Noise in Rear Diff.

First major issue. knew I spoke to soon when asked how the car was running.
Little up hill shutter from stop last Oct.08 stored nov.1 to may1 . Shop drain refill fluid april 9,09 then back in storage till nov.1 backed out drive little noise, drove to parking lot to do figure 8's Noise so loud clattering, clanking afraid to drive. Back to shop, no metal shavings, but they are now replacing everything, clutch packs & all. My ? is anyone know if the 2 fluid #88862624
now contain the additive also ? That is what I was told by service. Service is unable to determin what actually happened, so they are going to replace all.
Two xlr techs seem to be very knowlegeable but on my invoice it only shows 2 fluids no additive, just seemed to happen all to sudden.

I just checked my shop manual ('04) and it lists the synthetic axel lubricant as GM P/N 1237826 and limited slip differential lubricant additive as GM P/N 1052358. The manual says there should be 4 oz of additive for every 1.69 qts of lubricant.

Now for the newer stuff:

What you're referring to is: DEXRON® LS gear oil, P/N 88862624 (Canadian P/N 88862625). It doesn't need additional additive.

Adding the limited slip differential lubricant to this newer lubricant can degrade friction performance and seal life.

Keep us posted when they figure out what's causing the differential chatter, okay?

CC :cheers

dws and CC:

FWIW: I just had my fluid changed in at the dealer and it seems that Cadillac is now a fan of Mobil 1 rear end differential lubricants as a upgrade for their product.

I think that it does really work better than the GM stuff but we'll see.....

dws and CC:

FWIW: I just had my fluid changed in at the dealer and it seems that Cadillac is now a fan of Mobil 1 rear end differential lubricants as a upgrade for their product.

I think that it does really work better than the GM stuff but we'll see.....

You are right about the MOBIL1, they swiched a while ago, anything would be better than the gm stuff. First time I heard you didn,t have to add the additive, service said they added in with lube. If thats true then Im not going to have to wait to switch over to Castrol, or ROYAL PURPLE they are in proccess of developimg the additive. I don't care much for mobil1 oil but I do use the fuel, for ever, but thats about to change to Shell.
ccclarke & xlr 1FL thanks for the quick response, keep you posted on the fix.