2000 M6 Drivetrain Problem
Thread Starter
5th Gear
Joined: Nov 2017
Posts: 5
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From: Michigan
2000 M6 Drivetrain Problem
Hey everyone,
Having a unique issue on my 2000 M6 coupe with about 38k on the clock that I’ve been trying to research for some time but am not having much luck.
Basically, in first or second gear with about 10% throttle and turning the wheel slightly left or right, I get a loud grinding noise sometimes accompanied by a loud clunk. To me, it sounds like more of the middle of the vehicle or the rear that the noise is coming from, but it’s hard to pinpoint.
Here is what I’ve been able to research thus far:
Slave cylinder, possible something is wrong with this, but unlikely based upon my symptoms. No issues with the clutch pedal even after spirited driving. Fluid has been changed about 10 months ago and still appears clean and in good shape. Only reason I mention this is because I know the stock unit can go bad, but mine is not exhibiting any symptoms on this, but I could be wrong.
Torque tube, I personally think this is ok. I know that the bushings and bearings can go bad, but when they do they typically exhibit vibration symptoms through a certain RPM range, of which I have none of. I personally do not think it’s the torque tube.
Transmission, this is where it gets interesting. I’ve had the car up on the lift and have looked it over and everything appears ok. Fluid was changed with AC Delco recommended fluid awhile back and seems ok. I am slowly leaking fluid out of the weep hole on the trans, but I check the trans fluid level about once orr
month and I only had to put in a pump of a quart bottle before it was coming back out. I need to address the fluid leaking, but I fear that me be a bit involved and I’d like to figure out what’s happening before I start ripping into the car. The sound does appear to come from here, but after speaking with RPM for awhile, they stated first and second gear rarely has an issue, it’s always 3rd and 4th.
Now or for the rear end, I’m thinking this is the problem. Fluid was hanged with acdelco refommended fluid as well as limited slip additive. No issues with the car for 6 months after the rear end fluid was changed, so I don’t think it’s attributes to that, but it could be as none of this was going on when I bought the car. The CV shafts are fine, no play and no boots are torn.
Im thinking rear end because when I go in a parking lot and get some speed to do figure 8s, I’ll put the car in neutral to try and rule things out and I get no noise. Even if it’s in gear and I push the clutch in and turn, no noise. If I’m turning in second gear and push into the pedal more than 10% no noise because everything has enough torque on it and won’t make the noise.
Once im turning and just barely have my foot on the throttle, something sounds like it’s about to break with the combination of the popping and grinding sounds.
Has as anyone experienced anything like this or have any direction to point me in? I don’t want to just start ripping my car about without being able to diagnose what’s happening. It would be easier if it would just break!
Thanks for taking the time to read and respond. I appreciate all the support.
Having a unique issue on my 2000 M6 coupe with about 38k on the clock that I’ve been trying to research for some time but am not having much luck.
Basically, in first or second gear with about 10% throttle and turning the wheel slightly left or right, I get a loud grinding noise sometimes accompanied by a loud clunk. To me, it sounds like more of the middle of the vehicle or the rear that the noise is coming from, but it’s hard to pinpoint.
Here is what I’ve been able to research thus far:
Slave cylinder, possible something is wrong with this, but unlikely based upon my symptoms. No issues with the clutch pedal even after spirited driving. Fluid has been changed about 10 months ago and still appears clean and in good shape. Only reason I mention this is because I know the stock unit can go bad, but mine is not exhibiting any symptoms on this, but I could be wrong.
Torque tube, I personally think this is ok. I know that the bushings and bearings can go bad, but when they do they typically exhibit vibration symptoms through a certain RPM range, of which I have none of. I personally do not think it’s the torque tube.
Transmission, this is where it gets interesting. I’ve had the car up on the lift and have looked it over and everything appears ok. Fluid was changed with AC Delco recommended fluid awhile back and seems ok. I am slowly leaking fluid out of the weep hole on the trans, but I check the trans fluid level about once orr
month and I only had to put in a pump of a quart bottle before it was coming back out. I need to address the fluid leaking, but I fear that me be a bit involved and I’d like to figure out what’s happening before I start ripping into the car. The sound does appear to come from here, but after speaking with RPM for awhile, they stated first and second gear rarely has an issue, it’s always 3rd and 4th.
Now or for the rear end, I’m thinking this is the problem. Fluid was hanged with acdelco refommended fluid as well as limited slip additive. No issues with the car for 6 months after the rear end fluid was changed, so I don’t think it’s attributes to that, but it could be as none of this was going on when I bought the car. The CV shafts are fine, no play and no boots are torn.
Im thinking rear end because when I go in a parking lot and get some speed to do figure 8s, I’ll put the car in neutral to try and rule things out and I get no noise. Even if it’s in gear and I push the clutch in and turn, no noise. If I’m turning in second gear and push into the pedal more than 10% no noise because everything has enough torque on it and won’t make the noise.
Once im turning and just barely have my foot on the throttle, something sounds like it’s about to break with the combination of the popping and grinding sounds.
Has as anyone experienced anything like this or have any direction to point me in? I don’t want to just start ripping my car about without being able to diagnose what’s happening. It would be easier if it would just break!
Thanks for taking the time to read and respond. I appreciate all the support.
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If you had access to a 2-post lift the car could be run (wheels spinning) while someone else uses a mechanics stethoscope to rule out eigther side wheel bearing (by listening to the rear knuckle), the diff, trans, or torque tube. It could also be one of the cv joints in eigther axle. Even though you hear the noise when turning some residual chatter can be heard with a stethoscope on a lift.
Thread Starter
5th Gear
Joined: Nov 2017
Posts: 5
Likes: 0
From: Michigan
If you had access to a 2-post lift the car could be run (wheels spinning) while someone else uses a mechanics stethoscope to rule out eigther side wheel bearing (by listening to the rear knuckle), the diff, trans, or torque tube. It could also be one of the cv joints in eigther axle. Even though you hear the noise when turning some residual chatter can be heard with a stethoscope on a lift.
Put it the car on the lift and used the stethoscope to rule out the hub bearings and other rotational parts.
I actually found another forum post on here from about ten years ago where someone explained the exact symptoms that I did. They changed out their rear end fluid and all their issues were gone.
For grins, since I had already done the rear end fluid but was still almost positive it was isolated to the dif, I went out and bought the amsoil fluid and the additive.
Swapped the fluid out and double checked the trans and just got back from a 25 mile drive. I circled around the parking lot trying to replicate the issue and I could not. I feel like it was almost a little bit quieter, but that could just be in my mind.
The chattering i had was LOUD. However, everything seems to be fine now. I just hope no permanent damage was caused. Will keep my eyes on this one.
