gear whine is so loud it sounds like there is a jet engine starting when you accelerate or are under load. It is so loud that it high pitch rattles things in the door and makes it feel like your fillings might fall out. This is not the picky " this thing is making a little noise and it shouldn't because it's a Cadillac". This is holy crap the gears are chewing themselves apart. I drove it this way for two months while trying to find a replacement and the damage was evident. I believe the diff would eventually fail with chipped teeth if I put another 10000 miles on it or pushed it really hard up hill.

Ok yeah, I would definitely have pulled my diff at that point, too. The whine that mine makes under acceleration is only a little noticeable, and I can barely hear it over my stock mufflers, so it sounds like I am way waaaay off from where you are right now. Still, this info is awesome and I probably won't be holding onto my Ford 8.8 as a possible solution, haha.

 

[walkers4x4]

http://s545.photobucket.com/user/walkers4x4/library/

 

[walkers4x4]

UPDATE
Replacing the carrier bearings only made the noise worse. From this experience I believe that most all noise is coming from the gear mesh. I didn’t check the pattern on this one but I am guessing it is off. My hypothesis is that the gear sets are getting too hot and softening, resulting in noise that progressively gets worse.

The gear set appears to match GM 10 bolt 8.5 inch sets. I can’t find any schematics for the pinion of a GM 8.5in so I am going to order one off of amazon and see if it is a match. The 8.5in sets come in both the 3.73 and 3.23 so that is good. I think the ring is going to be easy to find but the pinion might be a needle in a haystack.

 

[t.j.t]

Love the dedication with this.

 

[V Wagon]

What's the most recent thing that came with an 8.5 that I could use to compare dimensions to the V ring and pinion? If I can find math data of an 8.5 I can save you some buying of things that might not work.

 

[V Wagon]

What about this? Seems more likely to be a match than a GM ring and pinion since it is a Getrag diff.

https://www.usgear.com/products/ring-and-pinion/chrysler-8-7-irs-3-23-ratio

Shit, that says pinion shaft diameter of 1.876 and I measure 1.75 on the V diff in math. Seem like something else has to come with the same Getrag diff and have serviceable internals. 8.7 does match the ring gear OD though. So, still in the boat of the ring gear being findable but the pinion being unobtanium.

 

[walkers4x4]

GM used the 8.5 inch 10bolt in a lot of their light duty trucks and suvs throughout the years. The pinion is definitely the long pole in the tent. The ring looks like any old ring gear. The pinion is not your regular black steel finish. It has more of a light grey appearance. It has a big relief hole drilled through the center of it and it uses a solid spacer vice a crush sleeve which is rarer.

I plan on buying a set off amazon and I will return it if it isn’t a match. I haven’t seen a new diff online besides eBay and the asking price was 3250! I will never be able to sell the car this way with how much noise it’s making. Plus, lesson learned, used diffs online most likely make noise unless it was off a low mile wreck.

 

[walkers4x4]

https://www.yukongear.com/diffdetai...chMode=Diff&TypeID=5&Type=GM&DiffID=218&DiffName=GM+8.6%22+Rear%2c+%2709+%26+up

09 and up 8.6in 10 bolt 30 spline axles...could be...

 

[V Wagon]

I think you're still going to be closer with the 8.7 Chrysler gears. I guess I'm not sure if you were an auto or manual. The 3.23 gears are available aftermarket. the 3.73 gears are an OE gear for them and I can't find them aftermarket, don't know if Chrysler sells the gear separate from a diff if you are in need of the manual ratio. The Chrysler diff is a Getrag as is the V. 8.7" = 221 mm and that's what the ring gear in the V diff measures in math data. The V pinion in math looks similar to the Chrysler pinion in pictures. But as I mentioned, US Gear says the Chrysler pinion shaft is 1.876 and the V one in math measure 1.75.