87 Bronco II with FM145 Difficulty Shifting Into Gear

[Segagee]

Hello all, new member from South Carolina here. Just purchased a 1987 Bronco II with the Mitsubishi FM145 manual trans on the cheap a few weeks ago. The truck initially had no clutch pedal (all the way to floor), but replacing the slave cylinder fixed this problem. Clutch pedal is fine now and the clutch seems to be disengaging properly when taking off. The problem is, however, I have difficulty shifting the truck into ANY gear while moving and have to pump the clutch in order to shift, and it is still very difficult to do so. The trans had fluid in it (90w gear oil), but I flushed it and replaced, which seemed to help the rough shifting only very slightly. I have also tried bleeding the system/clutch master cylinder from behind the pedal as well as the bleeder valve on the tranny. Neither has helped, and I am assuming the system is bled properly because there is no sponginess in the clutch pedal.

I have yet to replace the clutch master cylinder, but given I have a solid clutch pedal I'm not sure how to test if it "bad" or on it's way out or not. It is not leaking. Is it possible master cylinder could cause the difficult shifting? Just looking for some basic info before I have to tear into the tranny itself. I would be kind of surprised if the tranny itself was bad or all of the gear syncrhos went out at the same time. Not really sure how durable these FM145's are.

Thanks in advance for any help/advice.

 

[3rd Petal]

Can you shift it through the gears fine when it is stopped or when the engine is off?

Also, these transmissions are supposed to have ATF in them. I don't think it really matters though

 

[Segagee]

I can shift through the gears when the engine is stopped/off, but it is still a little stiff.

As for the ATF, I initially thought the 90w oil that came out of the tranny when I drained it was not a good sign until I found the link below.

I replaced the 90w with 10-40 when I refilled it, didn't know if I should put ATF in it instead or if it would make a difference.

http://www.therangerstation.com/tech_library/ManualTransmission.shtml

 

[ab_slack]

Are you saying you put 10-40 engine oil in the FM-145?

First clarification on what goes in the trans.

The FM-145 uses gear oil 80-90 as stated on the link you have. I have not heard of putting ATF in the FM-145.

It is the M5OD that uses ATF.

How do you know it is not spongy? It isn't like with brakes where you are pressing against a hard surface so feels very firm. The clutch you are pushing against the return spring so it always has a spongy feel in my opinion.

Getting all of the air out of the slave cylinder is a real pain. You can find info on TRS on how to do that. As I recall dismounting it and turning it over is a method used but don't quote me on it.

Back to basics though.

Scenario, you are stopped, have vehicle in neutral and start it. When you depress the clutch, while sitting still are you able to move the shifter into every gear position? Just some or none?

Cause if you can't do that, I certainly would start thinking the clutch isn't disengaging although the pilot bearing could be messed up and causing some drag even with clutch disengaged.

If you are able to do that, that tends to eliminate the clutch itself. There could be badly worn synchro. I don't know if you are aware of how to shift without using clutch relying on the feel of the syncho to let it drop into gear, but if you do, the question is if that is possible. That would tend to validate the synchro.


To check the pilot bearing, with it in neutral and clutch you should hear some general rotating noise from trans. It isn't very loud but there is some. If you push in the clutch, how long does it take for the noise from the trans stop? If you have some drag it can be a few seconds. If it good it should stop quickly. My 87 takes about 4 or 5 seconds, it has some extra drag on it. It causes a shifting problem with second gear when cold and getting into reverse when stopped unless I give it those few seconds between shifting.