Clutch or Transmission Going Out???
 

Ok, got a 84 GSL-SE that I've had since Dec 2016. About a month ago, started developing sounds in Transmission, which I thought was the throwout bearing, as only made the chattering sound when clutch was fully depressed.

The car sat for a few weeks as I redone the brakes, suspension and put a RB exhaust on it. I finished all that up last weekend, and the clutch noise had disappeared. I put about 20 miles or so on it, and never heard the chatter.

Last night, getting ready for DGRR, I changed all the fluids (motor, trans, and diff). I used RedLine MT 90 for the transmission, and put the required 1.8 quarts in. Checked for leaks, and none present.

Today, I took her to Frankfort - about a 330 mile round-trip drive. Drove great the first 331 miles, and then became hard to shift into 4th, then 5 miles later, unable to shift into any gear. I pull off side of road, kill the engine, and look for transmission leaks, which I don't see. Start it back up about 3 minutes later, and shifts fine. 15 miles down the road, hard to shift again. I have a good clutch petal, and I hear no sounds from transmission. Sometimes I can force to get in a gear, but I hear the grinding.

Is my clutch going out, or the transmission?

Let me add, that once I got her home, I pulled it on the rack, and transmission is full of fluid - no leaks at all

Possible T/O bearing,pressure plate,clutch disc hanging up on input shaft splines. How does clutch feel when engaging and moving off in 1st gear?
Where in clutch pedal travel does clutch begin to engage,near the floor,near the top,consistent each time? Any play in clutch pedal when first pushed ? Clutch master cylinder full,have you tried bleeding it. Have someone push clutch pedal to floor while you watch slave cylinder/release fork for movement. When car acted up,while shut off,did you try to shift between gears(all)? There is a small amount of oil that needs to be in shifter turret to help all pieces move smoothly. Worked on a GSL some years ago had symptoms similar to yours,adding oil there alleviated the problem. Sure sounds like clutch release?hydraulics issue to me.

Sent you a pm.

Your Pilot Bearing has grenaded.

Here's what's happening; the pilot bearing sits in the middle of the Eccentric Shaft and is the 'pilot' for the transmission input shaft. The Pilot Bearing has a Rubber Seal that helps to keep the grease in place, and when the Pilot Bearing or Seal gets old or dries out, the needles in the center of the bearing get hot and shatter. The mild grinding you heard when the clutch was depressed was the Pilot Bearing getting ready to fail. Thereafter, when it stopped making the noise - the bearing had seized. Even later than that, when you weren't able to shift - it's because the Pilot Bearing had shattered into dust and that dust was enough to jam what was left of the Pilot Bearing into the Input Shaft of your transmission, thereby spinning the transmission even though your clutch was depressed.

In effect, when the Pilot Bearing failed, it caused the input shaft of your transmission to be semi-mated to the Eccentric Shaft of the engine. That's why when you shut the car off, put it in gear (blocking the trans from spinning) and restarted the engine, it behaved normally. Once it got hot again (15 mi later...), the chunks of Pilot Bearing expanded and acted to mate the trans to the engine again.

The Pilot Bearing is at maximum 'use' when you have the engine spinning at high speed and the clutch pedal down. It's in this condition that the Pilot Bearing is forced to rotate at maximum speed differential. The least 'use' is when the trans is in neutral and you let the clutch out - as in this condition, your clutch disk is mating the engine speed to trans speed, and the Pilot Bearing isn't even spinning. Hence, you only hear the Pilot Bearing getting ready to fail when you the engine is turning, the trans is not, and the clutch is depressed.

Pilot Bearing replacement requires pulling the trans. It also requires a Pilot Bearing Removal Tool from Mazdatrix if you want to save yourself a few hours of screwing around with trying all the various methods of removing a Pilot Bearing race that has welded itself to the inside of your eccentric shaft... Or, the low-cash (aka 'ghetto') alternative is to pull the trans back far enough to reach the end of the Eccentric Shaft and thoroughly clean out all the slag and broken pieces of Pilot Bearing and then put the trans back in place. This removes the Pilot Bearing from the equation, but you also risk Clutch chatter and vibration, because the trans input shaft is no longer supported at it's nose.

