First of all, I have very little knowledge about clutches and transmissions outside the basic concepts of how they work, so pardon anything stupid I may say that's obviously wrong that I don't know.


Alright so, my 1988 GXL has a pretty bad clutch chatter issue, atleast from what I can tell. The issue is that whenever I am trying to get moving by smoothly releasing the clutch and giving it some gas, it feels like the rear end of the car shakes heavily and makes noises like it's shaking. It shifts perfectly fine after it is in gear including back down into first if I'm going very slow. The transmission has about 126000 miles on it, and the engine (a "new" 13b which was bought by the original owner and put in the car) has about 6000 miles on it. Something to consider is that no oil leaks out from the car at all, and something I find to be really strange is that in cold weather, this issue is not as severe, and almost goes away completely. I live in CenCal, which is very hot in the summer, which is when I got the car. In the mornings when the whole car is cool it feels much better and easier to drive but after it warms up it gets bad again. A month ago I drove to the coast for a few days and while I was there, the issue wasn't present at all, it drove wonderfully, although still a bit sensitive. On the drive home, the moment I crossed the mountains back into the central valley the clutch became ultra sensitive and would chatter a lot.


In 2018, when the new engine was put in, the original owner did some other work on the car, mounts, gaskets, etc, but most importantly he had a new "clutch set" installed (all this work was done by a shop for the owner, he did not do this himself). I couldn't tell you exactly what was all in the set but google results lead me to believe it was most likely a pressure plate, a release bearing and a drive disk. So unless those parts were faulty or put on incorrectly, I'd be under the assumption that they are not the source of the issue.


I have owned this car since June, and as it being only my second car I still don't know much in general. It's my first manual car that I drive, with a Miata being what I practiced with before I got the car. Since I bought the car, I just thought that was how sensitive the clutch was, due to my lack of experience with manuals up to that point. But since all my rotary buddies told me that they find their cars to be the easiest cars they've ever driven, it made me consider "hey, maybe I'm not just absolutely garbage at this, maybe it's the car".


My main question is, have anyone of you had to deal with this issue before, and how did you solve it? What was causing it? What would be the most likely culprit? And how should I go about getting it fixed (I don't want to break anything by screwing with it myself)?


That's about all the information I can think of that might be important but if there's anything else that might help have my questions answered I'll do my best to get it for you guys. Thanks!

 

Have you checked the rear end and driveshaft ujoints?

sounds like it could be a broken front differential mount. If so, it’s not a super easy fix but it can be done.

 

I haven't but I can check in a few days. If that is the issue what would I need to replace it, where would I get the parts and what would be the best way to go about doing it?

 

Rear differential mount is known to go break and cause the rear differential to rotate under load and the differential will tap the frame.

https://www.atkinsrotary.com/store/8...Y1-28-680.html

this or similar is a good idea. Stiffer rubber than stock. Check all rear subframe bushings while there.

Check: driveshaft ujoints, front differential mount, main camber link, lateral toe rods, individual camber links, rear steer bushings (which should get deleted if they’re still original and worn).

you said it was noise from rear end which should eliminate the possibility of clutch/transmission so take my recommendations based on that.

Link to all the rx7 manuals you’ll ever need which should help you.

http://foxed.ca/indexmobile.php?page=rx7manual

 

Check your mounts. . . .. Engine mounts, transmission mounts, and rear differential mounts.

The rear diff mounts are prone to go bad. . . .The other mounts just go bad after all these years.

I had this problem and that's what I discovered. . . .I lived with it for some time and then discovered the tranny and diff mounts were bad. When I fixed them, magically the stuttering went away, . . .Thankfully the mounts are still available and relatively cheap.

 

Alright so I bought a new flywheel and clutch kit and replaced it all. The clutch engages sooooo nice now. The original flywheel had been burnt which was causing the chatter. I got a mazdatrix light steel flywheel instead of resurfacing the original. Hope this thread helps people in the future.

 

Sorry to steal this thread!
I installed a new clutch last year and cannot remember if the instructions stated which side of the plate faces the flywheel?

Is there a standard orientation for clutch plates?

Someone on our forum did install his plate backward, so now I am not sure if I installed mine correctly.

I am ready to install the engine and transmission next month, so now is the time to check!

Thanks

 

It'll only fit correctly one way. The flat side of the disc faces the flywheel (front). The protruding hub side faces the transmission (rear). Here's a photo that shows the disc: https://www.ebay.com/itm/35542734780...njJiCc0k&gQT=2

 

Thanks for the information, now I will remove the pressure plate and see if it is installed correctly!

I'll take some pics and post them for people like me!

 

I removed the pressure plate and looked it over, seemed to be correct. I flipped the disc around to see how it fit, and no way it made contact with the flywheel!
So, yes the "flatter" face will always go against the flywheel! It will only seat correctly one way.
That's why the disc was not marked "this side towards flywheel".
Doing a clutch replacement for the first time as a DIY'er it is sometimes confusing.