Techs! Tranny/Clutch Problem

[Nova Kaw 650]

I'd like to get this done this week.
Here come the troubleshooting clues:
1999 Ranger, 3.0, 5 speed 4X4, lots of miles.
My brothers truck; it was shifting hard between gears a couple of years ago, until it wouldn't go into gear when sitting still, so he took it to a local shop. They replaced the clutch/PP, and slave, then went through the usual horror of trying to get it bled.
Clue #1- it was acting exactly the same, but after repeated bleedings, it finally worked.
It lasted for a year and started doing the same thing. He bought another truck and wants to get this working so he can sell it. He's bringing it to me, and after a 1/2 hour of questioning (he has ZERO mechanical aptitude), this is what I have:
Clue #2- it's doing the exact same thing again.
Clue #3- VERY important; when he shuts it off to get it into 1st gear (practically falls into gear) and restarts the engine with the clutch in, the truck doesn't try to creep; in fact, he has to let the clutch out about an inch before the truck starts to move again.
That says to me that it has nothing to do with bleeding; it appears that the clutch control mechanism is doing what it's supposed to do. What it does indicate is that the clutch disc and input shaft are still turning, even though the pressure plate should be released.
I'm thinking that either the clutch disc isn't sliding on the input shaft splines, therefore dragging on the flywheel, or the pilot bearing is shot.
Has anyone seen this, or have any opinions.

 

[Earl43P]

Still sounds like a bad slave or master to me.
Pull the rubber cover off the driver side, you can see in there.

Also, to somewhat confirm it's the slave or air,
engine off: depress clutch, slip foot off pedal letting it return up on its own.
Repeat several times, then drive it.
Clutch might work for a day after that, might not work at all, might work for months.

Welcome to The Ranger Station!

If it were mine, plus knowing the slave has been replaced, I'd throw a $60 Master on there. It's not that hard to snake the line in if you undo the back part of the fender inner liner. Bench bleed master before you install it, heck you can connect it to the slave without it being installed so you can bleed it by hand before you actually mount it.

I have a lot of faith in that quick disconnect fitting on the slave. I've bench bled the whole system, disconnected it, installed the slave and trans, installed the master, reconnected and it worked great, no bleeding required. Twice, 2 different 93s.

RockAuto had good prices on the Master, with a new line.

 

[RonD]

Could be the same issue again, it is a common failing with this transmission.

Look here
http://www.therangerstation.com/tech_library/ManualTransmission.html

1999 Ranger with 3.0l will have the Mazda M50D-R1 5-speed

There is an off chance a repair shop would use the wrong oil inside so too thick of an oil making shifting harder, but I also think that would slow down the input shaft.

With wheels stopped the only rotational input for the transmission is from the engine, so unless the syncro can stop the input from engine it won't go into gear.
The syncro gear "rubs" against the output shaft to match speeds, if output shaft(wheels) are stopped then the syncro would stop the input shaft, unless engine is still connected via the clutch.
Yes, the input shaft sits directly against the flywheel and the pilot bearing allows the input shaft to stop spinning when clutch is engaged.
So yes if the pilot bearing has failed it might not allow the input shaft to stop spinning easily, at least not enough for the pressure from the syncro to stop it spinning.

You can usually tell if the input shaft is turning by trying Reverse, it has no syncro to match shaft speeds so will grind, if it goes into reverse easily while engine is running then clutch/pilot are OK, hard shifting is a problem in the transmission itself.
Another quick test is to stop engine, put trans in reverse then restart engine with clutch in, leave clutch in and move out of reverse then back into reverse, if it grinds try to go back into reverse then either clutch is not disengaging all the way or pilot bear is bad.

 

[Nova Kaw 650]

Clue #3- VERY important; when he shuts it off to get it into 1st gear (practically falls into gear) and restarts the engine with the clutch in, the truck doesn't try to creep; in fact, he has to let the clutch out about an inch before the truck starts to move again.

As above; would it be possible for the clutch to act normally for one cycle if there was a bad slave/master/air in the system?

 

[RonD]

I would lean toward the pilot bearing if input shaft continuing to spin is the issue.

But you think you would hear a noise from that bearing if crankshaft was turning and input shaft wasn't, i.e. wheels are stopped, trans is in gear with clutch in, so input shaft is stopped.

 

[adsm08]

I have given up on doing these slaves without a master cylinder and line. It is just inviting failure.

 

[feellnfroggy]

Sounds to me like air in the line, somewhere, or the bolts have backed out of the trans housing.

