New here! Could use some help. Clunk in diff.

[ThatGoldS14]

Couldn't upload the video here. But here a YouTube link
https://youtu.be/IK28w9CjpEs

Just had the diff service and adjusted filled with redline 75w-90
CV axles checked and service new hubs new bearings new sub and diff poly bushings new comp clutch and flywheel. I have a solid driveshaft on the way.

EDIT: also have new trans mount and engine mounts installed new carrier bearing and still have the stock driveshaft in while waiting for the new one to come back.

Diff is a open case with a j30 vlsd in it.

What causes it, reverse and 1st mainly no noise in neutral or when you push the clutch in. Coasting At 4th gear doing 40 it vibrates from the rear end and same at 3rd and 30.

Thanks for any help

[brndck]

better check the driveshaft, I have a feeling one of the u-joints is on its way out, or possibly the center carrier bearing

since you already have a 1pc on the way, that will help you a lot in troubleshooting

when you say you had the diff service and adjusted, what did they adjust?

[tb13]

I can't watch the video because I'm at work, but seeing as you said it is a J30 diff in the factory case, is it shimmed properly? When I swapped my diff I flipped around the shims on accident, it made some awful noises on my bench, swapped the shims and everything was perfect.

Like brndck said, check your driveshaft. If your carrier bearing is torn or cracked, thats probably your issue. Once the carrier fails the driveshaft can flop around and cause the u-joints to fail leading to all kinds of awful noise and vibration.

[ThatGoldS14]

Forgot to mention new carrier bearing is installed..
The diff was adjusted to I think .005 from .016 it was barley out of spec and I bought the driveshaft from the driveshaft shop and the sent me one that was a half inch too long. I forced it in just to see if it fixed the problem but it still made the sound. Same as the video. So now I'm waiting g for them to cut and renturn the driveshaft....How could u send one too long s14 non abs is the longest driveshaft in 240sx...

[[240sx]]

Seems like clutch chatter (not saying that it IS, just what it reminds me of). Also, did you stall on purpose?

Sorry for contributing nothing.

Sent from my SM-G930P using Tapatalk

[ThatGoldS14]

It makes the sound the best when going up a hill and letting the engine struggle so no it wasn't on purpose but I was riding the line to get it to do the sound

[Wookie384]

How long have you had the clutch? Did the noise start after the clutch was installed?

[ThatGoldS14]

Clutch was installed 3 weeks ago...Noise has been there since I purchased the car it has only gotten worse the more things I fix. Poly bushing made it louder new clutch made it louder suspension I'm not sure if it made a difference but it continues to get worse.

[ThatGoldS14]

So one thing I just realized is that before I changed the clutch it still did this but it was more occasional. Now I have to try to make it not do it. The old flywheel had chatter marks on it so that was the issue before now it's worse so I'm assuming I installed the clutch wrong. Everything points to clutch chatter. Anyone have all the torque specs for flywheel pressure plate ect?

[Kingtal0n]

any vibration that changes when accelerating or decelerating is the hallmark of an improperly set pinion angle. The angle of the transmission U-joint needs to be identical to the angle of the differential flange (U-joint), identical but opposite ( "equal but opposite") And this can be an easy mistake when using a single piece driveshaft, in my opinion. It could just be a bad transmission mount (so test or check the trans mount).

In the IRS car like 240sx I found the differential around 0* or perhaps 0.5* angle up. So stick an angle finder ($5 harbor freight) on both U-joints and measure the angles to compare them. You should try to do with the car on all four wheels (not jacked up) but if you are careful you can also do it jacked up (if the u-joint is flat with earth I think it will work)

[ThatGoldS14]

Guess it's kinda a nooby error but there isn't a problem at all. after hours of research and asking people for advice because it was killing me.

Here's what happened there was a problem with my old clutch set up the previous owner ever let me know that the flywheel probably wasn't torqued correctly before I bought it. So I changed the clutch kit to the white bunny 6 puck upgrade because I plan on a turbo upgrade in the next year.

When I uninstalled old flywheel it had plenty of chatter burns and hot spots on it. so I thought bingo found the issue as I took the bolts out some were almost finger tight and other torqued down hard...no loc tight to be seen. Then I install my new 6 puck clutch flywheel all torqued and ready. I get in the car and bam similar issue but it's not a issue it's how 6 puck clutches are they freaking grab and will make your car jump and kick especially upon breaking it in. I've drove 800 miles and it seems to have gotten a little better but 500 miles were a round trip so I'm not sure if it's 100% broke in.
Anyways I've seen so many post of people having the same issue and no one ever gets a answer so hopefully this sheds some light for people. Mine just happen to be uninstalling a problematic clutch and installing a clutch that will make ur car buck a bit.

Here's a link with people having simar issues
http://www.ka-t.org/forums/viewtopic.php?t=58876

[ThatGoldS14]

Problem solved just happened to be when I uninstalled the old clutch because of a improperly torqued flywheel there were chatter burns and hot spots on it and the bolts where loose and some where tight as hell no loc tight. I thought bam there's my issue ...installed new white bunny 6 puck upgrade and it has a similar effect because it grabs like hell. After it breaks in a little more should be better. Just have to relearn how to drive with a puck clutch. I had no idea that the puck style clutch would make it kick a bit and buck. The video is way intense from how it normally acts I was forcing it to do it as bad as I could to see the extremes of the bucking.

As for the vibration I'm pretty sure the 1 piece driveshaft should solve that as the shop o took it too a month ago said I had 2 bad u-joints. (I'll update when I find out)

So pucks bucks and solids are smooth!

Here's a link from others having the same issue
http://www.ka-t.org/forums/viewtopic.php?t=58876