Driveshaft clunking/Differential play...

[Paperboy415]

We'll I started hearing a clunking noise coming from the rear after some driving in the twisties...I almost shiiittted my pants thinking I must have tore my subframe or a bushing b/c it seemed like my car's rear was swinging. Maybe my imagination, but I remember race car handling prior to this unfortunate run in the twists. Anyways clunking sound comes on, but I can't quite locate when/where...during turns, accelerating...w/e I just hear it randomly.

Today I put it in the air...Look for subframe damage...Thankfully none, bushings still need to be replaced I think I ripped one or two which is causing the additonal roll/swaying from the rear portion of my car. Finally rotate the wheels and hear the clunk! When I turn the wheels there is play between the differential and the driveshaft which makes a clunking sound. Obviously louder the faster I turn the wheel. Which would mean harder the acceleration the harder/louder the clunk. We'll found one problem. A couple of the mechanics at my work were telling me that it is normal to have a little play there, but the clunking sound shouldn't be noticable in the cabin, so obviously I have a little too much clunking going on. They gave me a run down, but I want to know if anyone here has dealt with this issue before hand? I don't feel like replacing my differential...

Also...what are the main bushings that I want to replace in the rear...besides all of them...priority wise...rsm's are already done...as I didn't see anything obviously bent or loose in the rear. A bushing must be the copriet for the excess roll I'm experiencing in turns...

[PrestoMB]

Well I have a similar problem. I hear a thump or clunk whenever I shift and get on the throttle. I jacked up my car and snoped around. All my bushings were fine and there seemed to be no problems with the subframe. I have an LSD so I grabbed one wheel and rotated it forward and backwards, there seemed to be a lot of play and if I did it fast Iheard the noise I hear when getting on the gas. Evidently the noise is either extra play in the actual differential or the CV Joints in the halfshafts. I think it is the differential itself, so im going to be replacing it. As far as things that can be done while down there, you can do some reinforcements. TMS makes rear subframe reinforcements as well as Rear swaybar reinforcements. THere are 4 bushings that connect the differential carrier to the subframe. Then there a 3 bolts connecting the differential to the carrier. TMS also offers Solid aluminum bushings for the carrier to subframe, and they offer a kit for the differential to carrier bushings that consists of 2 aluminum and one delrin bushing. I wouldnt do either of those unless I did the reinforcements though. Good Luck.

[Paperboy415]

Yes! You are talking about the exact noise/play I am...I do have tms sways and the reiforcement kit, but havn't welded the tabs in yet. So it can be the axleshafts then? I do have 150k miles on them, but nobody really pointed to them as the copriete for the extra play. It sucks thinking everytime you go WOT your damaging your differential/cv axleshafts which ever it is. I have an LSD as well forgot to mention that.

If it is the differential that is allowing this play it will no doubt go out pretty soon under the conditions I like to drive.

Anyone know how difficult it is to actually replace the subframe bushings?

[PrestoMB]

Yeah the CV Joints at the outer edge of the halfhsafts can go bad and become somewhat "loose" and start making noise. I personally think its the play in the differential with the pinion and ring. I agree with you though that if it is the differential then it will be going soon because I like to launch/beat on it a lot . Because of this im planning on picking up a new/semi used 3.46 LSD w/ 40% lock-up .

[M3Cosmos]

Check your diff mounting bolts (all three, but especially the front one where all the stress is taken). I had one of these bend and another snap. I had the same symptoms... clunking at the beginning of any accelleration or decelleration. It's the easiest thing to check... just grab a (14mm) ratchet and turn. If it turns freely you might have a snapped one, or hopefully just a loose one. I've gotten to the point where I check mine everytime I change my oil. This is why the AA differential support bracket (DSB) exists. I think there is a group buy about to start up on this so check it out.
When mine was bent, I got it out myself and replaced it, but when the other snapped I had to have someone else get out the end that was stuck b/c I didn't have the tools; a little bit of a pain, but a lot less trouble than RSMs or anything else mentioned.

Josh

[PrestoMB]

I''l have to check that. I specifically looked at that bolt but didnt see anything wierd. SO it can still be in there looking normal and be broke in half or loose?

[Paperboy415]

We'll I havn't checked the differential bolts, but I think I found my problem why I have a "loose rear end"...Not subframe or bushing related. My rear left shock absorber bolt SNAPPED! It's barely hanging on for dear life. The one that anchors into the hub assembly/brake dust shield thing. I look at the right one and it's a goes straight through...look at the left one and it's bent like a half of this \_/. Anyways...looks like I'll have to tap it out b/c I had my rear shocks done just a week or two ago. Looks like they overtightened it! I had a buddy of mine do it for me at my work. **smh** I should've just done it myself.

[PrestoMB]

Check your diff mounting bolts (all three, but especially the front one where all the stress is taken). I had one of these bend and another snap. I had the same symptoms... clunking at the beginning of any accelleration or decelleration. It's the easiest thing to check... just grab a (14mm) ratchet and turn.

Update: Well got under the car in shop class and checked all the bolts out. Checked the 4 subframe bolts and 3 diff. bolts and they were all tight . Im really iritated at this and dont know what it is . Any other Ideas?

[danp412]

I have the same clunking sound coming from under my car, after inspecting it I noticed that my driveshaft is lose coming from the the transmission side. If I twist the driveshaft next to the flex disk, there is play. BUT If I twist the driveshaft from next to the differential there is no play. This makes me pretty sure that the play is coming from inside the transmission. All the bolts on my driveshaft are tight, and my flex disk is in great condition.