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Hey guys,
I have a 1987 442 that needs a new rear differential. I don't know much about cars but I love this one. I took it to my mechanic and he wants 3000 to rebuild it. This seems steep to me. I have no idea where to find a differential for this car or if it is compatible with a differential from another car. I have had no luck so far and I am hoping that someone on here could point me in the right direction. I can provide more information on the car if needed. Thanks in advance!
Well it should have the 8.5... BUT you should first post pictures of the rear end cover area so we can ID the rear end size.
Then we should need to know what happened to the rear?
What went bad?
3000.00 IS WAY HIGH. Unless he is replacing the housing too.
I sell a BRAND NEW Moser 12 bolt for your car for 2400.00 so where in gods name is he coming up with 3000.00???
You could probably ship me the rear and I could rebuild it and ship it back for less. LOL!!! Jim
I can take pictures this weekend, maybe tomorrow. TBH I don't know what specifically is wrong with it. The mechanic just said it needs to be rebuilt, I could call and ask tomorrow as well. Thanks for the quick reply.
That is the 8.5 rear, only '84 H/Os,85 up 442s & the turbo Buicks used them in the G-bodys, very desirable & hard to find rear ends. Most G-bodys came with the weak 7.5 rear. What's wrong with yours, is it noisy??? Maybe it just needs axle bearings? They are very easy to get parts for. Like Monzaz said $3k seems very high! Complete rebuild kits(bearings, shims, crush sleeve, etc) aren't that much, usually around $100-$125. The clutch plate kits for the posi are around $100 -$200. I'd find another mechanic!
That sounds like the i dont want to do it but i will for the right price, price.
Yep, I do that with truck front diffs on the independent GM truck...lol.
Can not say I have never done the over price cause I really do not want to do it deal....lol.
CLUTCHES...If the rear needs clutches there are no GM ones anymore. They are all gone now.
We have some aftermarket kits but they are up there in price now only so many are made per year and after the cost of replacing labor and the clutches and ship[ping Best to just buy new anymore. 200.00 plus for the clutches I have about 5-6 sets here for the square tab 8.5 trac lock posi units with the 'S' spring
Here are a couple pics. I did what I could, but let me know if I need to try and get something different of a scale is needed. The mechanic never actually pinointed the problem it turns out. To me it sounds like a bearing maybe. The sound is low and grindy and only audible at low speed(usually turning) or in reverse.
That is the 8.5 rear, only '84 H/Os,85 up 442s & the turbo Buicks used them in the G-bodys, very desirable & hard to find rear ends.
Yes, NMolds the pictures you provided indicate that it is in fact an 8.5. The triangular tabs opposite each other on the bottom of center housing are a tell-tale sign.
Everything Rob said above is dead on. These are fantastic differentials known for being durable.
Originally Posted by NMolds
The sound is low and grindy and only audible at low speed(usually turning) or in reverse.
I would get a second opinion from another shop at a minimum. Being as vague as possible with the issues when you try to give them an idea of what you feel is wrong. Literally wouldn't say anymore than what you described above.
Yes, NMolds the pictures you provided indicate that it is in fact an 8.5. The triangular tabs opposite each other on the bottom of center housing are a tell-tale sign.
Everything Rob said above is dead on. These are fantastic differentials known for being durable.
I would get a second opinion from another shop at a minimum. Being as vague as possible with the issues when you try to give them an idea of what you feel is wrong. Literally wouldn't say anymore than what you described above.
You could replace the carrier, gearsets, axles, etc and have most of that 3000 still in your pocket!! Find another shop, as stated earlier you can get a complete ready in install rearend for slot less than 3000.
I will get a second opinion, but I have had terrible luck with mechanics in my area. I have lived here since 2012 and have not found one I like. There has only been one mechanic I have gone back to, but they proved to be less than honest as well. I don't have a lot of hope about this.
Well, my experience (and this is only MY experience, others may have had different experiences) with rearends has been that the axle bearings are the most likely to go bad. The carrier and pinion bearings are swimming in oil so they are more likely to remain oiled even if the oil level is low, whereas the axle bearings out at the ends of the tubes are easier to get deprived of oil.
I will get a second opinion, but I have had terrible luck with mechanics in my area. I have lived here since 2012 and have not found one I like. There has only been one mechanic I have gone back to, but they proved to be less than honest as well. I don't have a lot of hope about this.
I will get a second opinion, but I have had terrible luck with mechanics in my area. I have lived here since 2012 and have not found one I like. There has only been one mechanic I have gone back to, but they proved to be less than honest as well. I don't have a lot of hope about this.
Hang in there bud. Don't let this get to you, getting a second or third opinion without telling them you think its the differential is key.
I have a rough but well running 87 442. Lots of track time, never an issue with the rear or entire power-train for that matter. Car proved quicker than my 69 so far. We are talking well over 100,000 miles. I don't see your differential getting damaged with the stock power-train unless abused and or neglected and even then I have my doubts. Now maybe it is the differential but I would look everywhere else first.
As far as an honest mechanic being hard to find goes, its true. When a decent mechanic is that hard to find do your best to pin point the issue yourself if possible. Maybe have a friend stand on the sidewalk as you slowly drive back and forth on a quite street, etc. Car issues can be funny at times, what sounds like its coming from one place may be another place. Check all your fluids, including differential. When is the last time you had everything lubed... What you are describing does sound like a bad bearing pack needs replacing which by itself represents a small fraction of the price you were quoted.... Maybe try to strike up a conversation with older guys with similar cars who may have a good and reasonable mechanic they can put you onto.
P.S. I know plenty of this may sound silly but the point I am trying to make is. Our cars seldom have major problems and often have silly little problems that we turn from a molehill into a mountain, in our minds. I would be as sure as you can be before getting stressed out over anything.
IMHO that is way too much to rebuild your rear end. I have one that was completely rebuilt and had it for sale for $1200 for months on G-body site. The only interest was if I would ship it. I would not ship under any circumstances, so I kept it under the car and continue working on getting the car together.
June 19th, 2020, 09:31 PM
