clunk from welded diff
 

So currently I'm running a welded diff. Everytime I shift, there's a loud clunk coming from the rear once I give it gas. If I shift and don't give it gas, just kinda let it coast, it won't clunk. Also, I get this loud clunking around tight/slow corners in addition to the normal chirping of the tires.

I'm concerned because my car was originally automatic and ABS. When I got the 5 speed done, I have no idea whether they used the ABS driveshaft or not. Would this affect anything?

a welded diff is rough. some cases it also depends on how it was welded too. most people just weld the spider gears without taking it out ofthe pumpkin, doing such the heat of the welder can destroy the bearings and just cause the diff to crap out.
For second hand experience, I had a friend who ran a welded daily and they guy who did it for him just left it in the pumpkin and went to town with the welder, it immediately whined like no other, and made noises like rocks were being thrown around in the back. about 6 months later, the spider gears just detonated.
The loud clunk could just be the force of the welded trying to turn the wheels over when under load.

yeah that loud clunk you hear around turns is just the general nature of the welded doing its job. As far as the clunking sound goes, it sounds like it may be shot bushing in the subframe or for the actual differential.

the diff was taken out of the pumpkin, cleaned, and welded by max parts in san diego so i think the spider gears will be fine. thanks for the quick replies!

this really sounds like bad rear subframe bushings. friend of mine had the same problem. it also clunks wen downshifting also right? if so thats my guess. sounds just like his did

I just installed poly subframe bushings in my s14 and also got my diff welded and it also makes this loud noise when reversing or shifting weight or anything. But i know its not a bad noise haha.

You should check out your subframe and make sure everything with the install is correct.

so i guess the general consensus is subframe bushings. damn that's a bitch. would getting new inserts/collars make it better or worse?

It will probably make it louder haha.
But whats your idea of better?

new bushings or collars will stop it from clunking..

Also check the mounting of the diff. Lie under the car and push up on the diff to see if the diff itself is moving up and down.

It's your subframe.

Proper way would be to install subframe bushings.

But you can fix it for the most part with subframe collars.

by better i mean i just want the clunking to stop. i went under my car today and moving it vertically but it's really solid. even tried moving the diff with a jack and it wouldn't budge. i'll install new subframe bushings one of these weekends then. thanks guys

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10000000% agreeeeee.

my car did the same i just installed Kazama sub frame spacers and presto no more clunking thumping noise

just wondering, my tranny grinds sometimes if i shift when im turning at low speed, like i can feel the vibration from the rear end through the shifter. Is this normal for welded diffs?

let us know if the bushings fix your prob...im getting my diff welded in my convertible, and im looking to troubleshoot before i even start