Mildphil

So basically when I shift casually (not fast or hard, just normal) the transmission or something in the center of mass of the car seems to clunk/bang in a forward/back jerking motion, (not extremely hard, but like you hit a bump, that hard) also, if I let off the clutch a little fast and sometimes normal, it does this. This also happens if I let off the gas quickly. Does anyone know the possible cause of this problem? Apparently it is as common as the squeak our cars make when going over speed bumps. Any info would be greatly appreciated, It can sometimes make driving stick frustrating because u have to shift fast& baby the clutch and gas to have a smooth ride and keep from having the clunks.

RevGTO

iTrader: (12)

Transmission mount. My current M6 car had the same problem when I bought it.

Mildphil

Does it feel much better shifting now?

fleetmgr

That's like asking someone if it feels better after their finger quits hurting because they just bashed it with a hammer....

Mildphil

Except is isn't at all.

maroonls1z

Check the transmission mount first, if not it then torque arm mount, if both of those check out then you may have a problem on the inside of the transmission... Which is what I had, think I broke a bearing somewhere allowing movement in the main shaft but havnt broken it down to determine. Swapped the transmission and no more clunk on shifting and stopping

Mildphil

I was thinking it could be the tranny mount or torque arm mount. It never clunks after 2300 rpm, but around 2k it will clunk back and forth, and it always clunks when ship shift activates, unless if I let the clutch out real slow.

maroonls1z

Well it's easy enough to check the mount and even cheaper to replace. Start there and if neither is ripped start thinking other things

Mildphil

check my trans mount. Think is shot to hell, damn. Reached my hand under my car to grab it and pull out chunks of dried black rubber

RevGTO

iTrader: (12)

Yes, replacing the mount completely solved the problem, and the thing is, it appeared completely fine to the naked eye when I pulled it. With yours visibly completely falling apart, the difference will be night and day.

Mildphil

Yeah thanks a lot, because mine looks fine to me, so I was worried it might have been something else that might be damaged. My shifter also vibrates, and can be notchy at times, so if you had these symptoms and it is fixed then this really narrows it down. Did you use an OEM mount or something else? (here is a video of my mount had trouble positioning it but you can still see it. )

CaliboyTA

iTrader: (2)

Also check ur torque arm mount. When my torque arm mount crapped it started to make clunky nose everytime I shift

Mildphil

I checked the bushing and it looked ok but there were some gaps where it wasn't touching the arm and when I touched/rubbed it rubber started chunking off, so I think I have found the problem. I can post a video if anyone wants to see it. Anyone know a good place to find the bushing?

Mildphil

is this the right part? there are other parts that look very similar but they don't specify year.

RevGTO

iTrader: (12)

It's a common and readily available part. I got mine from some regular auto parts store. I don't remember which one or what the brand was.

RevGTO

iTrader: (12)

That's a polyurethane replacement. Poly is known to increase vibrations and harshness. I would stick to stock rubber in both places.

Mildphil

Alright. I will call up somewhere tomorrow and get a rubber replacement. Heard it is a bitch to install though because of the top bolt or something.

CaliboyTA

iTrader: (2)

i bought a poly one from amazon. i dont remember any extra vibrations. I also have a energy suspension poly trans mount that im selling if u want one. $20 shipped

Darth_V8r

iTrader: (4)

I don't know if you thought of this, but I found it by accident. I pulled the air injection hose at the fitting near the driver shock tower and plugged it as a temporary bypass to theair system, and the car quit clunking. Hooked it back up to pass emissions, clunking returned, which is when I put two and two together. The check valve was leaking, causing cold air to enter the exhaust and make a small backfire, but it sounded just like the y pipe was hitting the transmission case when shifting. What clued me off was your "even happens when I suddenly let off the gas".

Quick and easy to check if you haven't already plated off your air injection ports

discombobulator

torque arm rubber bushing is the clunking when shifting i aint sure if its supposed to but id say sort of is cause as you take off the rear end tends to rotate forward so th armis pushed down, then when you let of gas the bar goes up thats the play and banging you hear