Long term - best fix; pull the trans, get the tool, replace the Pilot Bearing and Rubber Seal (and regrease it!), install a fresh clutch disk, throw-out bearing, and take a close look at your Trans Front Cover to see if it's worn at all. This is the time to replace anything in there that looks 'iffy'. Penny-wise is pound-foolish.

Post back if questions,

Thanks -- the pilot bearing disintegrating makes sense. I'm gonna put her on the rack next weekend. I've gotten enough info from these posts to know what to do, and what I'll need. Advance has a "universal" pilot bearing removal tool for rent. I've sourced my socket and impact wrench.


I would have posted a few days ago, but I keep getting "Bad Request" when trying to access this site using my regular Chrome browser. Had to jump over to IE.

Had same issue with mine, thought it was T/O bearing had gone out. Turned out to be pilot bearing failure, and it had seized on the shaft. Luckily had a spare trans. Replaced clutch slave cylinder, T/O bearing, pilot bearing... clutch and flywheel did not need to be replaced. PO owner had it replaced before I purchased. Unluckily the guy I had swap things out most likely did not get the rear main seal completely seated, have some drips from trans now. And now it is making noise again like T/O. So waiting for it to break and then have someone else replace the same items.

Hope you got it sorted before DGRR.

Didn't make DGRR - bearing shit on me day before I was gonna leave. That may have been a blessing in disguise, but I wish it would have waited at least another week.


I've not tore the trans apart yet - gonna do that next weekend. I spent about 15 hours mated up with a push mower this past weekend.


I hope like hell my transmission isn't hurt. I'm getting the pilot bearing tool from Advance

Get the tool from advance, round off the corners (when you see it and the pilot hole you
will know what I mean) and then use it to pull the bearing. Keep or return. I kept mine for next time.

You want to replace as many things as you can when this is out: pilot bearing, TO bearing,
front tranny seal, rear seal, ujoints on driveshaft, tranny mount, and tranny gaskets where the
stick goes into the tunnel. Might look at the starter if its been giving you issues as well but be
warned, reman rx7 starters are a crap shoot. Might want to do the slave clutch cylinder and
line as well while its out.

I've got an Excedy kit that has the TO & pilot bearings. I've got a new trans mount, and my starter has been replaced recently, so I'm good there. I've also got a new slave from RockAuto that I plan on using.


On the driveshaft, I didn't think the u-joints were replaceable? I see RockAuto sometimes has the new shaft for under $300, but I'm not having any issues with mine at the moment.


I'm getting the gaskets from dealership

Get pilot bearing grease seal,rear main seal for engine(Mazda oe). Replace both clutch master & slave cylinders'look at hydraulic hose going from master to slave closely,as long as i'm spending your money...go ahead and replace too. +1 on transmission input shaft seal/gaskets/tailshaft seal. Don't need to be OE. Examine driveshaft closely while out,work both ends full travel 90 degrees in all direction,feel for binding...before take shaft out,try to move up/down/sideways to feel for loose joints. Easier to feel play while still bolted in car. Car is 32 yrs. old,take that into account. If you're keeping it,want it to be reliable,and only want to do all this once ,be thorough.

Don't hit the flywheel with regular hammer to pop free of eccentric shaft,use brass/copper hammer to prevent damage. Have flywheel resurfaced while out,clutch engagement will be much smoother. Certain to have hot spots,uneven surface when you pull clutch off. Take the time to clean up bellhousing were starter mounts,and clean the power and ground cables at starter til shiny. Put a smear of vaseline on wires when done.
Guarantee you will hear the starter spinning the engine over faster when you start for first time,do this even if you think it's cranking fine as is. 30+ yrs of oxidation results in considerable voltage drop in starter circuit. +1 on reman starters,don't trust them. I rebuilt mine,works as new.

