oadriver Posted May 7, 2009 Share Posted May 7, 2009 Please help. I have an 86 Z31 NA with an R200 diff. This is not the normal clunking this is experienced when when a diff mount goes. This continuous loud thumping seems to be coming from the differential and is directly propotional to the rpm's. It only occurs when I have my foot on the gas. I have eliminated the driveshaft and the diff mount. The funny this is, it only "appeared" after replacing the crossmember bushings with poly ones. If anyone has experienced this before, I appreciate any feedback. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 7, 2009 Share Posted May 7, 2009 Sounds like something is bad wrong. You're probably going to have to pull the diff and take off the cover to figure it out, but driving in a straight line indicates ring and pinion problems. The other one that comes to mind is the cross pin shaft backing out and hitting the case, which we've seen with several drag raced Zs over the years. Quote Link to comment Share on other sites More sharing options...
oadriver Posted May 7, 2009 Author Share Posted May 7, 2009 I thought it might be the ring and pinion gears. Are these replaceable? Quote Link to comment Share on other sites More sharing options...
Challenger Posted May 7, 2009 Share Posted May 7, 2009 Wouldnt being on the gas change the angle/position of the diff/driveshaft and possibly cause interference? Is it proportionate to SPEED or RPM. That makes a big difference. Quote Link to comment Share on other sites More sharing options...
oadriver Posted May 7, 2009 Author Share Posted May 7, 2009 Interference with what though? Quote Link to comment Share on other sites More sharing options...
oadriver Posted May 7, 2009 Author Share Posted May 7, 2009 it is proportianate with speed but only when I am applying the gas. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 7, 2009 Share Posted May 7, 2009 I thought it might be the ring and pinion gears.Are these replaceable? Yes, but it's far easier and cheaper to just buy another used differential and swap the whole thing out. Some diagnosing noises links: http://www.ringpinion.com/ContentFrame.aspx?FilePath=Content%2fHowTo%2fGeneralInfo%2f%2fDiagnosing_Noise_(Part_1).inc http://www.ringpinion.com/ContentFrame.aspx?FilePath=Content%2fHowTo%2fGeneralInfo%2f%2fDiagnosing_Noise_(Part_2).inc Quote Link to comment Share on other sites More sharing options...
oadriver Posted May 7, 2009 Author Share Posted May 7, 2009 Thanks Jon. Randy's info is helpful. Have you had issue with trying to get the cover off of the R200. I tried it over the weekend, without actually pulling the diff, and had a heck of a time. Couldn't actually get it off. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 7, 2009 Share Posted May 7, 2009 Uh... the diff attaches to the car via the cover. You need to take the diff out before you can take the cover off. Quote Link to comment Share on other sites More sharing options...
oadriver Posted May 7, 2009 Author Share Posted May 7, 2009 hehe. I forgot to mention it was being supported by only the jack and still bolted to the crossmember. The mount was completely out. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 7, 2009 Share Posted May 7, 2009 After you get all the bolts off you might have to pry the cover off. Try smacking the cover with a rubber mallet. If that doesn't work then try to hammer a thin chisel or screwdriver in between the case and cover to separate. Quote Link to comment Share on other sites More sharing options...
oadriver Posted May 7, 2009 Author Share Posted May 7, 2009 Cool. That is no problem. I will be dropping the diff completely out soon to take a look inside. I think a pinion gear tooth in shot but will find. Do you know of a place to find a good used diff? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 7, 2009 Share Posted May 7, 2009 Junkyards, classified ads at sites like this one. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.