PETEW Posted April 4, 2012 Share Posted April 4, 2012 Hey guys, I have been working on my 240Z for some time now. I finally am getting it close to being done, and now I have a problem. Car is a 280 motor with a 5 speed, 300zx LSD differential that was redone using extra clutches bought here. I also have 280zx turbo cv's with Modern Motorsports adapters. I took my car out today for a short drive getting it ready for a trip to the office tomorrow. I have taken it out a few times before with one trip being a good 60 mile trip. Everything worked very well those times. Today was a different story, though. Today I took her out for a quick drive to get the oil circulating and warm the engine up. I was taking it easy shifting at low revs and just enjoying the car. The rear has a wine to it. I think the pinion bearing is bad. I didn't change it when I did the tear down and added clutches. Either that or the gears are not meshing correctly now. The drive was going well. I went a few miles on a state road just cruising. I turned right onto a side road and then made a left to turn around and go home. That is when i heard it. Plain as day a thump, thump, thump coming from the driver side rear. I finished the turn around and then pulled to the side of the road. I checked under the rear to see what was the mater. I was expecting to see the half shaft in two pieces or the exhaust touching the shaft somewhere. Nothing. I decided to drive slow and get her home. It seemed like it was going well till I had to turn left onto my road. Then I heard it again. Thump, thump. But I made two other lefts with no noise. I pulled the car into the garage and jacked the back end up. Nothing. Nothing loose, nothing broken, nothing touching. I am really at a loss here. Do the cv's hang up when they are stock length? Could it be something in the rear? I was thinking maybe the LSD acting up. I haven't driven it in a couple of months. From a visual inspection I see nothing. If you have any ideas, let me know. I am at a loss. I really thought I had this thing ready for the road. Now I am thinking I am running into another big problem. Please let me know what you think it might be. I am really trying to get this car on the road and put some miles on it. It's too fun of a car to have sitting in the garage. Thanks. Here is a quick pic of how the car looks now. Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted April 4, 2012 Share Posted April 4, 2012 Is there a metal on metal noise? Could be your wheel bearing. Quote Link to comment Share on other sites More sharing options...
NewZed Posted April 4, 2012 Share Posted April 4, 2012 Could be something in the tool bin behind the seat. Seriously. Quote Link to comment Share on other sites More sharing options...
beermanpete Posted April 4, 2012 Share Posted April 4, 2012 Perhaps the LSD locked while you were turning and caused the inside tire to hop a bit. Quote Link to comment Share on other sites More sharing options...
PETEW Posted April 4, 2012 Author Share Posted April 4, 2012 Is there a metal on metal noise? Could be your wheel bearing. The sound was more like something hitting something. I really thought my exhaust would be touching the halfshaft. But it wasn't. Could be something in the tool bin behind the seat. Seriously. Nothing loose in the car. But I will check again. Perhaps the LSD locked while you were turning and caused the inside tire to hop a bit. That is a possibility I thought of. It didn't do it before, but would the LSD get a little tight from not being used? I also was thinking the CV bound because of length. I know the driver side was tight getting in, but I never read anything about people shortening them when putting them in. I may have missed it, though. What really baffles me is that it didn't do it before. Thanks for the ideas guys. Keep them coming. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 4, 2012 Share Posted April 4, 2012 (edited) Clunk clunk clunk doesn't sound like LSD to me. Chatter is more of a bang bang bang. Wheel bearings are usually load sensitive, so the test is to swerve back and forth hard and listen for a groan. I don't think you'd hear a wheel bearing turning around in a parking lot, for example. If you want to check the CV length the thing to do is remove the springs and then push the suspension through its range of motion by hand. I'd check the stub axle, seems like some people get a clunk before it lets go all the way. It's kind of tough to identify noises on the internet though. Good luck with it. Edited April 4, 2012 by JMortensen Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted April 5, 2012 Share Posted April 5, 2012 (edited) Could you have just run over a line of reflectors, some of those little ridges to wake you up, or something else in the street? Could your front tire have been rubbing your TC rod? Could your front tire have been rubbing the airdam or flare? I've had my rear axles loosen at the wheel end of the flange - check that. Check driveshaft bolts. Have you added camber or caster - I get some funny noises on low speed turns from my whacked out alignment. Has your rear swaybar link nut come off and could your swaybar be hitting your axle in turns? Is your spare tire loose in the well? Please tell us when you find/solve the problem. Edited April 5, 2012 by RebekahsZ 1 Quote Link to comment Share on other sites More sharing options...
