Drivetrain slack

[1987MA]

I am trying to figure out what is causing a "clunking" sound from the rear of the car when I shift / accelerate / decelerate. I think it has to be something in the drivetrain or related systems, as it does not "clunk" when braking, turning or going over bumps. I thought that it was the rear subframe bushings, but I just installed a set of aluminum spacers (http://www.beechperformance.com/html/toyota_products.html), and that made the problem worse. Now, the "clunk" is still there, but is sharper and there is a lot more road noise.

The spacers did not come with instructions, so I hope I installed them correctly. I put them between the subframe and the body, replacing the rubber spacers that were there previously. Is that the correct way to install them?

If that isn't the problem, what other parts could be causing my problem? It isn't the driveshaft bushing, since I replaced the stock driveshaft with a one piece aluminum driveshaft, and I don't think there's any play there. Maybe the differential mounts?

 

[Nick M]

Aluminum in place of rubber bushings will transmit more sound/vibration. You can look at the u-joints, but they usually vibrate like a bad tire and the frequencey increases with road speed. Get the car in the air and look for the freeplay. Along with trans mounts that look like they are shifted.

 

[1987MA]

I've had it up in the air several times, and haven't found any play in the drivetrain. The clunking seems to be coming from the rear, so I don't think it's the transmission mounts. I have it in the garage now, so I'll check again...

 

[Moy]

the diff solid mounts to the rear subframe. check for cracks. also check the pinion gear free play, it's possible that you have excessive backlash in your differential's ring and pinion and can be causing said clunking.

 

[Flateric]

I think Moy is correct, mine was doing this after years and years of elevated power levels and drag racing. Diff was simply worn out and tired. Luckily I had a good spare on hand and switched it in.

 

[Backlash2032]

the diff solid mounts to the rear subframe. check for cracks. also check the pinion gear free play, it's possible that you have excessive backlash in your differential's ring and pinion and can be causing said clunking.

Mention me? :biglaugh:

 

[Dylan JZ]

as others have said, check the diff lash.. really common unfortunately.