labrat Posted February 28, 2002 Share Posted February 28, 2002 Okay, i've been investigating the clunk from my rear end, and have some questions for those of you who know these systems intimately. I have an 81 ZX with a clunk in the rear when i shift into drive, drive to reverse, or when i slowly pull out from a lite (brake barely on). Sometimes hits on the 2-3 shift, too (i think 1-2 is just too fast to feel it with the shift kit). I jacked the car up and with the e brake on, the driveshaft has about 1/8 inch of rotational play. drivers side halfshaft is solid, no play at all, but passenger side has about 1/8 to 1/4 in of play. My question is this: would the play be coming from the diff itself, or possibly some kind of slack in the hub assembly on the passenger side? the halfshaft will rotate slightly with the ebrake on, which doesn't seem right. Is there anything in here to get slack? I know it's not the ujoint, the entire shaft slips. Thanks for any heads up on this one! (I just don't feel like taking it apart to see....) Bill Quote Link to comment Share on other sites More sharing options...
DavyZ Posted March 2, 2002 Share Posted March 2, 2002 bump Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 2, 2002 Share Posted March 2, 2002 There are so many joints back there. I once had a stiff u joint that was making a lot of bumps/thumps when running but jacked up for inspection ,it was the tightest of all. Check again and pack a lunch. I have a bump in the rear of my project car and I am waiting for it to get serious before diagnosis because I can not find it now. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted March 2, 2002 Share Posted March 2, 2002 The driveshaft will always have a certain amount of looseness in that it can be rotated a few degrees each way due to clearances in the pinion and spider gears, as will the u-joints. A wornout u-joint is best found with it "unloaded". So you will need to place the car on a flat surface, take it out of gear so that all the drivetrain is un-stressed, and then start pushing and pulling at the joints. I've always found this to work better at finding the bad joint than twisting the shafts. Don't forget to inspect the front diff mount too. Quote Link to comment Share on other sites More sharing options...
pparaska Posted March 4, 2002 Share Posted March 4, 2002 Agreed Terry. It also helps to put the tip of your finger between the yoke that's welded to the drive/halfshaft and the yoke on the same u-joint that bolts to the diff, companion flange or the slip yoke at the trans. That way you can feel very small movements between the two parts to diagnose a bad u-joint. Look for rusty dust around the seal of the cups too. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted March 18, 2002 Share Posted March 18, 2002 Had a similar problem some years back with my 70 240. Ditto on checking the front differential mount (my problem the first time around) but don't overlook the obvious: check all the rubber pieces and make sure the mustache bar bolts are all torqued to spec. Quote Link to comment Share on other sites More sharing options...
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