Diagnosing manual transmission problem

'92 explorer all stock with 5-speed manual. I recently did an engine swap in this truck and have it on the road now. I put about 200 miles on it so far. It is getting hard to shift it into gear from a dead stop. If I put it into third gear (while holding the clutch in, not moving), I can then get it to go into first gear. When it does this, I still have about the same let-out on the clutch pedal before it engages the clutch so that seems normal. I was thinking pilot bearing, but I can shift it into third or fourth no problem.

In the process of the engine swap, I put a lot of new parts in since I had it apart. I put in a new clutch, new slave cylinder (oem ford part), had the flywheel resurfaced and a new pilot bearing. In the tranny, I put in a new shifter bushing. I also put in a new 5th gear and new bearings on the output shaft and rear of the countershaft. I looked at the syncronizers and they looked good (for what I could see). Nothing bad inside the tranny so that is as far as I went.

I don't get any grinding going into 1st or 2nd while driving so I think the syncros are good. When it doesn't go into gear, it just will not budge. No grinding into gear, just like hitting a wall with the shifter.

Could it be the bearings on the input cluster or between the input and output cluster. I thought if they had too much slop, there could be a slight misalignment in the gears. Could it be the shifter rail binding? Doesn't give me a problem when moving, though.

I know the biggest cause of this type of problem is clutch related, but since I have new parts in the clutch, I'm thinking it's elsewhere.

What you are describing was the way we used to shift tranis into first gear in the Old days... before 1st gear synchros

we used to always 'hit' an upper gear before putting it in 1st.
Maybe you misaligned something while replacing 5th gear parts?

When it's rolling, I can down shift into 2nd and even 1st as I slow down and there is no grinding. That makes me think the syncro's are good. Maybe they are just worn too much to shift it from a stop.

The 5th gear replacement was all in the tail housing section with the reverse gear. I didn't go into the main section where 1st thru 4th are.

I guess I have to pull either way. Maybe I'll do bearings and syncro's together just to cover all bases.

I think I might put a body lift on it at the same time. Sure would make tranny removal easier.

From a stop, what happens if you double Clutch then attempt to put it in first?

Tony H said:

From a stop, what happens if you double Clutch then attempt to put it in first?

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Doesn't help it. I can only shift into a higher gear and then it goes into 1st. There are times when the higher gears I noticed are starting to feel a bit stiff to engage but not like 1st or 2nd gear and only while stopped.

re bleed the system...

catfisher81 said:

re bleed the system...

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I think that is it.

I bled the clutch this morning and that made a big improvement. I don't think I got it perfectly bled, but close.

I'll drive it a bit and try to bleed it again and see if I can get it better. If can't get it 100%, I'll buy a new master cylinder since that is the only part of the clutch that isn't new.

Here is an update.

After bleeding the clutch master/slave, I thought I felt an improvement. I drove it for a while and realized no improvement. Still stiff getting into 1st or reverse from a stop.

Looking around today, I notice the floor mat is worn down under the clutch pedal to the point of showing through to the metal cord/rim. I pulled the mat out and with the extra 1/8th to 1/4 of an inch of travel on the clutch I can now shift into any gear easily from a stop. I think the clutch rod or master cylinder may be worn just enough that it needs that extra travel to completely release the clutch plate.

I think I'll drive it for a while without the floor mat before replacing the master cyl. Just to be sure (and to hope for some warmer weather).

Well the floor mat removal fix didn't last longer than two test drives. (I didn't think it would)

I bought a new clutch master cylinder and did the bench bleed procedure. It felt a lot stiffer than the old one so that was promising. Got it all installed, bled the entire system a couple times. Same problem.

I then pulled the new master and re-bench bled it figuring I missed some air. Didn't get any air out of it. Reinstalled and re-bled the entire system. Then gravity bled about two reservoirs worth of fluid. Same problem

Maybe the new slave cylinder I bought is bad. Maybe the tranny syncros are too worn. I don't know and getting frustrated.

It's the synchros....been there, done that.

I've rebuilt the M5OD a few times.....it's not a job for the novice...

Ryan

I'm still trying to figure exactly what's wrong. I am planning on pulling tranny, but I want to try to narrow down the problem a bit more so I am not just replacing parts blindly.

I had synthetic atf in the tranny from when I did the 5th gear replacement. I drained that and put regular mercon atf to see if that made any difference. Still the same problem.

Today I tried something while driving it. At a stop with the tranny in neutral, trying to shift it into 1st and feeling the same resistance, I noticed that if I blip the throttle it will go into gear. I am thinking that would rule out the slave cylinder as the problem. I seem to think that would point to the pilot bearing, or perhaps the bearings on the input shaft inside the tranny.

I'm not sure if that would rule out the synchros, but if I have the tranny out and change bearings, I'll probably put new synchros in as well.

