Hoping someone can help me diagnose this issue. My 1985 GS has developed a very bad transmission shudder in first gear only. From a stop, when I put the car in gear and start to let the clutch pedal out and apply gas to get going the transmission shudders violently. The only thing that prevents this shudder is to give the engine a ton of revs, like 3-4000, and let the clutch pedal out relatively quickly. If I do that I still get a slight shudder but not bad. I also chirp the tires about half the time. If I don't do this, the shudder is so bad it shakes the entire car and I have to quickly put the clutch pedal back in for fear of breaking a mount. This happens right away and does not appear to be temperature dependent. I have been under the car frequently and can see no leaks of any kind. The slave cylinder appears dry and is not leaking.

Starting from a stop in second gear is fine. Just as you would expect from a second gear start, a little slow but smooth and no drama. All other gears are fine. First gear is fine as long as I am already rolling, even a little.

At first I thought I had developed some bad driving habit and I was not working the clutch correctly, but that is not the case, and the symptoms are getting worse.

The car has less than 40K miles on it, I use royal purple transmission fluid, and the shift action is excellent. The car is otherwise a gem, and runs perfectly.

Am I looking at a new clutch here, or worse? Flywheel hot spot maybe? But those would not explain second gear being just fine would they?

Any insight and advice is appreciated before I begin taking this car apart.

 

Where in Ohio are you located?

Usually clutch judder is caused by a clutch replacement without machining the flywheel. I would first check to make sure the engine and trans mounts are in good shape. I would ensure the mounts are also tight and that the trans mount is correct for the car and not something cobbled together by a previous owner. I've seen some weird stuff on these cars over the years.

 

I'm in Wooster OH. I think the car is on the original clutch, the miles are very low. I looked at the mounts and they look good, but I will check them more thoroughly and see how tight they are.

 

Exactly what mazdaverx713b says. Check all that stuff. I had shuddering on launch in first gear. Not quite as bad as what you describe but it was getting there, 35K on an 83 GSL, original clutch from the factory. I put in a new clutch (and if I can do it you can do it) and it's now a joy to drive. Buttery smooth.

Here's my thread from when I did my clutch, a couple of months ago https://www.rx7club.com/1st-generati...hread-1128545/

 

Wooster isn't terribly far away. If you need help let me know. I would bet that if the car has sat for quite some time there was simply rust buildup on the flywheel and clutch disc. The rust has been burned away and the surfaces are more than likely no longer in excellent shape. I would look at installing a new clutch disc, pressure plate, throwout bearing, and pilot bearing and seal. Definitely have the flywheel machined when you replace the clutch.

 

Thanks for the advice, and the offer to help. Looks like I am going to be getting ready to do my first clutch job. Winter is coming, so the timing isn't so bad.

 

Forgive me if I'm wrong, but won't the original clutch contain asbestos? If so you need to be very careful and wear PPE when you change it. Dispose of the old clutch VERY carefully. I'm not sure if an 85 model would have one, but I've heard SAs have them.
Just trying to look out for your safety

 

I guess its too late for me then! LOL!

 

No worries. I'm screwed, too.

 

Thanks for the advice everyone, and thanks for the heads up on the PPE, that is a good catch. I will use a mask and gloves, but for those already exposed it really shouldn't be dangerous unless you have heavy repeated exposures, so rest easy.