I have a scraping, rubbing noise from the right rear when turning sharp to the left. Turning right causes lesser noise from left rear. Both of these are when turning the car slowly.. I have crawled around underneath the rear and can see nothing which is rubbing. I thought maybe it was the clamps on the outside of the half shaft seals but don't see anything amiss. 2007 Indy Pace Car with Z51 package.
Scraping rubbing noise from rear when turning slow
- Thread starter 1 BAD 9T9
- Start date
Wheel bearings do that when they are on the way out. Might that be a place to look?
Thanks OL Yeller I'll check them out, but my car only has 25,000 kilometres so I find wheel bearings unlikely, plus there is no noise going straight..
I talked to some buddies in my local club and they all feel it is the limited slip diff, Add some "Whale oil" to the diff and should go away they say. However this does not explain why the noise comes from the opposite side to the steering direction and not from the centre.
Any more ideas?
Bad wheel bearings won't make much of a noise when going in a straight line, mostly when the strain comes on the affected wheel. 25,000 km isn't much milage but stranger things have happened.
I will try and stethoscope the bearing housing with the axle turning and that should tell me if I have a bad bearing. I will also check differential fluid level and if wheel bearings check OK will try and find some whale oil
Did some more research and found out Whale Oil is what they used back in the C3 days and now it is non existant. However I also found the thread which makes the most sense. I know it is an old post, however after reading I think this is my problem. There is also a post on the US Corvette Forum that basically says same thing referencing Summit Racing and a C7 Z06 regarding the correct part number.
Some advice for Corvette owners re diff oil
- Thread starterG-MAN
- Start dateOct 23, 2016
[IMG alt="G-MAN"]https://secure.gravatar.com/avatar/6f2f3d2857093ae056c1e0a4fa86c6bc?s=96[/IMG]
G-MAN
JoinedNov 15, 2002Messages8,937LocationSCRight after I got my (new to me) 2005 Corvette, I had the dealer change the transmission fluid and the rear differential fluid. Within a day of having this service done, I started getting weird scrubbing and crunching noises in low speed, tight turns (like in the cul de sac at the end of my street). I checked the dealer invoice to see what diff oil they had used and it was GM part #88900401 full synthetic 75w90. I looked this up online and it is not a limited slip diff oil and there was nothing on the invoice to indicate that they had added any limited slip additive. I called the dealer about this and was told that 88900401 is the diff oil listed in their computer as the correct oil for a 2005 Corvette and no limited slip additive is needed. Okay, but what about this noise? They wanted me to bring the car in and leave it with them for a full day so they could diagnose the noise. I had an appointment for them to do that this past Friday and they were going to give me a loaner car gratis for the whole day. However, earlier last week I did a lot of research about this online and I discovered 88900401 is NOT the correct fluid for C6 differentials. GM issued a TSB (#07-04-20-002A) in 2008 detailing this noise from the differential and specifying a new gear oil that was specifically developed to eliminate chatter from the clutch pack of the limited slip diff on the C6. The new oil is Dexron LS 75w90, GM part #88862624 and it's been the factory fill in all Vettes (C6 and C7) since the 2008 model year. So, long story short, I decided to forgo the appointment on Friday. I went to the dealer and bought three quarts of the Dexron LS ($26 a quart!) and had my local shop change it out. Noise gone. Problem solved. So, if you have a C6 Vette and ever have any strange noises from your rear end, or just decide to change the diff oil as a preventative measure, be sure to use the Dexron LS, part #88862624.
Have you had your diff fluid changed? I did mine this year and replaced it with this. The additive is already included. No guess work on the correct amount to add.
I have no idea. Bought car about three years ago and have only driven it a little bit due to Covid. I have no record of what previous owner did and haven't even checked fluid levels. Probably best to drain and refill with the right stuff, Thanks for your input.
