I have a buddy who has a third gen and his posi is now a full time one wheel peel.......the GM dealership told him its going to be $800 in labor and $900 for a new differential......this sounds very high to us.....is that about right or can he have this done somewhere else for alot cheaper? His car is a 91 Z28 if it matters. Also.....is the car safe to drive this way? Thanks

I think the term Highway Robbery really sums that up.

A brand new Eaton differential is about $375
New Yukon ring & pinion is about $165
All the bearings, set up parts, etc. are $100
New axel bearings & seals are about $50
New Moser axels are $250 a pair

Labor should run about $300-$400 tops. I know guys who do rears all day long for $250.

Either the dealership doesn't do many rears, or is just blatantly trying to rip you off.

wow......thanks for the input. I appreciate it....

You could even buy a complete 4th gen rear with disk brakes, 3.42/3.23 posi for $300 or $400. You would just have to look into different wheels. Randy's ring and pinion sells cheap rebuild kits as well and you can get a take out 4th gen posi for under $100. Any competant shop should be able to rebuild your rear for $300 or less if you supply the parts.

I will second Randy's Ring & Pinion. I use them exclusively now for rearend parts. Prices are the best around, quality is first rate, and the service is excellent. www.ringpinion.com

thanks everybody for the help......can a differential (being what is broken) be replaced without having to change everything else? A dealership told my buddy that everything should be changed....is that true or BS? Also, the axles do need to be pulled to swap out the diff right?

Strictly speaking no. You can change the differential and re-use everything else.

The thing is that if you've got a rear in a 3rd gen it is at least 13 years old. A lot of these cars have been driven hard and put away wet so to speak. If the differential is shot, chances are that everything else is on its way out too. 7.5" 10-bolts aren't exactly know for gearset longevity. The type of use and abuse that would ruin a differential is the same type that will ruin a gearset. Even if the gears look okay they may have stress cracks that you can't see. Eventually this will lead to failure and having to open the rear back up. It could also lead to damaging the new differential that you just installed. If you're going to the trouble of replacing the gears anyway you really should do all the bearings and races too. The particles from the burnt up clutchs in the differential and the fact that the oil was probably never changed means that the bearings are probably used up too.

Yes, you do need to at least pull the axels back some to change the differential. I would do axels bearings and seals too at the least. Inspect the axel shafts closely, particularly where they ride on the bearings, and at the end that takes the c-clip. Replace the shafts if you see cracks, or galling (places where metal has been pulled off the shaft) on the bearing seating surface. Re-using damaged shafts is false economy. If you break an axel shaft it will lead to more severe damage, including causing you to get in a wreck that would total the car, and possibly hurt or kill you. Not the type of chance I'm comfortable taking.