OK, so I got the car back together and went to drive it. There is a ticking noise coming from the rear somewhere, whether in gear or not. I put the car on jackstands, turned it on and put it in gear, to see if I could locate the sounds. Couldn't hear anything, but my left wheel wasn't really turning. Every second or two it woud rotate a tiny bit, and if I turned it with my hand, it felt like it wanted to go. Plus, the ticking noise is much louder when turning right, and almost nonexistant when turning left.

When I was removing the left rear strut, I forgot to unbolt the axle from the hub at first. Is it possible that I pulled the axle partially out of the differential when I did this?

Also, when up in the air and car turned off, in neutral, spinning one wheel does nothing to the other. In gear, they spin opposite directions, which I believe is normal.

Whatever the problem, I don't think I'll have it ready for my planned track day next sunday.

If the diff in question is a R-200 it is possable that the hub has been pulled out slightly . I don't know if the clicking would be from this . The clicking could be from a ujoint or a axel bearing that is going bad. I had a ujoint on a half shaft do the vary thing you a describing . Gary

If the diff in question is a R-200 it is possable that the hub has been pulled out slightly . I don't know if the clicking would be from this . The clicking could be from a ujoint or a axel bearing that is going bad. I had a ujoint on a half shaft do the vary thing you a describing . Gary

Its an R180, but I think its actually the axle, since the side flange for the diff is bolted on. I felt something give when I was pushing down on the control arm with the axle still attached.

MANY THANKS ... Beandip !!!!!!

I searched the site, resurrected this older post as it helped me get through a strange noise from my rear end.

My Sceanrio: I have never had wheel bearing are differential noises before. Anyway after I completed installing new coils and shocks on my 1973 240z and was anxious to test drive it! I also greased the U-joints along with the other front end fittings as typical maintance for winter storage. I finished the job, test drove the car and when turning left I hear an almost grinding noise from my rear (right side). Went back home, I checked all the drive shaft bolts - all are secure - tested it again and the same "grinding" noise from my right rear when turn left??

Found this link and did the following on my R200 differential:

1st) Drained my differential, the oil was terrible, very black and thin, no real viscosity felt between my fingers. I did find a one metal sliver on the plug and could see very small metal specs on the rag used to clean the plug under bright lighting. The plug debris wasn't terrible as I've seen this before. The sliver looked new - most likely from my recent "grinding" test drives. I let the oil completely drain to get as much out as possible.

2nd) Refilled the differential with Royal Purple 75W90 since it's supposed to be great stuff. Also a lot of positive words in this website. With the car up on jacks and the 5spd in neutral I rotated the rears - they turned freely and smoothly. No slop in any U-Joints or anything out of the ordinary. I also put the 5spd in reverse and turned the wheels - nothing strange here also. Rotated one and the other side rotated in the opposite direction smoothly.

3rd) The TIP from this original link above .... Lastly - using a 3lb mallet and socket extension, I tapped the differential drive hubs "INWARD" toward the center of the differential thinking maybe I pulled them out a bit when I replaced my rear shocks and coils. I did this about four(4) times on each side hard enough with a 1/4 swing of the mallet. When finished - rotated the wheels to assure no strange grabbing or noise - all was smooth.

Then test drove the car and the noise was gone. The rear end almost seems quieter as well, maybe it's me? I'm thinking the New Oil (especially Royal Purple) along with tapping the drive hubs - may have un-stuck the slip plates?

I was all ready to line up a wheel bearing replacement job. and maybe I will have to in the future, but for now it seems fine and I'll watch this. Right now the car is winterized and will have to wait for spring - since it's pretty cold (20F) and snow coming.

Anyway - this link and website was a huge help. Thanks BEANDIP !!!!!!!!

Edited December 19, 200915 yr by moritz55

Unless you have a limited slip differential there are no slip plates, only spider, ring and pinion gears. Odds are that you pulled the diff side flange out a little when changing the strut inserts, and the splines on the shaft were not properly engaging with the side gear in the diff, and thus causing the sound you heard. This would also explain why you heard it when turning left.

I imagine that the spider gears were probably rotating furiously while the side flange was disconnected from the right side, and these gears are the ones that wear the most in the diff. Hard to say of the shavings you found were due to this or just normal wear and tear over how ever many mile that R200 has seen over its lifetime. I can tell that look pretty bad in the R200 I have with over 300k miles in it. Sadly, there doesn't seem to be any replacements that I can find. Looks like an LSD is in my future since this will eliminate the spider gears.

Edited December 19, 200915 yr by =Enigma=

Thanks for the response Adam. My R200 differential has about 80k miles on it as it was pulled from a 1982zx. I'll keep and eye and ear on it...

I did take the car out this past Sunday for a 15mile run, city and highway and it ran quietly. Real smooth even with the 25F temperatures, no snow .. just cold and dry conditions.

Many thanks ...