Cavernkid

I have a question about my 1987 RX-7. It has a weird Clunck in the rear end when I shift sometimes what could it be? It is very annoying plus i dont want something to break and tear up everything when it could be an easy fix.

DC350

hey, i've got the same problem.....Might be the diff mount. But i'm not sure

Cavernkid

i am just hopeing it is not the Halfshafts Those things are 100 bucks a piece

RX7_ZRO

Are you sure it's not pop instead of clunk? I thought there was something wrong with my '89 Vert because past a certain RPM, it would pop...found out it's just a good old Rotary feature.

If it's clunk, I'd have to say that it's probably a diff mount, although I'm speaking from guesswork and reading, not experience.

rx-7fc

it should be the diff mount broke

Rotorific

iTrader: (1)

It could be either a differential mount or your upper strut mounts that tend to go clunk when you shift because of the weight that shifts when you change gears

journey

My car does the samething, but normally only when downshifting to Accelerate. There is a definate clunking sound, and it comes from behind me, twords the rear center of the car.

What i would like to know is what should i look at to see what it is? I have a hayne's manual for my car(89 GXL), would it be in there? I'll start looking later. If its in the FSM i could also download that, if someone would give me a rough guess where to look

Any help would be appreciated, i haven't worried about it too much, but if the diff mount is broken, or anything else, i imagine that would bea bad thing.

Erik

TRURX7

I have the same clunking problem. It happens mostly when I go into 1st gear and if I am not carefull into second when I let the clutch go hard. If I take it easy on it, it does not happen, BUT WHO DRIVES IT EASY???

Someone give us a heads up on this please. I think it may be some kind of differential mount because the clunking seems to be centralized. Are these difficult to change?

Thanks
TRU

Detriuch

iTrader: (1)

thats either your differential mount or maybe your u joints. most likely mount. my old 86 base did the same

scathcart

Try rev-matching upon your downshifts, and let me know if it still clunks.

Try giving a hard launch and listen for the clunk.

scathcart

Front diff mount, cheap part (get the stiffer competition mount ~$40 I believe).

Labour intensive job, basically invloves dropping the entire rear-end assembly. Not so bad if you have air tools, but give yourself a weekend.

BlackTurbo2

beat me to it!!! haha I just had the same problem, and I replaced my front diff mount wih the competition one, but **** it cost me $99 from mazdatrix!!! I wanna know where you can get em for $50???? It was a bitch let me tell you, If you have a whole day with no distractions you can get it done. I also went ahead and replaced the 2 rear mounts since I was there. Ohhh does it feel nice now!! I hate that clunking!!!

Let me know where you get em for $50!!!

Jimmy325i

I welded my mount for free... Sounds like the problem though. jacking the car up in the rear you should easily be able to tell if its broken or not. The nose of the diff will wiggile up and down. (shouldn't move at all)

Don't sweat this job too much. All the steps are easily performed but time intensive. Replacing the mount only involves removing the front subframe supports and then lowering the subframe down. It'll still be suspended by the center link and hold itself nicely in place. If you have access to a hoist, USE IT! Well worth the beer it'll cost you. My friends dad has a shop with an old in ground chasis hoist, and we swapped the whole diff in less than 3 hrs. (LSD's kick ***!)

Spraintz

iTrader: (1)

yeah, what everybody else said.
Diff mount.
get the stiffer one while you're at it.

$150FC

at low rpms in first, if you can let off the gas and reapply and it makes the clunk, diff mount.

And have fun replacing that son of a bitch.

SureShot

Mine goes "tink" instead of "clunk". Does the Diff mount start to fail with a "tink" on startup, or am I loosing something else?
Bill

MrMAZ

just got a Mazdatrix 'uprated 'F.Diff. mount $99
but it it came in a O.E.M. bag with Mazda sticker on it .
sure it has no weight thingy on it , but how would I
know its uprated??
part no. FCY1-28-680 Mazda Automobile Genuine Parts
UNLESS Mazda are now making this 'uprated' part
cos they now the stock ones brake so often??
not easy for me to get on to Mazdatrix im in uk
Help someone please

Jimmy325i

The welded diff mount does make a bit of noise too, but just from the mount pulling the subframe around a little. I'd rather deal with a bit of noise than having to go back in there and spend 100 bucks everytime she lets go.

RoTaRyMaDnEss

the "clink" sound some1 mentioned earlier feels and sounds more like the heat shield for the catalytic converter

opelbits

iTrader: (5)

"Tink" is a sound made by a failing u-joint. Usually.
If you have a clunk, check the ends of the 'diagonal' links in the rear. I had one of them fail and it gave a prtty good 'clunk' sound. Made the back end feel 'squirrely', too.