wheelerz31 Posted June 18, 2015 Share Posted June 18, 2015 Hello everyone, just wanted to start off by saying thank you to all who contribute to these posts. Your experience and advice have been very helpful in the past. So I have done my research and homework on this so far and I know there are more than enough posts on this issue out there, but I have replaced/refurbished just about all of the usual suspects up to this point. I'm hoping to get some more ideas to help resolve this for myself and hopefully offer some help to anyone else who is in a similar situation. Basically the problem is similar to what many others have described as a clunk whenever I get on or off the throttle in any gear and more significant whenever I engage the clutch from a stand still. It is particularly noticeable when going from reverse to drive. Here are the details and list of work done... '87 300zx Turbo 5spd (w/LSD) 190k Purchased about a year ago from a guy who owned it since 89. It had this clunk when I bought it. Since then I have done the following: -Replaced subframe bushings and mounting brackets -replaced rear shocks with KYB -replaced rear upper and lower spring insulators -all polyurethane control arm and sway bar bushings -new OEM diff mount -PO had the prop shaft replaced about 5yrs ago (less than 20k miles on it) - trans mount was replaced at the same time -lastly, I had the diff rebuilt with all new bearings and seals. (front seal was shot, also had a distinct whine while coasting) So I have a couple videos I took that show the amount of play in the rotation of the propshaft from the transmission side and the diff side before the car starts to move. Also, I don't think it's the ring and pinion backlash, because I asked the guy after he rebuilt it and he said it was fine, I think I remember him saying 0.007, which I know is on the high end of the spec, but its still far less than what I'm seeing in the driveshaft rotation. https://www.youtube.com/watch?v=dIAvunygQwg https://www.youtube.com/watch?v=BMs-a2yyK1g https://www.youtube.com/watch?v=74b1X_2XtbY I have seen other posts suggesting that there is the potential for slack in the spider gears or the cross pin shaft. I have to admit my understanding of the internal workings of a differential is limited so this is where I could really use some help from someone with more experience. From what I understand its normal for the spider gears to have some play in them, but I have also seen someone suggest that the gears can get worn on the outside of the carrier? The FSM has a spec and thrust washers to adjust the clearance between the "side gear" and diff case, but I'm not sure if that is the same thing and I also don't see where the LSD uses thrust washers at all or even shares the same spec. So again, I am a little outside of my knowledge base here. One last thing just to put all the info on the table, after I got the car I topped off the diff fluid (because of the front seal it was about a half quart low) and after doing this I noticed a chatter when turning hard like into a parking space. To be honest it sounded more like it was coming from the tires, but the FSM says some chattering can be expected after a fluid change so I didn't think much of it and also knew I would be getting it rebuilt soon as well. So that’s where I am, I know there are many possible causes of the clunk, but hopefully someone can offer some direction here and maybe this will also help others who have the same issue narrow it down for themselves. Thanks again for all your help! Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.