: Differential Questions



smythcounty
05-20-08, 09:48 PM
Ok I had the differential fluid changed in the front and rear on my '03 today. The mechanic had to go to the dealership to get the fluid and they told him to put the synthetic fluid in the rear 3(3 qts $95) and the regular "grease" as he called in in the front. They told him that the synthetic had been eating up the bearings in the front Any of you guys heard this one?

hcvone
05-21-08, 09:26 AM
That is bull, they have been putting synthetic gear oil in for a few years now from the factory, Corvette's starting doing it in 99', I have put synthetic gear oil in all my Suburban's since 89'. The front bearings have been being eaten up by not using synthetic gear oil, the heat causes the bearings to fail, synthetic oils protect to many hundreds of degree more than standard oil does. The dealerships used to say the same thing about synthetic oil in the engines, now all Caddies come with synthetic oil in the engines. :)

smythcounty
05-21-08, 11:22 AM
So I guess when I change the next time I'll just get the fluid myself. I thought that was kind of strange especially after reading on here about the synthetic suggestions...How long would you run the regular in the front before changing it to synthetic?

hcvone
05-21-08, 12:47 PM
The front is easy to change, I would run the regular oil 5k to 10k and then replace. I run my synthetic gear oil 20k to 25k between changes. :)

smythcounty
05-21-08, 02:41 PM
Thanks...Yeah the mechanic said the back was harder to get to.