Here's what I got coming from MazdaTrix. I didn't see the gasket for the shifter




SEAL TRANS REAR
71-85 ALL AUTO + MAN
17-335A-0437
GASKET TRANS
FRONT COVER
16-2250-8540
CLUTCH SLAVE HOSE
81-85 STAINLESS
6508
CLUTCH PILOT SEAL
ALL ROTARY 74-ON
11-404A-1881
SEAL TRANS FRT INPUT
79-92 ALL INCL TURBO
16-1030-0603
CLUTCH SLAVE HOSE
84-85 HARD LINE
45-5100-FA66

One more thing,more is not better when greasing pilot bearing. You can put too much in and no matter how hard you try you cannot get trans in fully,hydraulic lock will prevent trans going in all the way. I learned this the hard way many,many years ago-benefit from my mistake. Consult fsm about lubricant in shifter turret. Oh,one more thing-resist temptation to draw the trans up to engine with mounting bolts,if everything lined up,trans will slide right in,maybe not without some finagling but will slide all the way in to engine. Trans mount very likely to be separated,replace that too.

Really wished I lived closer to one of you experienced people, but I've gotten enough great advise and information on here, that I should be able to do this job. I VERY much appreciate all the help and advise.


Kevin

If original shift turret gasket intact,a light film of rtv will reseal fine. You have my # call if you need 2 cents. Take pic of whatever and send so can see what you're having trouble with.

Thanks Mike

Why are we suggesting that he pull the flywheel? There's no need to do that to replace the Pilot Bearing and the Pilot Bearing Grease Seal - as it's staring you in the face after you drop the Transmission.

These are the 2 parts you definitely will be needing:
http://www.mazdatrix.com/pictures/g-...lotBearing.jpg
and
http://www.mazdatrix.com/pictures/g-.../PilotSeal.jpg
at: http://www.mazdatrix.com/f-other.htm

While you're there, this is another one of those Single-Job tools that comes in handy for the cheap price:
http://www.mazdatrix.com/pictures/to...otInstallS.JPG

For the limited torque available from our cars when stock, there's very little reason to resurface the flywheel unless you're getting chatter regardless of Clutch Disk and Pressure Plate replacement.

I'd focus on the parts listed in my post above, which many have echo'ed. Good luck,

"We",as i'm certain directed to me & no offense taken, recommend for two reasons. First to replace the main seal on eccentric shaft,itself for two reasons,its age and do you have any idea of how many clutch jobs are ruined by oil leaks afterwards and cause is rear main seal? This is not specifically about rotaries,they're no different in this regard.

Hit send prematurely..other reason is flywheel runout. Back when 1st gens were fairly new i did clutch jobs fairly frequently,say 200+ over 15yr period at Mazda dealership where i worked. Cleaned up a lot of flywheels,installed new Mazda clutch kit(there were two clutch discs available,one for more aggressive driving) and send on its way. A fair percentage of cars came back with shudder/judder complaints about engagement,bigger share from the aggressive clutch disc install. Some could be attributed to driving habits. The fix was to machine flywheel and became pretty much sop from that point on,was a judgement call for most cars and owners were given the option to machine or not.
This is akin to slapping new pads on old rotors that "looked" ok and being surprised at resultant pedal pulsation/noise/steering wheel vibration and resultant complaints There are times this doesn't happen,but being a professional,i don't gamble with the percentages. Would rather do the job once correctly and explain the cost to customer, than try to explain reason for vibration/judder to an unhappy customer on a "comeback". My own previous 1 owner SE flywheel had a surprising amount of runout and uneven surface so of course it was machined. I did experience occasional shudder on engagement,which was an annoyance. I'm persnickety about issues like this and a thorough clutch job gives butter smooth clutch engagement and will stay that way much longer,fits with my do it once,right first time philosophy.

Happened yet again,composed response reconfigured once reply button hit. This after complete response disappeared and had to be rewritten because on trying to reply,was prompted was not logged in which of course i was,and re-logging in causes complete disappearance of post. Pretty much bs,does not occur on other sites i frequent?

Sounds like cookies are timing out early. Maybe a system time issue?

+1000 on everything said above. The cost is minor compared to the time and effort when
the un surfaced flywheel shows its ugly behavior and Mr. Murphy will make sure that
happens.

I'd prefer the flywheel be removed and resurfaced, since I'm in the job already. I'm hoping an electric impact wrench will do the job.


I make sure to copy my reply before I hit the send button because this site times out way too fast, and I get distracted easily