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Hey guys, first post here. Recently picked up an 07 70k M6 and only put about 300 miles on it so far.
Went to put it in reverse last night and felt it basically grab like the e-brake was still engaged or as if I was running over something. Chalked it up to thinking it was just the brakes since it had just got done raining (maybe rusty rotor) but then heard a noise as I was driving that got louder the faster I went. Parked it and waited until the next day and drove it to my shop and noticed the noise has gotten louder.
Jacked it up and spun the wheels and noticed it sounded like it was coming from the diff casing. Just rotating the wheels it sounds like something metal dropping inside it. Assuming it’s maybe a broken gear tooth?? Ill post a link to a video so you can hear as well.
My question is if I have to pull the diff what upgrade do you guys recommend while I’m in there? Gear ratios and all that are something I’m a little unfamiliar with. Thanks
Welcome to the forum. The video link didn't work
It is possible that the rear axle nuts have loosened, which will cause a scrapping noise coming from the rear end. You can check to see if they are loose. They are supposed to be at approx 140 ft-lb. If they are loose, they have to be replaced with new ones as per a GM Technical Service Bulletin (TSB).
There is also a TSB on the rear diff fluid.
I'd be checking these before removing/replacing the differential. I have a 2006 with 124K miles, and I did do both of these TSB's myself. I used a diff fluid that was not GM fluid, and it would not quiet down. I drained the Redline fluid, replaced with GM OEM fluid, did a bunch of figure 8's to fill the clutch plates in the differential, and the differential is as quiet as a church mouse. I changed the axle nuts at the same time, just as a preventative action.
Welcome to the forum. The video link didn't work
It is possible that the rear axle nuts have loosened, which will cause a scrapping noise coming from the rear end. You can check to see if they are loose. They are supposed to be at approx 140 ft-lb. If they are loose, they have to be replaced with new ones as per a GM Technical Service Bulletin (TSB).
There is also a TSB on the rear diff fluid.
I'd be checking these before removing/replacing the differential. I have a 2006 with 124K miles, and I did do both of these TSB's myself. I used a diff fluid that was not GM fluid, and it would not quiet down. I drained the Redline fluid, replaced with GM OEM fluid, did a bunch of figure 8's to fill the clutch plates in the differential, and the differential is as quiet as a church mouse. I changed the axle nuts at the same time, just as a preventative action.
Good Luck
.
Tried the axle nuts and they were fine. Drained the diff fluid and it’s definitely fried. Pieces of the casing I’m assuming came out whith only about 1qt of fluid. Spinning the tire with my hand I can still hear pieces in it and in some spots it’s hangs up in reverse.
Any recommendations on an upgraded diff or should I source one off eBay? Is the only difference in the Z06 and base the diff cooler?
Tried the axle nuts and they were fine. Drained the diff fluid and it’s definitely fried. Pieces of the casing I’m assuming came out whith only about 1qt of fluid. Spinning the tire with my hand I can still hear pieces in it and in some spots it’s hangs up in reverse.
Any recommendations on an upgraded diff or should I source one off eBay? Is the only difference in the Z06 and base the diff cooler?
The only thing Ive heard that goes bad in the diffs is the belleville washers. I have never seen that kind of junk come out of a pumpkin before. I wish you the best. Someone who has had issues will chime in soon. As for 1qt coming out, they usually hold like 1-3/4qts, iirc....
YIKES!!!! That is a mess for sure. I have 124K miles on my OEM 2006 Diff, and I've had no issues, but I don't race the car. This one had some major torture put on it to do that damage, or it was run low of fluid. I believe it takes just over 2 quarts in my Z51 optioned car.
Rear Diff Issue
