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-   -   Transmission woes (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/transmission-woes-1091452/)

distr0 10-27-15 03:05 PM

Transmission woes
 
I'm on my 3rd (used) transmission now, and all have had the same or very similar issues, so before I go and replace it again, I'm trying to determine if the issue could be elsewhere. I believe all 3 transmissions have been S4 T2.

First issue is a horrible rattle noise at idle. Note that there's also a bad misfire, which could be contributing to the rattles.


Second issue sounds almost like a bearing 'screaming' or grinding, mostly when cruising in 4th gear, but sometimes in other gears as well (but not nearly as bad)


Could it be anything besides transmission? Clutch related? Driveshaft? Pilot bearing? Throwout bearing? Anything? Or do I just have really bad luck with used transmissions?!? :banghead:

RotaryEvolution 10-27-15 04:55 PM

assuming no cat on the car? how bad are the transmission mounts? how about the diff front mount condition?

could be simply your exhaust pressing on a heat shield, have you jacked up the car and tried to isolate where the noise is?

distr0 10-28-15 11:46 PM

there is a cat on the car... it may be hollowed out though, i'm not certain haha

the car was originally auto, and my auto-to-manual adapter mount is actually a bit 'off'. The shifter is a little low and a bit to the right. I'm wondering if that could be putting strain on something? U-joint in the driveshaft maybe?? It's very beefy though, and the rubber mounts themselves are aftermarket and pretty hard, so it's definitely not moving around at all. I'm going to try fab up a new adapter anyways though.

It definitely sounds like it's coming from the transmission, but i will get the car up in the air and try to reproduce the sound

misterstyx69 10-29-15 12:20 AM

there is a steel brace inside the cat that could rattle under acceleration if your cat is burnt out and nothing is holding that bracing intact.
Get the car up on stands or a jack and whack the cat with a hammer.

RotaryEvolution 10-29-15 08:52 AM

dead blow or rubber mallet not hammer unless you really want to destroy it, lol.

most likely it is your auto adapter or mounting though, i have never seen these issues typically with the turbo transmissions. they're virtually indestructable aside from 5th gear syncro and the main bearings whining when they get tired.

distr0 03-06-16 03:54 PM

1 Attachment(s)
just to update this, i ended up buying the Xcessive Manufacturing 'Auto Chassis to Manual S4 Trans - Conversion Cross Member'. The positioning of the transmission is much better now. Haven't been able to test yet but we will see if this fixes the death sounds

Attachment 752952

distr0 05-24-16 08:00 PM

finally got the car back together and driving. i installed the xcessive crossmember, replaced the hard poly mounts with stock rubber ones, and changed fluids... trans noises are MOSTLY gone. 4th still has some mechanical 'whiirrrr' and a bit of chattering but no horrible death squeals.

car has no no sound deadening or anything, so it's likely as good as it's going to get

unek87 05-25-16 10:04 AM

Man that's a nice mount bracket . Didn't know that was made . How much it set u back by chance

PinkRacer 05-25-16 10:21 AM

So remember my friend who had chatter in his transmission, only to put in another one and have the same sound? We're pretty sure it's the Bully clutch doing it after some reflection and chatting with the tech reps from Exedy - that may be the remainder of what you're hearing - clutch chatter. Could be due to the spring designs, etc.

distr0 05-25-16 12:35 PM


Originally Posted by unek87 (Post 12067772)
Man that's a nice mount bracket . Didn't know that was made . How much it set u back by chance

price was $125, it was exactly double that to my door, in canadian dollars


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