Clunking in rear during shifting and not the diff mount (searched)
 

Well I recently dropped the entire rear subframe in my 86 sport, I installed the following:

Rear LCA bushing
DTSS bushing
Mazdaspeed front diff mount
MMR front and rear subframe mounts
4.1 clutch type lsd

Note-before dropping the subframe there was no clunking, noises, hiccups, etc in the rear end.

After I was done I went for a test drive and it started clunking during shifts. I went back and retightened the front diff mount (usual suspect), also retightening the subframe/rear diff mount areas (possibly too much, because the rubber crown for the rear diff has been smashed in, heh)

While driving I made the car jerk and buck around, it sounded much worse and sounded almost like something was "loose" but my diff mount is secure, driveshaft was good before the swap, diff/subframe mounts on, etc. I know Ddub took it to a rear end shop and it ended up being the diff itself, but this sounds more external.

Thanks

-Andrew

sounds like you forgot the 2 dif bolts and its hitting. if you are sure you put them in. make sure you got washers in there and its tight. just have somone look under the car. hold the brake, put it in gear and let out the clutch and see what moves

Which 2 diff bolts? the ones that go from the diff mount- diff? i did all those.

the ones that go from the diff to the cross member

Diff- crossmember? Eh? you mean subframe? Yeah I thought that was it so redid it.

sub frame is what i was thinking but must have typed something else. i put bolts on my friends and tightend them all the way down but it still wasnt holding so i had to put washers

Anyways that was what I retigtened, I even shook around the subframe/diff for movements and none? Still no clue...

Loose rear shocks.....somehow??

go under the car and pushing up on the tail of the rear end where the drive shaft connects. push up hard and see if it slams down. i have put nuts on there hella tight but still didnt do any good without washers

I'll check.


Will do, my friend is coming down right now to help me figure this out, i'll post the results, take some pics maybe the picture will come up with something? Thanks

-Andrew

Shook it all as hard as i could, nothing. There was very very minor play on the lsd pumkin where it bolts to the halfshaft, is that ok?

Here's something you might try but you need two people and BE SAFE while doing it.

Jack the rear end of the car up. Start the engine and put it in gear, say second gear. Have the second person watch the rear end from a safe place while you lightly stab at the brake pedal with the the car in gear and engine running. Maybe he can see what is moving and making the clunk noise.

When you jack it up you have to use somethig other than the pumpkin to jack it up with or it's a waste of time.

We were thinking of something along the lines of that, wheel chocks in the front tires, jack stands securely placed trying to make it as safe as possible but we ran out of time. If I made a video of my driving it and purposely making the car buck and jerk could anyone be able to possibly figure out what type of noise its making?

Just got back from the frame shop, they drove my car, looked under it and came up with a few conclusions:

1- The car is too low, which is causing too much camber causing the halfshafts to "stretch" not allowing play and binding which therefore makes the clunk
2- Something might be binding up, loosin main nuts and shake it to possilby unbind something

Any thoughts??

Not even a comment?

i dropped my subframe/lsd 2 weeks ago and had the same problem. first problem was that the two bolt connected to the subframe popped out while i shifted hard. there is supposed to be a flat piece of metal that goes on the bolt before the nuts go on. i wasn't paying attention when i took it off but i fixed that. if your using just washers, are they staying in there good. it might be twisting (one bolt goes up then down, or the likes).
the second thing is that my driveside half-shaft is shot (at the cv joint--i think that's what its called). my car is kinda low too. still need to get that fixed. i need a day without rain.

^Yeah i just talked to sonik rat about that little metal plate, i have the plate in but he said a tab goes on the "W" part of the subframe that the studs of the front differential mount slip into and locks it into place, I need to check that out tommorow.

I have the same problem in my 86 sport also. I think i might try these suggestions out.

yea, you can feel for that little tab. its at the top center piece of the subframe (in the respect area). good luck.

Will do tommorow, its such a pain, i hate clunking :mad:

https://www.rx7club.com/attachment.p...hmentid=148612 heres what i rigged up, look right?

yea, looks good.

interesting, i have a slight clunk in my car aswheal ill try this.. verry helpfull..


Gil

i have a solid diff mount and mine started clunking after while of driving with that mount. found out the tab got bent up after heavy launching and even though the nuts were tight, it would flex up to the bent tab and hit the underside of the body. i went a head and fabbed a metal solid snubber to go between the diff and the body.

hey guys, i have had the same problem in my 88 turbo vert, ever since i got it.

When i bought the car, this clunk was the only thing that concerned me. I figured it was the transmission.....and months has gone by, and i still have this clunk when i shift, as soon as i release the clutch, it clunks and bucks for a second then its good til next shift.

so more than likely, i need to fabricate the tab that goes on the "W" part of the subframe that the studs of the front differential mount slip into and locks it into place?

is it causing any damage by doing this? I'm just asking for the heck of it, but i'm getting mine fixed asap cuz its really annoying and makes your car seem like a piece...