Clunk, side effect or problem?

[Wingnutt]

I know there are a lot of threads regarding rear end clunk but apparently there are also lots a possible causes... so without further ado:


Ive installed a few urethane bushings or inserts here and there and I know that often comes with the side effect or adding additional noises or vibrations, and I just want to make sure that's what I'm experiencing and that I didn't screw something up..




I installed the Whiteline Rear Diff Outrigger Mount Kit
https://86speed.com/whiteline-rear-d...gger-mount-kit


To hopefully tighten up some of the slack in the drive line, it may or may not have helped, maybe some.. But what it did do ( I think) is introduce a really solid CLUNK when shifting (manual) gear doesnt matter, out of neutral into first etc etc... If Im very smooth and careful I can do it without the clunk.


It sounds ALMOST like a light backfire when shifting brrrrrrt *thunk*.. brrrrrtt. but its not.


So, if this is just the cost of doing business when running a diff inserts, then it is what it is, maybe Ill remove them. but if this is abnormal I want to know and ill see if maybe I need to double check my work.

Thanks for any help.



Side bar: Ever since Ive been on this forum Ive set up every thread that Ive made or posted in to "instant email notification" when there is a reply. I have never once received said email and no its not in my spam folder. I have to remember to check in periodically and look at all my posts to see if there are any replies. Just throwing that out there.

[radroach]

@Wingnutt referring to parts from the "positive traction kit", if you have the rear outrigger kit then you definitely need to install the differential and subframe inserts as well.
When I did my install, I only installed one part at a time the diff and driveshaft clunked like crazy until I put the rest of the kit in.

[NoHaveMSG]

Originally Posted by radroach

@Wingnutt referring to parts from the "positive traction kit", if you have the rear outrigger kit then you definitely need to install the differential and subframe inserts as well.
When I did my install, I only installed one part at a time the diff and driveshaft clunked like crazy until I put the rest of the kit in.

I had the opposite experience. The more I did, the louder the clunk. I have outrigger bushings, cusco diff brace, SPL solid subframe bushings. Modulating the clutch at low speeds I get a pretty solid clunk everytime from the backlash in the drivetrain. I get a clunk on upshifts too, don't notice it so much on downshifts.

[strat61caster]

Not normal, check to make sure everything is seated properly and fully torqued to the right spec. If you did not use a torque wrench were any of the bolts noticeably difficult?

I’ve got at least 45k miles on my diff and subframe inserts without odd clunks, removed the diff bushings on the ears to reduce gear whine about 10k in.

[euniqe]

I installed those diff inserts, and I hated them.

Made no noticeable difference to street driving, and every time I let out the clutch, and often when disengaging it at low speeds, there was a loud "thunk". Drove me mad. Having a more solidly mounted diff may have use in a high-performance application, but wasn't worth it for me. I have since installed the whiteline subframe inserts and called it good at the rear end.

[Compelica]

I have the positive traction kit, and later added the same rear diff outrigger diff kit and got the clunks after. However previous discussions were already mentioning it so I was well aware of what I was getting into. My previous car (not an 86) too had that clunk whenever the clutch was abruptly let off, with no mods.

You get some gear whine and some resonance as well, mine is at 3k rpm.

However I never understood where the clunk was coming from or why the clunk noise happens.

[NoHaveMSG]

Originally Posted by Compelica

However I never understood where the clunk was coming from or why the clunk noise happens.

Backlash in the diff and play in the CV's. Jack up your car, put the park brake on, put car in neutral, and turn the drive shaft. You get like a 1/4 turn.