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View Full Version : Clunk From Rear on Clutch Release/Engagement



GrannysBird
05-24-2013, 10:20 AM
So I finally got tired of peg legging it and replaced the worn clutch packs in my TC rear end before I headed out from here in Illinois to Philadelphia Pa. I rightly assumed that the road trip would be much more enjoyable with the traction lock working and as a pleasant bonus the hitherto clunk on depressing the the clutch pedal had disappeared for the first hour of driving on the highway.

Great I thought, I've got two wheels spinning and without the clunk and slop this bird drives like a brand new car. Much to my chagrin however, the clunk quickly reappeared some time between that first hour and Indiana...

Keep in mind the clunk only happens when tension is let on or off of the drive train by way of the throttle (or more noticeably the clutch), and direction ( ie turning or going in a straight line) has no effect on worsening or altering the sound. There appears to be to my and my co pilots ears' no chattering from the clutch packs in the rear.

What bothers me is the fact that the clunk disappeared initially after installing new steels and clutches, but quickly reappeared after only a short time of only highway driving (and straight as straight here in Illinois). Maybe it's coincidental that the clunk reappeared or a new one appeared after fixing the traction lock, but either way I'm open to suggestions so that before I tear into this thing I can dive in with some idea of what's going on.

The driveshaft is new as well as the ujoints, but that will be my first checkpoint. The posi is still working as I tested it out last night under "working" conditions on the road. There is no whurring sound and the ring gear did not raise any alarm bells upon dis-assembly of the center section, so yeah..

Haystack
05-24-2013, 06:54 PM
I'm betting on motor mounts or u-joints. I replaced one with an autozone "gold" one. about 15k later and its getting a bit loose.

using stock third/cougar motor mounts?

GrannysBird
05-25-2013, 03:22 AM
I've got Chuck w's mounts, up front and I'm running a brand new polyurethane transmission mount on a solid mounted transmission crossmember so yeah. I'm currently waiting for the garage to clear out so I can get the thing up
in the air and checked over with a fine tooth comb. Academically however I'm pretty stumped at the minute.

87thunderbirdBlackJack
05-25-2013, 06:15 AM
Pinion bearing is taking a dive.

87thunderbirdBlackJack
05-26-2013, 12:23 AM
No, but if the bearing is toasted it gives it enough slop to sound like the backlash is all out of whack. Not saying I'm right by any means, but if you're hunting for the problem check all angles. The 8.25 rear end in my 92 dakota had the same problem checked everything, pulled the driveshaft to check universals and the pinion had a ton of play in it.