That metallic clinking sound...

[MadRiver]

A month or so I put up a post about a metallic "clanking" sound I get from the tail end of Greenie sometimes when starting from a dead stop. It usually occurs if I'm not as gentle easing off the clutch. It happens once the car is rolling a bit, and then "clank" -- for those of you who lift weights, it is similar to the sound one weight makes when you add it to a bar that already has a weight on it, but not as loud. I've been all over the tail end, and aside from my loose shock (which made a very different sound), I haven't found anything loose. Last night, I down-shifted from fourth to third going up a hill, and heard the sound as well -- first time I've heard it in that situation.

It's clearly not the clutch and I very much doubt that it's the transmission, since it made it both before and after Greenie's transmission replacement, and my ears tell me it's coming from the back end somewhere. I also had the garage that did the tranny work look around, and they couldn't find any u-joint problems, but it is starting to worry me. I would very much appreciate the collective wisdom.

B.

 

[Andrew Mace]

I'm still thinking of spline wear on the driveshafts?

 

[MadRiver]

Thanks Andy -- Now for the magic questions -- How worried should I be, and what next?

 

[ROADSTR6]

It could possibly be a broken diff mount. Usually they make a chirping sound like a little birdy is following you around, but a clunk or clank is not out of the question. Inspect the mounts very carefully for cracks at the frame. My car had this problem and it's not an easy fix. Doable, but not easy. Good luck with your 6.

Dave

 

[John_Mc]

I would also think diff. mount, only because I had a similar problem. I looked it up on the VTR website and it seemed to point to that. When I did take it to the mechanic, he did so many things to it that it could have been driveshaft splines as well, as Andy mentioned. Here's the article about diff. mounts: TR6 Diff Mount Bracket Diagnosis and Repair

 

[jerrybny]

Could also be a Ujoint thats not installed correctly or worn out. I found one of mine that wasn't put together right. The caps on one of them wasn't all the way seated. It was making a little clanking sound every now and then. I tapped the capped down to where it should be and the noise is gone. I have already had my differential mounts re-enforced. It wasn't that bad of a job. Used an ATV jack stand to drop it and put it back in. The worst part of the job was dismantling the exhaust. /ubbthreads/images/graemlins/cheers.gif

 

[Harry_Ward]

When engaging the clutch hard I would hear a ting ting ting goes the spline on the splined drive shaft almost like the metal contraction noise you hear when heat from the exhaust disipates after the engine is shut off. I agree this could be your clank. The newer Z's are currently going through this type of spline problem. I have also heard this type of clanking clinking noise on my old painted wire wheels which were splined on high rpm clutch engagement. Might want to check your engine and transmission rubber mounts for wobble or cracks as well. If it's a metallic clunk or clang each time the clutch is engaged and disengaged I usually suspect the clearance (wear) between gears either rear or tranny. If it's a steady continuous thumping noise it's usually the u-joint bearings freezing up or broken causing the drive shaft to be spinning off centered (best way I can describe it). When it gets worse the u-joint noise turns into a steady thumping whumping noise and gets louder and faster with higher engine rpm. If it gets worse than that you hear a big bang and can't go anywhere. I would jack the car up and see how much free play you may have in the shaft and rear differential. If there is any movement I would remove the shaft and inspect the splines. My last thought is could it simply be due to torque causing the front end up and the rear taking a squat on some part of the axle or frame?