Something strange going on...

[patrickm1587]

I've got a 1990 240sx, just got a SR20 red top swapped into it a couple of days ago and got it running. It runs fine, there's nothing wrong with the way it runs, but there's something weird going on in the rearend. I don't know if the mount is broke or if it's actually in the differential. When I put it in reverse and let out on the clutch, it will pop in the rear. It won't do it when you put it in first and let out on the clutch though. Anybody got any ideas? I know the previous owners could have tore up the rearend since it had a different SR in it, but is there anything I can check? Drop it down and take off the cover?

Edit:
If it turns out to be the differential, what can I swap in there besides a stock diff?

[patrickm1587]

Seriously? Nobody has any thoughts or ideas at all?

[-RJ-]

A 95+ j30 rear end will give you a VLSD

Google is your best friend

[Gabes13]

Check the bushings before you do anything mechanical.

[Hoffman5982]

j30 would prbably be easiest to find if you're near a junkyard. 95+ will bolt in, 94 and below require the axles. and for the s13 you'll need the cover off your old dif

[patrickm1587]

What is a J-30? I'm thinking it's bushings or something like that. Does it have a rear end mount or is it just bushings?

[Michaelmoore]

Infiniti J30

[jazz4890]

A j30 is a differential from an infinity j30 car. That car has a differential that makes both tires spin together instead of the differential you have now that only lets one tire spin using the engines power. You should go to the junkyard and get that differential if your old one is worn out. As for the noise your car makes when you put it in reverse I have the same problem and I don't know what it is either. But it doesn't seem to affect driving in any way.

[costa_rican13]

I have a weird sound too but I also have the j30 diff as well..

[patrickm1587]

A j30 is a differential from an infinity j30 car. That car has a differential that makes both tires spin together instead of the differential you have now that only lets one tire spin using the engines power. You should go to the junkyard and get that differential if your old one is worn out. As for the noise your car makes when you put it in reverse I have the same problem and I don't know what it is either. But it doesn't seem to affect driving in any way.

Yeah I know, it's a LSD lol. I don't know if it's the diff. that's wore out or what, but it doesn't seem to affect the driving on mine either. It's got to be bushings or something.

[LoserCard]

Well you have an S13, so check to see if the differential you have in has bushings on the front two bolts holding UP the differential. If it does, then it is those. I swapped differentials and had to knock those out and put washers on top and bottom to hold it in place. S13 don't use any sort of differential bushings.

Oh yeah and it make that weird "clunk" noise.

[breadbox]

Get alu bushings for the diff. I plan on it whenever I'm going to mess with my diff next time.

[costa_rican13]

stance bushings for the win!!