1991 Manual Tranny

[Triton46]

Not sure what is going on at this point, but it is getting worse. Towed my jetski to the lake today, on the way home I went to downshift from overdrive to fourth and got a grind. Tried again and it grinded into fourth. The rest of the way home was uneventful.

I changed the tranny fluid about 8,000 miles ago when 2nd was grinding a good bit. What is going on here?

I was thinking of having the clutch checked out/replaced but if I do that I might as well go ahead and have the tranny overhauled while its out...right?

How much would it cost to have the clutch, master slave, and tranny replaced with rebuilt? (parts/labor)

 

[Clint]

when u changed your oil in your tranny did u do it or did u take it to a shop ..... what kind of oil did u use? .....

 

[Triton46]

I don't think its the fluid...

I changed it using Mercon ATF just like the manual and Haynes recommended.

This smoothed out the 2nd grind for a few months...it still does it but not as regularly as before.

 

[J_Moran82]

Try bleeding the clutch it worked for me when I had a similar problem.

 

[jimbo74]

i am not sure if you have it or not but it sounds like your syncros are going out......

 

[Triton46]

bleeding clutch...

J_Moran

I considered this...how would I go about this? Is it as easy as bleeding the brakes?

jimabena,

Yes, I beleive the gears are 'synchro gears' in the mazda transmission.

 

[J_Moran82]

its easier the bleed valve is on the driver side of the tranny. you can follow the hydraulic line from your clutch master cylinder which will be a plastic cup looking thing mounted to your firewall behind the brake master cylinder. Take the cap off and pull the black rubber piece out and fill the cylinder with dot brake fluid. then bleed from the bleed valve just like you would the brakes, untill there are no air bubbles, but make sure that there is plenty of fluid in the master cylinder. After you are done fill the master cylinder to the ridge (about half way) and put the black membrane back in. Read your hanes manual just in case I missed anything. I hope this helps.

 

[Triton46]

Does the clutch use DOT3 brake fluid? I can't find the specs in my Haynes manual.

 

[J_Moran82]

yeah it uses the same as the brakes

 

[JDraper]

Tranny rebuild or replace=EXPENSIVE!! I had the 5 speed rebuilt in my old '92 when the input shaft bearing gave up the ghost and took some other stuff with it. Gears were ok though. Cost 1500 for the rebuild, and 200 to have a new clutch/pressure plate/throwout bearing put in while they had it apart.

For the grinding, it could either be synchros, or the clutch not releasing properly. An easy test for the clutch not releasing is when you are sitting still. If you are at idle in neutral, push the clutch in, wait about 2 seconds, and drop it into reverse. If it doesn't crunch your clutch is releasing ok, and it's probably synchro related. If it grinds after a 2 second wait, you're clutch isn't releasing properly. That could be caused by air in the hydraulics. I'd try a bleed at that point.

 

[Triton46]

JDraper,

Looking back...I wish I had bought that from you.

When you say 'crunch', what do you mean? It has never 'grinded' into reverse, but it has always been difficult on all gears since it was new. When I say difficult, I can only compare to a car or Jeep manual which slides in and out of gear easily. Mine always pops out easy, but going in you can feel the sychros. My girlfriend's Dad test drove the day we left your house and he said all felt good.

I am going to try bleeding the fluid, but what is there any sign of when to replace the clutch?

 

[JDraper]

Usually, the first thing you notice when a clutch starts to go is that it slips when you are under hard acceleration. The rpm's will come up, but you won't be accelerating. Having said that, if you need to get your tranny serviced, and you are still on the original '91 clutch, get it done at that time. It's worth the couple of extra bucks for the parts since everything is already apart. That's what I did when my tranny died. The clutch was feeling fine, but at 90k+ on the clock, I didn't want to take the chance of having the tranny done, and then 5k later having it removed again to put a new clutch in. Better safe than sorry.

As for the 'crunch', I mean it will grind before it goes into gear. If it doesn't grind when you do the test I mentioned above, your clutch is releasing ok

 

[Triton46]

I'm having some problems. I removed the bleeder screw but left the bleeder valve attached. I can hear fluid running and the reservoir goes down...but the fluid never runs anywhere.

I have a pan on the floor, I let the reservoir go half empty, then closed the screw. Still no fluid in the pan...

Where is the fluid going?

 

[J_Moran82]

You dont remove the bleeder screw. There is a hole in it for fluid to come out of. You have someone in the car to pump the clutch pedal then hold it to the floor. At which point you losen the bleeder screw just enough so fluid runs through the clear tube. There will be some air bubbles in the fluid that comes out. you then close the bleeder screw and have the person pump the clutch and hold it to the floor again. You repeat the process until there are no more air bubbles.

 

[Triton46]

I did not remove the bleeder screw. I unscrewed until I could hear fluid but none was coming from the screw.

 

[Triton46]

Update:

OK, I had a friend pump the clutch 8 times (holding it down on the eighth time).

Underneathe the car, I opened the bleeder screw. Brake fluid shot out then stopped. I closed the bleeder screw and had my friend let off the pedal. As he did, the fluid in the reservoir began to sink. We did this about 5 times, refilling the reservoir on the 2nd time.

Is this correct? Will this flush out the whole system?

 

[J_Moran82]

you need to have a clear tube or something to make sure you got all the air bubbles out.