Peter, I bought Mobil 1 Gear Oil with the Additive already in it. I think it took 1.5 litres for my C5 Diff. The C5 uses crush washers for both of the the plugs, I bought them from GM, stupid expensive but you probably know alternatives. I had a leaking seal on mine when it was still under warranty but the mechanic did not replace the washers, it continued to leak. Did it all again. I used a boat motor lower unit pump, heated the oil in hot water made the pumping a little easier.
There is a process of driving in a figure 8 after changing the fluid, supposed to ensure the clutch packs get equally lubricated. I think you have to avoid full throttle starts for some time as well. May not be your problem but it might just be an inexpensive way to find out.
Good luck getting it sorted.
There is a process of driving in a figure 8 after changing the fluid, supposed to ensure the clutch packs get equally lubricated. I think you have to avoid full throttle starts for some time as well. May not be your problem but it might just be an inexpensive way to find out.
Good luck getting it sorted.
Thanks guys. Looks like a three beer project to get this done before snow gets here. Now I need to find a marina to lend me a boat motor lower unit pump. LOL
I can buy Royal Purple at CTC but cannot find Mobil 1 gear oil anywhere here in Windsor, Ontario. Will the Royal Purple cure my noise with the diff clutches or will I end up with the GM problem of two similar viscosity oils (88900401 bad & 88862624 good) and have it equal the bad one and not cure the problem. Maybe my Chevy dealer sells the correct number GM stuff. What do you guys think?
I also will need two new crush washers. Yes/no?
I can buy Royal Purple at CTC but cannot find Mobil 1 gear oil anywhere here in Windsor, Ontario. Will the Royal Purple cure my noise with the diff clutches or will I end up with the GM problem of two similar viscosity oils (88900401 bad & 88862624 good) and have it equal the bad one and not cure the problem. Maybe my Chevy dealer sells the correct number GM stuff. What do you guys think?
I also will need two new crush washers. Yes/no?
I didn't replace the crush washers. Just torqued to the correct ft./lbs and haven't had a problem. That said, if you can get them, you should. I just put 2 1/2 bottles of the Royal Purple in, using a hand pump laying on my back under the car. Tight quarters but it can be done. Filled until it started to flow back out, buttoned it up, took it for a little drive, did the Nascar thing swerving back and forth for a while did a few figure 8s on a parking lot and came home. Not a squeek, shudder, grind...nothing...all good (for me) YMMV
Thanks OL Yeller for the update.
Have found 2 litres GM88862625 at local Chev dealer for $24.00 each so I think that is the way I will go. Like you I have a little hand pump that screws onto the one litre bottle and I will get lots of thumb exercise transferring the fluid. The GM service bulletins say to do the figure 8 exercise immediately after changing the oil as well as defining the part number for Canada. US number is 88862624, why it should be different for us Canucks I have no idea.
Regarding the washers, Chev dealer had no stock, plus they are $12.00 each. Service people say so long as you torque to the correct reading should have no problem with leaks. I'll try just like you did.
By the way, what is the metric term for mileage as in YMMV?
All done! First drove car hard for about 20 kilometres to heat up lube in differential. Took longer to get car level on jack stands than to change the lube. Actually loaded chassis to right by putting stand under left front jack point and then lifting rear end so it teetered a bit to right with front to rear of car level. The drain plug is on passenger side so this helps with draining. Only took about 20 minutes to drop the plugs, drain the lube and then pump in the GM gear lube with my little pump that screwed into the 946 ml container. Did the figure eight trick and noise was gone immediately, just like OL Yeller..
Today I added fuel stabilizer to gas tank and put battery on tender and then put her car cover blanket on for the big sleep.
Remember you C5 and C6 guys, only a quarter tank of fuel to avoid problems with gas guage caused by fouled fuel tank sender. Not sure about C7's or C8's.
Today I added fuel stabilizer to gas tank and put battery on tender and then put her car cover blanket on for the big sleep.
Remember you C5 and C6 guys, only a quarter tank of fuel to avoid problems with gas guage caused by fouled fuel tank sender. Not sure about C7's or C8's.
