Mystery Clunk *Look in*
02-29-2012, 09:48 PM
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Mystery Clunk *Look in* I have a problem, need advice and knowledge if possible.
I have a 98 M6 T/A.
I had rubber motor mounts, poly trans mount, adj UMI torque arm, poly torque arm bushing and welded sub-frame connectors and no problems.
Then I added a T56 torque arm relocation crossmember from BMR. Because the the mounting point is adjustable I had to reset the pinion angle. I also added poly motor mounts and now I have a clunk that is driving me crazy. I check the clearance on the exhaust and the exhaust is not hitting anywhere. I also checked the clearance on the torque arm and the driveshaft and it is not hitting the body or each other at all.
The clunk/clunking happens every time and I decel in or out of gear or when I am braking lightly in or out of gear. It happens on small bumps and ripples in the road nothing big like speed bumps and pot holes. I have a feeling that it is my driveshaft. It has what seems to be alot play when I was under the car today. I do not get any vibration at any speed and no clunking at WOT or when shifting. It only happens at low speeds when deceling and its driving me insane. Can anyone lend an opinion?
Thanks,
Eric
I have a 98 M6 T/A.
I had rubber motor mounts, poly trans mount, adj UMI torque arm, poly torque arm bushing and welded sub-frame connectors and no problems.
Then I added a T56 torque arm relocation crossmember from BMR. Because the the mounting point is adjustable I had to reset the pinion angle. I also added poly motor mounts and now I have a clunk that is driving me crazy. I check the clearance on the exhaust and the exhaust is not hitting anywhere. I also checked the clearance on the torque arm and the driveshaft and it is not hitting the body or each other at all.
The clunk/clunking happens every time and I decel in or out of gear or when I am braking lightly in or out of gear. It happens on small bumps and ripples in the road nothing big like speed bumps and pot holes. I have a feeling that it is my driveshaft. It has what seems to be alot play when I was under the car today. I do not get any vibration at any speed and no clunking at WOT or when shifting. It only happens at low speeds when deceling and its driving me insane. Can anyone lend an opinion?
Thanks,
Eric
02-29-2012, 09:57 PM
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I have my rear end angle +1 degree, and driveline angle of the crank is -3 degrees. To me, from a 4x4 back ground I know that if I have -3 deg drivetrain angle from crank to tailshaft then I should have +3 deg rearend angle to minimize bind and vibration. The reason I left mine at +1 is so I have some room for movement at WOT. Does that make sense to you guys?
03-01-2012, 07:54 AM
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That makes sense to me (which isn't saying much). I have the tunnel mounted TA from UMI, and I too experience some nice clunking at slow speeds when starting to accel/decel. I have not experienced the clunking when going over slight bumps though. Have you rechecked all the bolts to make sure they're still good and tight? I had to tighten mine up a few days after my install, but that help some of the vibration I felt and not clunking...
03-01-2012, 06:20 PM
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I was just under the car and my torque arm has a couple little scratches on it near one of the brackets for the fuel lines. It may be hitting the head of the bolt that holds on the bracket. I don't think the minor amount of contact it is making is causing the clunk but I'm going to get a little more clearance one way or another and ill check back.
