Clutch or Synchro Issue
 

How do I differentiate between the two?

Before I had trouble getting into Reverse gear. So based on several recommendations I had the dealer put in MT90 in the Tranny and Redline Gear oil in the Differential. (Hopefully he didn't get the bottles mixed up)

For now I haven't had trouble going into reverse after the fluid change.

Now when I am revving fairly high the car grinds a little going into 4th.

The dealer did say the clutch is on it's way out and needs to be changed.

If you are getting gear grinding while shifting, then either your clutch isn't completely disengaging or your syncros are going. The only clutch disc failure that will cause a grinding of the gears is a burst clutch, which usually produces other very noticeable problems that you didn't mention.

Do a pair of tests:

1) find a perfectly level slab of pavement somewhere. Pull onto it and come to a complete stop, clutch in, 1st gear, and foot on the brake. Now let off the brake. If your car start to pull forward AT ALL then your clutch is engaging slightly, and you either have a bursting clutch, failing clutch hydraulics, or a clutch pedal that isn't adjusted correctly.

2) Double clutch when you shift. If the grinding disappears, then it's the syncros.

A simply worn clutch is when the clutch slips when you don't have your foot on the pedal, usually most visible in 2nd gear around 5,000rpm, the rpms will start climbing faster than the vehicle speed, and/or the vehicle speed will be increasing with the rpms steady (as the vehicle comes up to speed to match the correct rpm for that gear)

4th gear has a few problems associated with it on this gearbox. If the issue only occurs during 4th gear shifts I wouldn't expect it to be due to a wore out clutch.

Thank you I will do those tests.

Another thing I began noticing is at high RPMS I find gaps in the power band. It's kind of difficult to explain.

It's like the car is climbing in speed then all of a sudden for a very short I can fee the engine is in a free spin and then it's back again. Sounds like a bad clutch huh?

Car has 60K miles and this is my first manual :D

also check the clutch pedal bracket for cracking, it may be fatigued which is dragging the clutch. it is a common issue but usually not a moderate one like this, but it is a possibility.

if the engine ever revs up and speeds are not climbing to match RPMs then the clutch is slipping. it could be a possibility that the pedal was adjusted to compensate for a broken clutch bracket and causing the slipping in an attempt to cure the grinding. this could still allow for a dragging clutch when depressed as well as a slipping clutch under heavy loads, because a broken bracket will greatly reduce the clutch throw.

if the car ever wants to lurch forward when going into first from a complete stop then the clutch is dragging, as mentioned. it should go in very easily and not feel like it is trying to push the car at the same time.

a search will come up with what a broken bracket looks like and what to look for. the inspection can be done by anyone with a flashlight under the dash.

Well I did take my car in when the Clutch bulletin was put out. The dealer adjusted the clutch but now I noticed there is dent on the floor board where the clutch has a left an imprint.

Also I did the stand still test mentioned by RIWWP with the clutch in and gear in 1st with no brake and the car didn't move.

On other news ever since I did the test as mentioned by RIWWP with the double clutch the car seems to be behaving very well. I doubled clutched on high rpms all the way yesterday and this morning the car was just normal. I still didn't get a chance to shift to 4th from high rpms but the clutch just felt better. No squeaks, no resistance while to depressing it. Just felt faboulous.

I am going to however replace the clutch pedal for now and will hold off on the clutch replacement.

BTW what's the labor charge typically for a clutch replacement? Dealer said $599 just for labor. Sounds OK to me.

That labor price is about right. You don't want to buy the clutch from a dealer though. Dealer charges for every part of the clutch system separately, and depends on markup, but usually lands in the $800 range. Vs, you can buy everything you need in a clutch kit from BHR for $375 shipped. You don't need a dealer for the clutch replacement, it's pretty simple and any reputable shop can handle it fine.

Yeah the plan was to buy it from Mazmart who is local to me. Any difference between the Factor clutch and the Exedy Stage 1 ? BHR has the Stage 1 for a bit cheaper?

Also is it reccommeded to change the flywheel to a lighter one? Dealership told me big no no saying some blokes who had done it came back with issues.

Those people likely came back complaining that they couldn't drive their cars with the new lighter fly wheel. It really depending on just how much weight you want to lose, but it will change how it feels to drive and takes some getting use to (gains and loses rev's quicker making it easier to stall out since there is less rotating momentum).

IMO - if your planning on doing the clutch adding the fly wheel at the same time is a good idea. They already have the transmission and everything taken apart, so adding a new fly wheel to the install doesn't really add any more time that they can/should charge for.


Easiest way to test for clutch slipping is to cruise in 2nd gear in the higher end of the RPM range (5,000ish) at a constant speed and under as light throttle as possible. Then suddenly floor it. If the engine revs up but the speed does little to no changing, then your clutch is clearly slipping.

So more developments

Double clutching absolutely gets rid of the grind that I get when going into 4th. Anyone know y?

When the car is cold during early morning commute the clutch behaves the best, everything shifts smoothly no problem. But back home in the evening I have to double clutch else I get the grind.

This maybe unrelated but my car takes longer to start. It sounds like the engine isn't spinning and then all of a sudden just when you think it's not going to start, it comes to life. Best way to describe is the old bi-planes that needed to turn the propeller to start. Sounds exactly like that.

All lightweight flywheels for the 8 need a counterweight, I expect anyone with issues on the install missed that part.

Exedy Stage 1 is slightly cheaper in price, harder clutch pedal, a bit higher torque capacity, and very unreliable lately. Lots of Stage1 problems being reported by more than just me, and I had one fail in 20,000 miles of the same driving that got me 90,000 on the OEM, and I had it's replacement never right from the start, lots of noises, weird pedal engagement, and the clutch was shredding itself apart in only 100 miles. Other people have had similar problems, though it's not consistent exactly what problems people have, so it's suspected to be a quality control problem with that clutch at Exedy.

It totally isn't worth the $25 when you have to buy the OEM clutch anyway and pull the transmission a 2nd time.

Your syncros are failing, however the changing behavior over time may be due to fluid temp changing. How old is the fluid? Replacement interval is 30,000 miles, so you should be due for your 2nd, which may actually be your first. Fresh fluid may restore your syncro's ability to work.

Sounds like a really weak starter.

Actually I just changed the Fluid. This would be my 3rd time changing it. I first changed it Royal Purple. Didn't like it much and changed back to factory.

I recently changed it to MT90 like 2 weeks ago. Is it possible the dude who changed the fluid mistakenly put Diff fluid into the tranny by mistake? The dam bottles look alike. That's when the 4th gear grind made itself known.

So with the double clutching and the car behaving itself, you think it's NOT the clutch?

And if there are no issues when the car is cold, wouldn't that mean the fluid is the culprit?

Well, there you go, Royal Purple.

It destroys our syncros, usually within a few thousand miles. Start keeping an eye out for a replacement transmission.

Google search: site:Rx8club.com royal purple transmission synchro failure
https://www.google.com/search?q=site...&ved=0CCsQBSgA

Royal Purple is marketing-speak for: "we hooked another sucker ..."

Well I took the car to Mazcare and sure enough the dealership swapped MT90 and Gear Oil. Dam I am so pissed. Good news is I haven't driven it much since the change.

Now having Mazcare put in BG Synchroshift in the Tranny and Redline in the diff.

On other news I was told I would need new coils since the car is at 60K miles. Dam things are expensive. And since my Throwout bearing is on it's way out, I was recommend to get the clutch replaced as well. So shopping around for a shop that can replace it for a decent price, else I'll have to save up for Mazcare to do the work.