1983 RX-7 base model

Here's what I have:

Factory rebuilt 12A, full Racing Beat exhaust system and RB air cleaner. Sterling carb. Rats nest removed. Engine runs very smooth and idles great.

A few weeks ago my son drove it and when exiting the expressway he downshifted into 4th and said something smelled real bad. He had trouble shifting after that and the violent rear end shudder began.

Here's what I've done:

1. I re-bled the clutch slave (new clutch & pressure plate was only days old as was the clutch master and slave cylinder and braided flex hose, but there was still air in the line).

2. Today I installed a brand new tranny mount, and brand new driveshaft from Mazdatrix.

I was sure this would fix the shudder but as soon as I go into reverse or 1st the rear end shudders violently!

What's my next step? What other info do you need? I'm no mechanic so please tell me what else to search on or patiently walk me through this. I will try to follow your suggestions to the best of my ability.

Thanks,

DD

 

Let me add:

1. I put in fresh diff and tranny oil.

2. There is NO "clunk" when going in gear.

3. No lightened flywheel.

4. This is not a "chatter" or "grinding". It's a shudder as if someone lifted up the back end of the car and quickly shook it from side to side.

Within the next few days (it's raining now) I'll jack up the rear end and see if anything is visibly shuddering.

Thanks,

DD

 

What did the tranny/diff oil look like when you changed it?

 

The tranny and diff oils both looked pretty good, actually. No burnt smell. No bits of metal.

 

Check the drivers side motor mount. If it's bad, the tranny mount may not last very long.

 

Clutch is toast.

 

nope i had the same prob.
U-JOINTS....

 

I think he already eliminated that........

When you replaced the clutch, did you have the flywheel resurfaced? If it is shuddering only when you are trying to take off, it could be the flywheel needing resurfaced. If you had it done, may not have been done correctly.

 

Thanks for the suggestions.

When we replaced the clutch (which was just before my son took that drive) I did NOT remove or have the flywheel resurfaced.

Guess I'll drop the tranny again, remove and inspect the "new" clutch disc and pressure plate, and try to remove the flywheel to get it resurfaced. I understand that's often pretty difficult (removing the flywheel, I mean). And if the clutch disc or pressure plate is bad, will the damage be obvious? What do I look for specifically?

If we have eliminated all other logical possibilities, hopefully we're pinpointing the problem(s).

Thanks,

DD

 

diff itself?

 

Fresh clutch needs a breakin period, usually 4-500 miles of stop and go driving before hitting it hard. Resurfacing the flywheel aides in the breakin. If the flywheel had hot spots/galling on it, a fresh disc has little hope, with a young driver, even less.

Btw, tell your son to remember that smell when you show him the bill for the parts/labor.

 

Loose pressure plate Bolts is my guess.

 

If this started suddenly when downshifting into 4th gear, I don't see how it could be clutch related (unless something came loose in there). Check your lugnuts lately?

 

You know that does sound a lot like a problem I had with my neon (my DD). I had changed from winter tires to summer tires and neglected to tighten the lugs on one of my tires. They were on and screwed in, but not tight.

At low speed the shake was wicked, accelerating the shake lessened and eventually stopped, but downshifting it would come back big time.

So double check your lugs man, they may not be tightened all the way. It freaked me out when I found mine, cause the bolts were hot and the nuts had been slowly backing out. That'll teach ya to double check your tires before you go driving, hehe.

 

Yep, once again, thanks for the responses.

The clutch pressure plate bolts were tight and the wheel lugs are tight. But I understand that they are good things to check first for this problem so thanks for the input.

When I say low speed I'm talking about only moving the car about 20 feet in reverse and then again 20 feet forward in 1st. It's not a "wobble" but a serious shudder or chatter when just beginning to move at this very low speed. I'll drop the tranny and remove the new clutch and get the flywheel resurfaced. The more I read, the more it sounds like that could be the problem as some have suggested. I don't have an impact gun so I already ordered the flywheel nut wrench and flywheel stopper. I'll let you know what happens. I also watched the video on Mazdatrix.

As the flywheel is getting resurfaced, how can I determine if the new clutch disc and pressure plate were damaged? If I see no "obvious" damage (broken glazed, cracked, damaged springs) can they just be reused or must they be replaced too?

Thanks,

DD

 

the new clutch is prolly fine.

good idea to go over the flywheel with an emory cloth during clutch service.

 

If the disc doesn't have serious burn marks on it, you may be able to scuff it up with 120 grit sandpaper. Keep in mind the you should be wearing a respirator when doing this.

 

Trochoid (alias Karnac the Magnificent) simply said "Clutch is toast."

Ya think??? Good call T-man.

What amazes me is my son got the car home like this. About a 20 mile drive after it shattered.




DD

 

damn!
yo clutch got knocked tha **** out!

 

whoa.. your son's shifting was 'too mad quick' for that disc...

 

2 words. Defective parts........................

 

I have never in my life seen a clutch that bad.

 

Not a clutch, but this is a pp I replaced in a friends turbo VW last summer. Took him to the 1/8th mile track for his first time. For some reason he had trouble launching. lol. Where the clutch mounts in the VW, had it come apart, he would be looking for new male parts if it gave way and went through the tranny case and firewall.

The give away in your first post was the smell, nothing else has that odor. I had forgotten what the smell was like until Dave roasted his. I haven't burnt up a clutch for 30 years.

I second the defective part with the friction material breaking at the rivets and little apparent wear. How does the flywheel and pp look?

It's satisfying to be right somedays. Just a blatant ego stroke.

 

My friend grenaded the clutch in his REPU. All of the friction material seperated from the rivets. Here's the mess I got to sweep up.

 

how in the world could he have done that. thats amazing. What brand of clutch did you purchase? I hope you can get a replacement.....