Same here

Hey,

I've been having identical problems with my 97 for about 25000 miles now. It sucks, nothing seems to fix it. I finally took it in to the mechanic who bled it and gave it back to me saying not to use the heavy floor mat that I have. It was okay for awhile, but always goes back to being a royal pain. Never gets worse, but never all the way better. I have the recipt from the previous owner's clutch job at about 80K miles, everything replaced but the master cylinder. I was hoping that was my culprit, but reading your post has me back to square 1.

Even stranger, I live in Denver at around 5400 ft. Occasionally when I take the truck up in elevation, say 9 or 10,000' the clutch pedal goes totally dead, like the system is full of air. If I pump it a dozen or so times it will build up pressure again and hold it. On other occasions I'll return from high altitude and the pedal will get nice and firm for a day or so and the truck shifts great.

My problem is worst when going from neutral to 1'st at a dead stop, but for me, hitting 4th first then 1'st usually dies the trick. If I downshift it into 1'st while still barely rolling just before coming to a complete stop it will go, but it's dragging, the clutch isn't fully disengaging. If I blip the throttle sometimes it lets go. Sometimes I'll jerk it quickly into 2'nd, but it seems to like to "grab" there too and try to engage. For whatever reason I can almost always hit 4th at a dead stop and then throw it in 1'st.

The 1-2 upshift is generally a royal pain too, it's usually equally difficult whether I clutch the shift or "float" it. Brute force works, but I get the clunk noise. About 1/2 the time I get a slight grind going into reverse as well.

I hate this problem, but after having lived with it for a year or so now, tried what you have tried to fix it to no avail, the only thing left to do is pull the transmission and start over, doing everything myself so I know what parts get put in and that no corners get cut.

I am in the same boat as you at this point, completely stumped. Why I occasionally, and only occasionally lose pedal pressure/ feel at altitude is beyond me. It has to be air in the system somewhere, it's the only thing that makes sense, but there's more than one of us left scratching our heads over what to do about it.

My '93 Explorer has exactly the same symptoms, and so did the '95 Cherokee I used to have too. The Cherokee would be completely normal unless the clutch heated up... such as after a lot of stop-and-go traffic. It would get so bad that it would just not let you in 1st no matter how hard you tried, and reverse would grind BAD. Shifting between gears during those times had to be timed with the RPMs in order to get the shifter into the next gate, and even then it would be very clunky.

Now the Explorer does the same thing, except that it does it not as bad, but pretty much all the time. It gets a little worse after working the clutch for a while, heating it up, but even cold, it's still resistant. It's never gotten as bad as my Cherokee used to though.

It's funny, I read these exact same threads in the Jeep forum I use for my Cherokee and Wrangler, and you'd think with so many people having the same problem with so many different/unrelated vehicles someone would have figured this out definitively by now.

I'm still driving mine like it is. No problems as long as I downshift into first before coming to a stop.

Here is something mine does which makes me believe it's in the tranny and not the pilot bearing, clutch or slave cylinder. If I have it in first and come to a stop, I can hold the clutch in and move the shifter into neutral and it will always go back into first no matter how long I leave it in neutral. (So long as I hold the clutch in, the whole time) ...If the slave cyl. was bad causing the clutch to slightly grab, it would grab it while in neutral and should make it hard to go back into first, correct?

My clutch pedal has always had the same, decent (lightly firm) feel.

I'm betting on mine being synchro's and/or bearings in the tranny. Gonna pull it sometime soon, just putting it off due to laziness (being it's a pain).

jwv3 said:

I'm still driving mine like it is. No problems as long as I downshift into first before coming to a stop.

Here is something mine does which makes me believe it's in the tranny and not the pilot bearing, clutch or slave cylinder. If I have it in first and come to a stop, I can hold the clutch in and move the shifter into neutral and it will always go back into first no matter how long I leave it in neutral. (So long as I hold the clutch in, the whole time) ...If the slave cyl. was bad causing the clutch to slightly grab, it would grab it while in neutral and should make it hard to go back into first, correct?

My clutch pedal has always had the same, decent (lightly firm) feel.

I'm betting on mine being synchro's and/or bearings in the tranny. Gonna pull it sometime soon, just putting it off due to laziness (being it's a pain).

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i hate when you do all that work and find out you gotta take it all back out again. keep us posted and let us know what the problem was.

Does the transmission have the plug in hydraulic line fitting for the slave cylinder? If so pull it out and make sure the inside of the fitting is moving in and out properly

There are videos out there showing an off the vehicle master cylinder and line bleed, I had to do this to get my clutch working correctly. Master cylinder points down hill and hydraulic line goes down to the outside of the frame rail, then up and over and back down on the inside to the transmission. Horrible design.

@jwv3

If you pull the transmission out, check the thickness of the new clutch disc you put in. If it's significantly thicker than the old one, that can cause incomplete clutch release, exactly as you are seeing it. Also, if very much "meat" was removed from the flywheel, it will require excessive throw-out travel necessary to fully release the clutch; same symptoms. imp