Drive line clunking - 3000GT/Stealth International Message Center

artiec1 · 10-03-2009, 03:16 PM

If I'm cruising and tale my foot off the gas and reapply gas it clunks.

When stopped and engage the clutch, it clunks. It sounds like the whole drive train but I think it's one piece.

Transfer case, rear diff, trans, u-joints.

Any ideas on how to narrow it down.

Thanks

sheldo81 · 10-03-2009, 03:19 PM

check carrier bearings. how much play are they allowing?

Lenn · 10-03-2009, 03:20 PM

I have the same problem from time to time. Mainly when putting the car into gear. I do know that my driveshaft bearings are poop. I would start by checking those. Apparently, if you can grab ahold of your driveshaft and move it around inside those bearings, there tits up. Mine moves freely inside those and also makes a squishing sound so I assume that they are bad. Haha.

artiec1 · 10-03-2009, 03:26 PM

Forgot to say - new carrier bearing less than 10,000 miles ago.

TT Eric · 10-03-2009, 03:27 PM

Raise your car and turn the driveshaft to see where the slack is! It can be the driveshaft itself, the rear dif, the tranny... me I had some slack in the tranny after the rebuilt I got rid of it!

Eric

artiec1 · 10-03-2009, 03:28 PM

New carrier bearings not long ago. It feels like the whole drive train has play in it somewhere. Driving me nuts. I'm thinking maybe the rear diff .

artiec1 · 10-03-2009, 03:30 PM

I will do that. I really hope it's not the trans. Trans shifts great in all gears. When I changed fluid in trans and transfer case it was in good condition with no metal or burning I could detect.

TT Eric · 10-03-2009, 04:27 PM

What I did when the backslash was bothering me :

1) I had a small slack in the driveshaft so I replaced it by a CF one : did not get rid of the 'thumb' sound, but it was smoother (34 lbs less)
2) Put an almost new rear diff, cause I had some slack in it = bad thing, the bigger slack was in the tranny, so after 6 months the rear diff was slack again.
3) Sent my tranny to JacksTransmissions and rebuilted it with no slack, rebuilded my TCase too and I rebuilded my rear diff locally. + While we were there, my clutch's disk had some spring loose, so we replaced the disk, that must helped too.

I had very little slack on the axle too, but very minimal.

Now the car is thight.

It may be just the rear diff, but look if you have some in the tranny too, because you could end up like me!

Eric

stealthfighter94 · 10-03-2009, 04:40 PM

how bout the differential bushings?

Stegmann · 10-03-2009, 05:48 PM

Before you worry about driveshaft backlash, diff bushings, blah blah, you should start with checking the first potential source of looseness in the drive train - motor mounts. It's an easy test. Just pop your hood and start rolling up the road in 1st, then after 3,000 rpm watch the motor and let off quickly and then jab the throttle. If your motor mounts are shot, trust me you'll know it. The whole motor will buck forward. The mounts on my vr4 are shot, and the whole drivetrain clunks like you described.