Guest MM_280Z Posted June 8, 2002 Share Posted June 8, 2002 There is something weird going on with my R200 mount. In reverse gear, as soon as I give it any gas I hear a clunk and I lose all power to the wheels. If I am careful and don't apply enough torque to lift up the diff then I am fine, but with any significant torque applied the diff lifts and it is as if the driveshart is freewheeling and no power goes to the wheels. I (fairly) recently replaced the rubber mount to try to get the rear end to stop clunking, and now this problem has cropped up and gotten progressively worse. It is getting to the point where I can't park in a downhill facing parking space without fear not not being able to back out! Any ideas? As I said I replaced the rubber insulated diff mount to try to stop the clunking already. I wouldn't say it eliminated the clunking problem completely but it did lessen the effect. But now I have this "freewheeling" problem. It only happens in reverse. Has anyone seen this? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 8, 2002 Share Posted June 8, 2002 Manual or automatic? Jack both rear wheels off the ground and manually turn the wheels in reverse and forward and see and hear what happens or what developes Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 8, 2002 Share Posted June 8, 2002 How far into the transmission is the driveshaft yoke? If its just barely engaged I guess it could tear the splines a bit on the end? Could it be the driveline is to long? Maybe bottoming out in reverse? Just some idea's.. Regards, Lone Quote Link to comment Share on other sites More sharing options...
VRJoe Posted June 8, 2002 Share Posted June 8, 2002 I'm guessing that your driveshaft is backing off the trans spline when the diff lifts. It could be that your driveshaft is too short and the new bushing brought it to light, or the diff moved rearward somehow. Just a guess, but you can probably slide under and check the front yoke to see if that's the cause. -VRJoe Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted June 8, 2002 Share Posted June 8, 2002 Hard to imagine a diff letting power flow in the forward direction but not the reverse. There is no ratcheting assembly in a diff that I know of. Could be the yoke slipping out of contact, although I would think once this happens the odds of it going back in again are small. Another guess is you have a transmission problem. Get the problem to occur again and look to see if the driveshaft is turning or not (a mirror? Might want to get the wife to look underneath just in case to problem suddenly fixes itself ) Guess this won't rule out the yoke coming unglued, but it will eliminate the diff. Quote Link to comment Share on other sites More sharing options...
Mike C Posted June 8, 2002 Share Posted June 8, 2002 If yuu did an r200 swap on an earlier car(70-71) and kept the OEM driveshaft, it is too short. Unless something is REALLY wrong with the diff, which seems doubtful, it has to be trans spline engagement. You will break either the driveshaft or tranny ouput shaft sooner rather than later if that is the case. Quote Link to comment Share on other sites More sharing options...
Guest MM_280Z Posted June 9, 2002 Share Posted June 9, 2002 The trans is an auto and all components are stock, the only thing I did that I think could have affected it is the rubber mount replacement. Quote Link to comment Share on other sites More sharing options...
Mike C Posted June 10, 2002 Share Posted June 10, 2002 It could be your auto trans... Quote Link to comment Share on other sites More sharing options...
Georgia Flash Posted June 10, 2002 Share Posted June 10, 2002 I had this same problem with my 75 before I started to dismantle it for the V-8 swap. It went great in all forward gears, it had a manual 4-speed tranny, but sometimes it wouldn't engage in reverse. You could put it in 1st and roll the car forward under power a little and then try to engage it in reverse again and it usually would hook up. I was going to the local vo-tech school at the time (automotive class) and one of my instructors was a former transmission specialist at both a Nissan dealership and a Chevrolet dealership. He was certain that the problem was in the tranny. So we put the car on the lift removed the tranny and looked inside. He said that the reverse gears were worn. So about $230 dollars later I had the new gears from Nissan. Put the tranny back together, lowered the lift and fired up the Z. The damn thing wouldn't back off the lift! I was sooooo mad I could have taken a sledge hammer to the Z and my instructor who had assured me that the worn gears was the problem! I asked at the time if the problem could be in the rear (R200) and all the instructors said probably not. By the way we never did figure out what the problem was and I still have the old manual tranny with the new gears sitting in my drive that I will make a sweet deal on! Nissan would not take them back after they were installed Lesson learned! The hard way! Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted June 10, 2002 Share Posted June 10, 2002 I would suspect the trans or the driveshaft as well. I would also try some of that transmedic stuff you can get at autozone or whatever. I had an old turbo400 that used to slip sometimes, and transmedic always cured it. IF the stuff works for you, you have a tranny problem. It is a pretty cheap test. Good luck. Quote Link to comment Share on other sites More sharing options...
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