Drive train "clonking" sound ...

[Jan Larsson]

At stand still with engine running and switching between drive and reverse I have a "clonking" sound from the drive train. I need to go under there and see what it can be, sounds like metal moving and hitting something.

I have new U-joints (heavy duty version) that I installed about a year ago or so. Also a new poly torgue arm bushing installed about a year ago also.

Is there anything that can be loose? I will check all the bolts for the torgue arm and rear axle U-joint. Anything else I should look for??

The sounds is very loud and have not been this bad previously.

 

[1badTTA]

Sounds like the torque arm bushing, double check to make sure it is still good.

 

[Razor]

Tranny mount?

 

[gn4u2c]

gears going south in the rear. hope not
mine did the same thing new poly trans mount fixed it

 

[Jan Larsson]

Checked everything today, no loose bolts anywhere (rear u joint, LC's, swaybar, track bars etc). Also tranny mount and torgue arm bushing is ok. All bushings have less then 1000 miles on them.

Funny thing is that when I move the car this morning (cold been sitting for 2 days) trying a number of times standing on the brake and just moving between D and R and only noice I could hear is the noise from some bushings .... so no clunking sound. Could this the cluniking noise be when it was warm for some reason?

Also while under the car (trans in P) I grabbed the drive shaft and could turn it back and forth about 1/4 of an inch or less. So I guess this would be the back lash in the gears right? What would be normal or considered normal?

 

[72firebird]

My transmission makes a clunking sound too but my transmission mount is gone. Is there a good place to order a new transmission mount? Is the mount specific to the TTA or is it the same as all GTAs?

 

[Jan Larsson]

I got my transmission mount from Autozone, just ask for our car (think it's listed as a GTA SE or similar). Seems to work fine, if it's the same as for other GTA/TA's I'm not sure of but I would suspect so as I't looks similar.

 

[tta583]

Jan, same thing with my car. I just replaced the trailing arms with a boxed set using new bushings, the panhard bar with a boxed one and new bushings, all of the rear sway bar bushings, and the torque arm bushing. The trans mount looked great so I left it. All of the bushings are Energy Suspension. Still have my clunk.

There were some threads running around a year or so ago with various fixes that worked in various cars. I guess my next move is the trans mount then the rear end.

Brent

 

[Jan Larsson]

Got boxed LC's, all new bushings (poly) everywhere except for the trans mount but it's new as well as the support bushings in the trans crossmember (GM original ones). Picked up a BMR panhard bar I will install shortly. So I should have no noise from the suspension causing this .... also have a slight whining sound following the rpm of the rear .... Compared to my 84 Firebird with the 10 bolt and that one is very quite and no clunking at all....

 

[chicagoTTA]

Is this clunking sound coming from the rear when you hit a bump maybe?

There was a (somewhat) rare issue and a TSB (Technical Service Bulitin) was released.

The drivers rear had an issue with the parking brake.
I had this on my 88 GTA. You could sometimes reproduce the noise by hitting the drivers rear tire with your fist...

Just a thought.

 

[Jan Larsson]

I just have the clunking sound at standstill changing gear from drive to reverse, so I guess it's the backlash in the rear end gears ..... hope this is not too unusual ?

 

[Bird of Prey]

i have this "clonk" also at changing from P to R or D. I guess it's just the play in the drife-shaft. (kardan)

doesn't bother me at all.

 

[Quiky One]

I know this is an old thread, but my car has this too and I believe it just needs new ujoints. See if yours are going bad..

Jason

 

[Jan Larsson]

I know this is an old thread, but my car has this too and I believe it just needs new ujoints. See if yours are going bad..

Jason

Had brand new U-joints installed but still had the same sound ... not driven the car now for a year as the engine is still out so maybe it's all gone when I get it back together again sometime in the near future :biggrin:

 

[dvernst]

I had my rear end worked on last year, and the guy told me the noise is from the axle shafts having play where they go into the carrier.

 

[89ICBM]

Jan Larsson

At stand still with engine running and switching between drive and reverse I have a "clonking" sound from the drive train. I need to go under there and see what it can be, sounds like metal moving and hitting something.
[/QUOTE]


Howdy Jan!

What you heard is very normal. The rear end is a ring & pinion gear. I did see where you asked about this. Yes! Backlash is invoved but normally not a problem, the gears are designed to take that stress. When you shut the car down it's a crap shoot on what position the gears stop at. If they stop with the gears in forwared position and you start the car and shift to reverse you will here a clunck, a 'loud cunck', because the idle is generally up and the rear end gears slam together in a reverse direction. Try leting the car worm up a bit so that the car is in closed loop and the idle is down and see if it happins again. Worry about tranny mounts and other stuff if it continues when the car shifts. HTH

 

[SouthBaySurfer]

Thanks Frank. What you described is exactly what my car does. It never really bothered me, but it's nice to know that it's normal.