Just bought an '85 GSL. When driving it, if I step pretty hard on the gas, the motor takes off nice, but it feels like it takes a few extra seconds for the car to catch up and GO. I think it is a slipping clutch. If so, does it mean I need to replace the clutch and pressure plate or could it be something simpler? The car only has 53,000 original miles on it and has not been driven much at all over the past couple of years...

 

if u give it full throttle in gear and the rpms climb rapidly but the speed doesn't then yes the clutch is slipping.

 

Is a clutch replacement the only way to fix a slipping clutch, or could there be other causes? Only reason I ask is I come from the motorcycle world where something as simple as running the wrong oil could cause a clutch to slip... How difficult is it to replace the clutch in these cars?

 

Check the pedal free play you will find the specs in the FSM.s http://foxed.ca/foxed/index.php?page=rx7manual if the free play is good then it is very likely you need to do some clutch work .. After setting for a long period of time it is possible that here could be oil etc. on the clutch disc causing the slipping .. changing the clutch is much the same as any . just refer to the factory service manual for info .. good luck

 

Could be air in the system... maybe try bleeding the slave/release cylinder first. You could even go as far as replacing the master and slave cylinder for under $100. If that doesn't do it then its time for a new clutch and pressure plate with the release/throw out bearing.

I did mine just two weekends ago... not that hard of a job, just time consuming. I'm not a mechanic either, I work on computers but still like to take things apart.

If you do it yourself my suggestion is make sure you have four of the big jack stands and a big floor jack (not one of those little dinky ones). Also maybe 4-5 1ft x 3ft x .5in plywood or something. I staked the plywood up to get my car higher off the ground, which I needed the big tall jackstands. If you don't have the vehicle high enough you can't get the transmission out from under the car to replace the release bearing. Not a big deal if you want to do it under the car (it's not that hard) but its just easier to do when its sitting on the floor not under the car. Plus its just easier to work on the car with it higher off the ground. Those small jack stands never get my car high enough off the ground so its hard to work under the car.

 

automotive manual trans clutches aren't swimming in oil like the bikes. u can try bleeding the system and checking the pedal free play. but chances r it needs a clutch replacement.

 

I'm not seeing air in the slave or lines causing a clutch to slip. The pressure plate is spring-loaded and should still be compressed against the disc and flywheel.
If the rear main is leaking and oil has soaked the clutch disc or PP that would cause the symtoms described, but usually there's a distinct smell/odor associated with it.
Either way it sounds like there's a clutch replacement in the OP's future.

 

Thanks for the replies. I really appreciate it. I also notice that the clutch doesnt start to engage until the pedal is almost completely released.

 

So I've ordered a new clutch kit from rx7.com. Is it easy to see if the rear main is leaking while replacing the clutch? Is that something that can/should be changed while it is all apart?

 

As soon as you pull the tranny you will know if it is leaking , Actually if it was leaking enough to screw the clutch there would be oil dripping under the car ,,there will be oil on everything .. I doubt that is the problem .. I would bet that the clutch is just wore out , Does the kit come with a throw out brg. if not you should replace it also weather it seems good or not.

 

Ok, that's good. I did order all of the bearings as well.