I have seen this twice now...rear diff?

YellowCrewCabber · Post by **YellowCrewCabber** » Thu Jan 15, 2009 9:47 am

We are"NOT" suppose to ad friction modifier to the rear diff's? Oh dear, I need to know why.

MY 100th post. I'm an elite now!!

Yes I can be a bit of a goof ball.

raven2510 · Post by **raven2510** » Thu Jan 15, 2009 10:10 am

b/c of the G80 in the rear. it uses clutches to work and they mess with the normal operation

YellowCrewCabber · Post by **YellowCrewCabber** » Thu Jan 15, 2009 10:43 am

raven2510 wrote:b/c of the G80 in the rear. it uses clutches to work and they mess with the normal operation

Grrrrr. if mine is a G80 which it probably is, (it does have clutches in it) I will have to say the mechanics around here are FRIGGING idiots. Which also means it will be the 5th time I will have to pull the cover off because of some FRIGGING idiot mechanic.

YellowCrewCabber · Post by **YellowCrewCabber** » Thu Jan 15, 2009 10:50 am

Wait!! I have to ask this...Did GM ever recommend adding friction modifiers to the G80 differential?

Post by **HenryJ** » Thu Jan 15, 2009 11:00 am

YellowCrewCabber wrote:Wait!! I have to ask this...Did GM ever recommend adding friction modifiers to the G80 differential?

No

YellowCrewCabber · Post by **YellowCrewCabber** » Thu Jan 15, 2009 11:08 am

OH DEAR, OH DEAR, OH DEAR!! G80 is listed in the glove box. This would explain why it's not working like it should.

I'd really like to put that repair shop out of business. There's more to this story. OMG those idiots.

Post by **HenryJ** » Thu Jan 15, 2009 12:09 pm

It is best to be an informed consumer. Better yet is , if you want the job done right do it yourself.
The support system for doing this is here. The combined experience of the owners here far exceeds any training a service tech might receive on this vehicle.
We are all here to walk you through it if you feel the need.

YellowCrewCabber · Post by **YellowCrewCabber** » Thu Jan 15, 2009 4:26 pm

Thanks HenryJ. I totally agree with the knowledge that has accrued here. At the time I had an extended warranty which turned out to be crap. (after market and please spare me the grief)

and have never been into a rear diff. other than removing axles to change seals. Anyway I thought it would be best to let the "experts" do it. Turns out to be contaminated with water, clutches are basically not even there. The shop supervisor then tells me about having to ad the friction modifier and that the new clutches would have to be "pre-loaded". From that moment a large knot of doubt fell into my stomach. BTW this is an SAE certified shop. There is more and it gets better. Would you like to hear it??

Post by **HenryJ** » Thu Jan 15, 2009 4:35 pm

ASE certification around here is kind of an inside joke. It means I paid my $10 and got the patch

I too am ASE certifiable

I hope you relocated the vent tube to prevent more water.

That was likely the demise of the clutches more so than a friction modifier.
Friction modifiers are used on limited slip differentials. The Eaton Gov-loc we have is a different beast. I am not sure you could blame damage to the differential on the modifier , if water was present.

Sorry for your woes. Hope things work out.

YellowCrewCabber · Post by **YellowCrewCabber** » Thu Jan 15, 2009 6:45 pm

No not blaming the modifier. Definately the water. Haven't relocated the hose, yet.

Post by **HenryJ** » Thu Jan 15, 2009 6:46 pm

Do that now. The information has been around for quite a while. The link for TSB information may still be here as well.