Thread: Transmission grinding in gears.

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Well folks. I figured out (with everyones help) the no brainer vibration trouble. Bad u-joint. Now I've decided to tackle the transmission issue.

My transmission grinds slightly in between shifts. If I allow a slight pause between shifts it wont grind so I believe the synch's are still spinning?

91 Wrangler 2.5 ltr 5 speed.

I made sure the slave cylinder was bled with my son's help. No air in the lines. I literally have what I concider no pedal stiffness at all. Just the tension of the spring on the pedal. This thing has the slave cylinder thats built in to the throw-out bearing. Now that I've made sure there is no air in the lines I'm thinking either the slave cylinder is bad or the clutch master cylinder? When I have the cover off the clutch master cylinder....and my son actuates the clutch pedal.....shouldnt I be able to see the level drop slightly in the resevoir....and then see fluid flowing back in....like you'd see in a brake master cylinder? When I bled the lines....under pressure fluid would shoot out of the bleeder like it is suppose to. Maybe my pressure plate is bad? I'm thinking that this would keep the face of the clutch in slight contact with the flywheel....not allowing the transmission to be free from the engine...hence the syncro's still spinning causing the grinding?

I'm not experienced with the manual transmissions but I'm trying.

Any help appreciated.

Thanks,
David G

Originally Posted by DennyW

Ok, one of my first questions is this: When you have the vehicle in gear, and you ease out on the clutch, how far off the floor does it move until you feel it starting to engage, and move the vehicle ?

I believe at about a 1/3 of the way from floor the Jeep will start moving. I will make sure I take note in the morning on the way to work though. But fairly confident it is 1/3. This thing has an internal slave/throw out assembly so there really is no adjustment....correct? Picked up a 'new' not reman unit yesterday.

When I seperate the transmission there should be no side to side up and down play in the input shaft...correct?

I may take the transmission to a shop and have them give it a good look over. If folk are right and my sychro's are bad I have no business digging in there. If I took it apart....well lets just say it would be catostrophic. I now a guy thats a miracle man on transmissions. Heck....he has a contract with the military to rebuild tank transmissions.

BTW. Thanks for the help with the vibration Denny. Appreciated!

Thanks,
Dave G

Originally Posted by DennyW

Ok, the reason I asked where the vehicle starts to move is I wanted to make sure you were disengaging the clutch. Sounds like you are. Now, with the mileage you have, a new clutch is probably a good thing... But, I would say you will have to take the trans to the trans guy you know, and most likely, the blocking rings are worn out. Not to mention some normal wear, and end play. The blocking rings are the brass rings with a taper inside. When you push on the shift handle, this applies pressure to the blocking rings, and stops the main shaft from spinning, allowing you to go into gear without grinding. Once you get the trans there, I'm sure he will check out the shift forks also.

BTW, I used to do the tanks also. The 88's were my favorite ones...

ah o, site messing up ...

Thanks Denny. Ah the enevitable has come. Shucks....I've been babying her for 3 years now but now its time to make it driveable for my son. Do the internal slave cylinder/throw out bearings self destruct when seperating the transmission from the clutch?

For real Denny...Tanks? I took my RX8 transmission to this guy.....heard about him from some locals.....drive way out in the middle of 'nobody near'.....walk into his shop....and there sits two huge tanks in the middle of the shop. Now that was just cool. One was his....and the other was what he called....'A special project'. He said he was a tank engineer/mechanic for I belive he said the Marines. Real nice guy. LOL's. You could see tank tracks all over his property.

Thanks,
Dave G

How does it act when you put it in gear..especially reverse or first, does it grind then?? If it does try putting it in 4th,then quickly to first.. If it inproves it the clutch is not disengageing properly..

Originally Posted by Daffy427

How does it act when you put it in gear..especially reverse or first, does it grind then?? If it does try putting it in 4th,then quickly to first.. If it inproves it the clutch is not disengageing properly..

No it doesnt grind when putting it in gear....reverse or 1rst. Only when upshifting without and extended pause.....or down shifting no matter what I do. I pass off someone stopping and turning in front of me....to bad luck. If they stop completely its no big deal....but if I'm still rolling any I have to place firmly in gear to keep it from grinding too much.

Thanks,
Dave