PETEW Posted April 17, 2012 Author Share Posted April 17, 2012 Hey guys, I wanted to give you guys an update. First off, it is the drivers rear that is clunking. I am not sure why I put passenger side in the title. Either way I jacked the car up and had a buddy over to listen. I put it in 2nd gear and gave it a little gas. There it was, clunk, clunk, clunk. The sound was lighter but it was there. My friend said he didn't hear it. Today I decided to take the wheel off and try again. The rotor made too much noise when loose, but the sound was similar. I then took the rotor off, and tried again. No noise. I tried higher rpm's, lower rpm's, it was all quiet. I then had my wife come out, so she could control the gas while I listened. I had her even put it in 3rd and get it up to 20+ mph. No noise. I then mounted the rotor and caliper again, and then the wheel. I had her take it to third again, and cruise with it. The car was quiet as a mouse. I am at a loss. Maybe the rotor was off a little causing a clunk. I also found a wheel weight on the ground (from that rear wheel). It wasn't buggered up, but it could have been bouncing around in there. Either way it is quiet now, so I am going to take it for a spin, again. Thanks for all the help. Quote Link to comment Share on other sites More sharing options...
ZT-R Posted April 17, 2012 Share Posted April 17, 2012 Where your lugs tight when you took them off? Caliper mounting bolts tight? I have seen caliper mounting bolts loose and make clunking noises. Even if they are snug they will do it. Make sure they are tight... Quote Link to comment Share on other sites More sharing options...
PETEW Posted May 16, 2012 Author Share Posted May 16, 2012 Here is another update. I have been driving the car and the clunking came back, and is now doing it more frequently. I have a feeling the inner CV is shot on the driver side. Either that or something bad is going on in the differential. Either way it is coming out and I am going to go over it all. I will report with the good or bad. Thanks. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 16, 2012 Share Posted May 16, 2012 I just did the 6-clutch LSD upgrade. I'm banging just like you. Do you know if your LSD is stock? At the advice of the forum, I'm changing my gear oil to 80W140 and adding 2 tubes of LSD additive. First try, I'm gonna leave a little room in diff, so that if it still bangs I can add a third tube of additive before topping it off with ger lube. It feels like I have a flat tire, or loose lug nuts only when I do slow, tight turns, but I don't have any loose parts. It sounds like it is from the passenger side tire most of the time. From what guys are telling me, we must have LSDs that are too tight. I'm either lubing it up or pulling it back out to remove shims. Quote Link to comment Share on other sites More sharing options...
brianZortiz Posted May 17, 2012 Share Posted May 17, 2012 I also did the 6 clutch LSD upgrade and was shimed to around 40-50lbs. I have a bang while turning, I checked everything and it ended up being loose u joint to stub axles nuts. It stopped the bang, but u joints snap so are bad. I need to replace. Quote Link to comment Share on other sites More sharing options...
PETEW Posted July 24, 2012 Author Share Posted July 24, 2012 Here is another quick update. I found out the inner CV is shot on the driver side. I have both Shafts at a shop that rebuilds them. If they do a good job I will let everyone know there name so they can use them if they need them. Not too many people working on 280zx CV's anymore. Since I am doing that, I figured I would do a rebuild of the rear (replacing all bearings and seals). Anyone have any recomendations? If not, I guess I could just buy oem from Courtesy. Thanks for the help guys. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 24, 2012 Share Posted July 24, 2012 Suggestion - don't rebuild the diff. If you want to put new seals in, all you do is pry the side ones out, pull the pinion nut and pry that seal out, replace, red loctite the pin nut and make it RFT (torque spec is something like 130-200 ft/lbs). You can pull the cover and reseal it too with some silicone. If your bearings aren't bad though, the replacement bearings are expensive and you won't get any benefit from it at all. Take it from someone who has been there and done that. Rebuild on an R200 is a waste of time IMO, even more so on a common ratio, where you can just go buy another good used diff for $150. Quote Link to comment Share on other sites More sharing options...
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