I have an 04' Grand Cherokee. I just hit 205k miles. Most of the mileage is highway miles. In October 2010, I had new brakes pads & rotors replaced all the way around. New shocks, and I had the rear wheel seals & bearings and fresh differential fluid. The bearings & seals portion of my bill, parts & larbor was $475.00 All completed by well know national auto service company. In Jan 2011 I noticed that I had fluid all over my rear passanger side tire and as well as the back of the truck. I took it back to the shop. They made the repair at no charge, but apparently the "new" rear seal was leaking. Yesterday I broke down which was 2 months later. The truck lost acceleration on the same rear wheel( passenger side). started whistling, burning smell, then started into a grinding noise by the time I was able to turn into a gas station. later was towed to the auto shop. Same national company that did the original work, but different location. Come to find out there was only about 4-5 oz of differential fluid and metal shavings. and definitely no leaks! Obviously extremely low! This mechanic believes that no fluid was added after the apparent leak in January. He also says that the pinion bearing that goes into the yolk has too much play. I confirmed that it does have a little but what is too much?
They offered me a so called deal to resolve this because they feel partially responsible for the lack of differential fluid, however due to the pinion bearing, and total mileage they say the rear axle was could have beeb going bad anyway. There proposal is- I purchase a "used" rear end Approx $700+ taxes (not sure what else yet will be priced in.) They will do the installation at no charge, and I asked to pay for my rental car for the week which will be $350 to $450. And they may provide some kind of warranty.
After all said and done, I will probably have spend $1300 to $1500 on a problem that may or may not have been caused by the repair shop. I really think I am getting a bad deal, but the whole situation is a catch 22.
If I get greedy they may just change their mind and refuse correcting the problem. Then I still have to get a new"used rear end" and pay for labor and hire an attorney.

Question 1) Did having barely any fluid cause this entire problem?
2) Should they be responsible for the replacement purchasing another rear end or am I stuck because of the age & mileage etc...

Any input, ideas, thoughts and opinions will be greatly appreciated!!

 

1) 99% probability, if it is as you described, yes. The low oil level did not allow proper lubrication of the rear end bearings causing them to overheat, and spall out.

2) They should be, but you'll probably have to get a lawyer and mechanical engineer involved. Rolling element bearings DO have a finite life, called the L10. It is calculated if you know the load, speed and bearing type. If you are below the L10 limit on the rear end bearings, the only applicable failure mode would be the lack of lubrication. (L10 refers to the point at which 10% of a given sample would have failed.)

If it is a decent shop, they'd know they frigged it up and take care of it. If they're already giving you BS, I say you're in for a lot of pain.

 

Welcome to CF.
I say it's their fault and their responsibility to fix it.
If you did have to pay for it you could find a replacement WJ D35 for $200-400, and get someone to install it in a few hours. JMO

 

U go in there u tell them I originally paid u to replace these seals n bearings n service the diff. The first u replaced was done WRONG I cane back in u fixed BUT h did NOT refill the diff which is completely YOUR fault so now ur gonna fix it all because j originally came to u for the fixes n u messed up worse than it was wen j first came in!!! Then tell them u have already spoken to an attorney if this is going to b a problem!