Axle Clunk/Chatter Noise on Turns

[Small Dealer]

Here is some updated information out this week for owners to think about with the good weather returning for Spring maintenance.

Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns (Drain/Refill Rear Differential Fluid) Models: 2003-2010 Cadillac CTS (Including V-Series and Export) 2004-2009 Cadillac SRX (Including Export) 2005-2010 Cadillac STS (Including V-Series and Export) 2006-2008 Pontiac Solstice 2007-2008 Saturn SKY Condition Some customers may comment on a clunk and/or chatter type noise from the rear of the vehicle while making turns. This condition may be worse on vehicles built prior to the 2008 model year. Carbon-faced clutch plates were introduced into production in the 2008 model year and have decreased the likelihood of the clutch plate chatter. Cause This condition may be caused by slip/stick of the posi-traction clutch plates due to insufficient limited-slip axle additive. As plates slip and stick, a jumping or jerking feel occurs accompanied by a clunk noise. Correction Important: DO NOT remove the differential cover. It is not necessary to flush the old fluid from the differential. Drain and refill the rear differential with new fluid, GM P/N 88862624. Refer to the Axle Lubricant Change procedure in SI. This new fluid includes a friction modifier already added with a different formulation that last longer and does not break down overtime. Lubrication Specifications Quantity Without Differential Oil Cooler 1.10 L / 1.16 qt With Differential Oil Cooler 1.41 L / 1.50 qt Parts Information 88862624 (US -1 qt) 88862625 (Canada - 1 L) DEXRON® LS Gear Oil

[WintR]

Thanks, SD. Good to know. I'm keeping a copy in my Solstice data, just in case.

[lightning rod]

thanks Small Dealer

I have been changing the diff fluid every 20,000 km to keep the

groaning to a minimum

changed to the new fluid and the groan totally disappeared

[shreve1]

I just had my diff replaced last week. They rebuilt it last year due to clutch pack ware. Then the past month it was whinning like mad. Took it in and they removed my diff. Once they broke it down they found the pinion and ring was shot. So they decided to replace it with a complete new diff. Now it smooth and quiet.

[Small Dealer]

Originally Posted by lightning rod I have been changing the diff fluid every 20,000 km to keep the groaning to a minimum, changed to the new fluid and the groan totally disappeared.

Thanks for the input.

[GaryH]

Originally Posted by lightning rod thanks Small Dealer I have been changing the diff fluid every 20,000 km to keep the groaning to a minimum changed to the new fluid and the groan totally disappeared

My clutch packs were replaced under warranty and I haven't had any problems since. Is replacing the fluid every 20,000 km (12,400 miles) necessary?

[lightning rod]

Originally Posted by GaryH My clutch packs were replaced under warranty and I haven't had any problems since. Is replacing the fluid every 20,000 km (12,400 miles) necessary?

Gary ;

probably not. I took the car to the dealer and they said some groaning was normal. The groaning wasn't always there, just on the really hot days.
The dealer just wanted to change the fluid.

Changing the fluid (original part number) regularly seemed to help.
There was very little clutch material on the magnet of the drain plug.
My brother-in law (mechanic - shop teacher now) suggested to change to a
different fluid since that helps sometimes.
Well I guess GM figured out a better fluid.

The new fluid is like magic. Not even a hint of groan.
I never got this when changing the old part number fluid.

I'll let you guys know in 10,000 km if the new fluid is holding up.

Ross

[jimbo]

Thanks. You are an indispensable resource.

[69telecaster]

I've been doing a bunch of reading on this site about the rear end and the lubricant(s). Mine doesn't chatter on low-speed turns, but it whines at speeds over 55. PO had the diff. changed, under warranty, some time ago.
I'm thinking I want to change the fluid, but now there's questions about the fluid. I asked the dealer parts desk about #88862624, and was told they'd have to special order it...very rare, possibly old number. He showed me bottles of the lube they use: a GM and a Mobil1 product. Both said "synthetic" and "LS". I looked at the display at a local parts store, and saw Royal Purple and Valvoline bottles with similar designations.
I assume the #89021677, #12378261, and additive #01052358, mentioned in another thread (Feb. & Jun. '08), are the "old" fluids.
I guess I want to know what is currently recommended by GM, and are Mobil1, Royal Purple, and Valvoline acceptable substitutes. Also, what is the recommended change interval?
Thanx.
cm

[NormSky]

69, I don't GM recommends any other differential fluid. There fluids which meet or exceed their requirements. Personally run Royal Purple(with LSD modifier all ready in it) 85-140 in my 2005 CTS-V and only have a. Slight whimpering. I run RP 75w90 in the Sky.


Norm

[jeffgtx]

Is the above procedure as documented by Gm a warranty service or do you have to pay?

I started getting the clunk. Thought the fire extinguisher was loose in the trunk. Took it out. Thought the exhaust was loose.

Glad to stumble on this.

[69telecaster]

Originally Posted by NormSky 69, I don't GM recommends any other differential fluid. There fluids which meet or exceed their requirements. Personally run Royal Purple(with LSD modifier all ready in it) 85-140 in my 2005 CTS-V and only have a. Slight whimpering. I run RP 75w90 in the Sky. Norm

Thanks, Norm.
I know others who swear by Royal Purple products, so I'll give it a try.
How often do you change yours?

[NormSky]

Use whatever and just follow manufacturer maintence schedule. Unless you use your car for track duty. The drain plug is magnetic and will fill up with metal particles as it's a heavier car using the same diff. I'd personally change it, it can be a messy job, inspect the drain plug for metal particle/sludge. If you have 1/4" or more of build up on the drain plug, change it again in 10-15,000 miles. While your under there might as well change the transmission fluid as well if it's a manual. Might even see a bump in mpg.


Norm

[69telecaster]

My owners manual maintenance schedule doesn't say anything about the rear end or manual trans. fluids, out to 150,000 mi. Of course, it says that if anything goes wrong to take it to the dealer...heh, heh.