Gear grinds when shifting into 1st or reverse (1 Viewer)

[JOawaiian]

I have a four speed 1980 FJ40. When I first got my FJ there was no gear problems, but after a few months, my gears were starting to grind when shifting into first and/or reverse. Then over a few weeks, it increasingly got harder to get into 1st or reverse (never had any problems shifting into 2nd or 3rd), to the point where I would have to shut the engine off in order to get into 1st/reverse. Then one day, the plunger from the slave cylinder popped out, so I replaced both the Master and Slave cylinder.

With the new M&S, I am still having the same problem of grinding when shifting into 1st/reverse (and no problems when shifting into 2nd or 3rd). I noticed that sometimes, when I hold the clutch down for 5-10 seconds, it shifts into gear easier, with little to no grinding. I tried bleeding the clutch again, but still same problem.

Bleeding the clutch doesn't seem to be a complicated task, but can I be doing something wrong? Or is the push rod not quite long enough to fully engage (I have it extended to it's max length)?

 

[1911]

If there was air in the hydraulic system, the pedal would feel soft or spongy. If the pedal feels firm after you feel the clutch engage, it probably doesn't need bleeding again.

You should adjust the clevis pin that is between the clutch pedal and the master cylinder. The specs and procedure are in the factory service manual, but basically you want to take most but not quite all of the slack out. There can't be any pressure on the master cylinder when the pedal is all the way up, but you want just a hair of slack and a small amount of pedal movement before the master cylinder is engaged when you push the pedal.

Reverse gear is not synchronized in a four-speed transmission, so it will frequently grind if you shift into reverse directly from neutral. The answer to this is to shift from neutral into second or first, then immediately into reverse. If all else is well, this will solve your reverse grinding. Do this until it becomes a habit and second nature.

First gear is synchronized and should not grind. It's possible that the synchronizer for that gear may going bad, but that is a rare occurrence in my experience. Adjust your clutch pedal clevis and report back if that made an improvement.

 

[JOawaiian]

If there was air in the hydraulic system, the pedal would feel soft or spongy. If the pedal feels firm after you feel the clutch engage, it probably doesn't need bleeding again.

You should adjust the clevis pin that is between the clutch pedal and the master cylinder. The specs and procedure are in the factory service manual, but basically you want to take most but not quite all of the slack out. There can't be any pressure on the master cylinder when the pedal is all the way up, but you want just a hair of slack and a small amount of pedal movement before the master cylinder is engaged when you push the pedal.

Reverse gear is not synchronized in a four-speed transmission, so it will frequently grind if you shift into reverse directly from neutral. The answer to this is to shift from neutral into second or first, then immediately into reverse. If all else is well, this will solve your reverse grinding. Do this until it becomes a habit and second nature.

First gear is synchronized and should not grind. It's possible that the synchronizer for that gear may going bad, but that is a rare occurrence in my experience. Adjust your clutch pedal clevis and report back if that made an improvement.

If there was air in the hydraulic system, the pedal would feel soft or spongy. If the pedal feels firm after you feel the clutch engage, it probably doesn't need bleeding again.

You should adjust the clevis pin that is between the clutch pedal and the master cylinder. The specs and procedure are in the factory service manual, but basically you want to take most but not quite all of the slack out. There can't be any pressure on the master cylinder when the pedal is all the way up, but you want just a hair of slack and a small amount of pedal movement before the master cylinder is engaged when you push the pedal.

Reverse gear is not synchronized in a four-speed transmission, so it will frequently grind if you shift into reverse directly from neutral. The answer to this is to shift from neutral into second or first, then immediately into reverse. If all else is well, this will solve your reverse grinding. Do this until it becomes a habit and second nature.

First gear is synchronized and should not grind. It's possible that the synchronizer for that gear may going bad, but that is a rare occurrence in my experience. Adjust your clutch pedal clevis and report back if that made an improvement.

1911,
Thanks for the response.

I couldn't find the specs, but i followed your instructions with the slack and feel of the clutch. I ended up extending the clevis pin as far as possible, and I also extended the slave cylinder rod all the way. it seem to help a little, but overall, it still grinds when going into first. Reverse doesn't grind as much any more, and never, when i shift from neutral to second, then immediately into reverse - Thanks for that!

Any more ideas on what the problem is when shifting into first? Also I did notice that my transmission leaks a little now.

 

[whitey45]

Bad pilot bearing can cause this, input shaft still spins in neutral causing the grinding. Clutch disc not fully disengaged( presure plate issue, or bad synchro..

 

[thebigredrocker]

Here's a thread with clutch adjustment info

Help with clutch pedal adjustment

I replaced the clutch master and slave cylinder on my FJ55 and afterwards the clutch releases really late. Is it normal for the clutch to release at the top as I let off the pedal, or should it be releasing closer to the floor?

forum.ih8mud.com

 

[thebigredrocker]

Have you tried to pump the clutch pedal a few times before shifting?

 

[JOawaiian]

Bad pilot bearing can cause this, input shaft still spins in neutral causing the grinding. Clutch disc not fully disengaged( presure plate issue, or bad synchro..

That sounds like the problem, because the shaft is still spinning in neutral and it feels like I just need a few more millimeters to fully disengage the clutch.
I’ll replace the pilot bearing. Thanks.
Do you think that’s what’s also causing the slight leaking of the transmission as well?

 

[whitey45]

Recommend resealing the trans while apart and do the engine rear main seal while your in there.

 

[JOawaiian]

Thanks All!
I'll fill you in when completed.

 

[JOawaiian]

Have you tried to pump the clutch pedal a few times before shifting?

Yes. I tried pumping the clutch. But, what kind of worked is when i held the clutch down for 4-6 seconds. the grinding wasn't as bad, but i think it was mostly because the shaft was just slowing down from rotating.

 

[JOawaiian]

1911,
Thanks for the response.

I couldn't find the specs, but i followed your instructions with the slack and feel of the clutch. I ended up extending the clevis pin as far as possible, and I also extended the slave cylinder rod all the way. it seem to help a little, but overall, it still grinds when going into first. Reverse doesn't grind as much any more, and never, when i shift from neutral to second, then immediately into reverse - Thanks for that!

Any more ideas on what the problem is when shifting into first? Also I did notice that my transmission leaks a little now.

Lately, I’ve been shifting from neural to 2nd gear, and then immediately into first - and it’s been working with no grinding!
Ultimately, I do want to fix the problem, so I guess I’m going to have to get into the transmission. Just FYSA

 

[Runnin On Empty]

That sounds like the problem, because the shaft is still spinning in neutral and it feels like I just need a few more millimeters to fully disengage the clutch.
I’ll replace the pilot bearing. Thanks.
Do you think that’s what’s also causing the slight leaking of the transmission as well?

Pilot bearing issue shouldn’t cause leakage. But as stated above, reseal everything while you’re in there. May as well hit that rear main seal too.

 

[1911]

Lately, I’ve been shifting from neural to 2nd gear, and then immediately into first - and it’s been working with no grinding!
Ultimately, I do want to fix the problem, so I guess I’m going to have to get into the transmission. Just FYSA

That does sound like a bad synchronizer on 1st gear. At least you have a work-around, and it's drive-able until you feel like tearing down the trans.