Pontiac Solstice Forum - View Single Post - Info From GM Engineer Q&A [from International Solstice Meet]

My differential makes a Clunking noise/whining noise/both. Is there any way to fix this? Is GM aware of the issue?
In short, yes, GM is aware of the issue. There is no 'fix' for shifting clunk or whine.

Addressing Misinformation:
The clunk and whine is not an indication of any near-term failure, it is unaffected by different fluids (and as a matter of fact only the recommended fluid and additive should be used), and cannot be solved by changing differential mount bushings to harder or softer bushings. The clunk and whine are unrelated issues to the pinion seal leaks.

Some facts:
Limited slip differentials tend to be more noticeable than open differentials. Whine can vary in intensity, and clunk can be more noticable if the differential is heated up. The source of the noise is the differential, not the transmission. Whine has some influence on break in, so avoid wide open throttle starts and vary the speeds in your car for the first 500-1000 miles. The effects of break-in are not huge, but severely treating your car in the first 1000 miles is not recommended and is certainly not good for the differential. The clunk is not as much of an issue in Solstices with the automatic transmission. The clunk is also dependent on driving style, and upshifting at a higher RPM can reduce clunk in your car.

All RWD differentials clunk to some extent, and most will exhibit some whine, even on competitive vehicles. The issue exists on the Solstice because we had to use common parts with the CTS/STS including the type of mounting. In the Solstice, the differential is mounted directly to the structure and noises coming from the differential have a direct noisepath.

We are looking at ways to sucessfully address this issue from an engineering standpoint for future cars, but there is no fix for current cars already produced. I am sorry to bring you that news, but I would rather be honest then mislead you.

__________________
I don't suffer from insanity, I enjoy every minute of it!

#139640 '07 NA Sly Fully Loaded 12/1/07
#106614 12/15/05 NA Sly Traded @ 35k Miles

Be too blessed to be stressed! ~ Joel Osteen
If you get a second chance, grab it with both hands. If it changes your life, let it.

NASSOA(TM)
Founding Member- Council Chair

	MomsSol Moderator Join Date: Nov 2005	My differential makes a Clunking noise/whining noise/both. Is there any way to fix this? Is GM aware of the issue? In short, yes, GM is aware of the issue. There is no 'fix' for shifting clunk or whine. Addressing Misinformation: The clunk and whine is not an indication of any near-term failure, it is unaffected by different fluids (and as a matter of fact only the recommended fluid and additive should be used), and cannot be solved by changing differential mount bushings to harder or softer bushings. The clunk and whine are unrelated issues to the pinion seal leaks. Some facts: Limited slip differentials tend to be more noticeable than open differentials. Whine can vary in intensity, and clunk can be more noticable if the differential is heated up. The source of the noise is the differential, not the transmission. Whine has some influence on break in, so avoid wide open throttle starts and vary the speeds in your car for the first 500-1000 miles. The effects of break-in are not huge, but severely treating your car in the first 1000 miles is not recommended and is certainly not good for the differential. The clunk is not as much of an issue in Solstices with the automatic transmission. The clunk is also dependent on driving style, and upshifting at a higher RPM can reduce clunk in your car. All RWD differentials clunk to some extent, and most will exhibit some whine, even on competitive vehicles. The issue exists on the Solstice because we had to use common parts with the CTS/STS including the type of mounting. In the Solstice, the differential is mounted directly to the structure and noises coming from the differential have a direct noisepath. We are looking at ways to sucessfully address this issue from an engineering standpoint for future cars, but there is no fix for current cars already produced. I am sorry to bring you that news, but I would rather be honest then mislead you. __________________ I don't suffer from insanity, I enjoy every minute of it! #139640 '07 NA Sly Fully Loaded 12/1/07 #106614 12/15/05 NA Sly Traded @ 35k Miles Be too blessed to be stressed! ~ Joel Osteen If you get a second chance, grab it with both hands. If it changes your life, let it. NASSOA(TM) Founding Member- Council Chair