 

[aspevacek]

I'd like to get this done this week.
Here come the troubleshooting clues:
1999 Ranger, 3.0, 5 speed 4X4, lots of miles.
My brothers truck; it was shifting hard between gears a couple of years ago, until it wouldn't go into gear when sitting still, so he took it to a local shop. They replaced the clutch/PP, and slave, then went through the usual horror of trying to get it bled.
Clue #1- it was acting exactly the same, but after repeated bleedings, it finally worked.
It lasted for a year and started doing the same thing. He bought another truck and wants to get this working so he can sell it. He's bringing it to me, and after a 1/2 hour of questioning (he has ZERO mechanical aptitude), this is what I have:
Clue #2- it's doing the exact same thing again.
Clue #3- VERY important; when he shuts it off to get it into 1st gear (practically falls into gear) and restarts the engine with the clutch in, the truck doesn't try to creep; in fact, he has to let the clutch out about an inch before the truck starts to move again.
That says to me that it has nothing to do with bleeding; it appears that the clutch control mechanism is doing what it's supposed to do. What it does indicate is that the clutch disc and input shaft are still turning, even though the pressure plate should be released.
I'm thinking that either the clutch disc isn't sliding on the input shaft splines, therefore dragging on the flywheel, or the pilot bearing is shot.
Has anyone seen this, or have any opinions.

Ok let me touch on the sliding on the input shaft splines comment. The clutch disc does not slide on the shaft. The pressure plate applies pressure on the friction surface of the disc and forced it against the flywheel. When you push in the clutch pedal it applie spressure to the fingers on the pressure plate and pulls the pressure off the outer ring of the pressure plate. this is why when some one rides the clutch it will wear out alot faster as even a partial depressed clutch pedal will lower the clamping force on the disc allowing it to slip.
The pilot bearing not doing its job properly would keep the input shaft to teh trany rotating at the same speed as the engineand it would be liek a direct drive unit. I have seen it happen in the past but even with the pedal pushed to the floor the vehicle would attempt to creep forward becasue input was still being put into the transmission.

Now with air in the system it is like air in a brake system the air will compress where as the fluid will not. I would say throw a master cylinde on the truck and bleed the shit out of it.

 

[Nova Kaw 650]

Ok let me touch on the sliding on the input shaft splines comment. The clutch disc does not slide on the shaft. The pressure plate applies pressure on the friction surface of the disc and forced it against the flywheel. When you push in the clutch pedal it applie spressure to the fingers on the pressure plate and pulls the pressure off the outer ring of the pressure plate. this is why when some one rides the clutch it will wear out alot faster as even a partial depressed clutch pedal will lower the clamping force on the disc allowing it to slip.
The pilot bearing not doing its job properly would keep the input shaft to teh trany rotating at the same speed as the engineand it would be liek a direct drive unit. I have seen it happen in the past but even with the pedal pushed to the floor the vehicle would attempt to creep forward becasue input was still being put into the transmission.

Now with air in the system it is like air in a brake system the air will compress where as the fluid will not. I would say throw a master cylinde on the truck and bleed the shit out of it.

If the disc can't move at least slightly on the splines, then it can't
fully disengage. It would stay tight against the flywheel.

 

[Andy D]

If the disc can't move at least slightly on the splines, then it can't
fully disengage. It would stay tight against the flywheel.

The hub of the clutch has to move freely on the input shaft mainly to help ease installing the tranny. The web of the clutch flexes with the pressure plate a bit but the hub doesnt travel along the splines on a regular basis.

Another vote for bleedin the snot out of it. Unbolt the MC from the firewall so you can tip it, then open the bleeder. and let it drip until the bubbles go away. If that doesnt fix it, then buy new stuff and bleed it before you bolt it to the firewall

 

[aspevacek]

If the disc can't move at least slightly on the splines, then it can't
fully disengage. It would stay tight against the flywheel.

I am telling you the clutch disc does not slide on the input shaft. The splines are there for the inputshaft to engage. The clamping and releasing of the pressure plate allows the motor and tranny to rotate at the same speed or different speeds.

http://www.youtube.com/watch?v=FfjGohWy-OU

nice short video if how a clutch functions to help those who may not understand.

 

[pcollins]

Another vote master/slave being bad or needing bleeding. I had the same issue with my '97. Put in a brand new out of the box slave and bled it, had the same issue your describing in clue number 3 OP, it wouldn't go into gear easy but it wouldn't creep forward either. Turns out the slave had a very small leak on the inside. Just small enough to cause issues but not be seen. Anyways, after replacing the slave again (I had already bench bled the master at this point) I didn't try to bleed it like brakes this time around. I just cracked the bleeder screw on the slave loose, let it dribble out for about 30 seconds, closed the bleeder and drove the truck for another year without a problem.

 

[veefer800canuck]

i had to remove the master cylinder piston slightly, up inside the cab, in order to get the last bit of air out, despite pumping and bleeding down to the slave a LOT of fluid.

basically, I disconnected the clutch pedal, took the circlip out of the master cylinder, slid the master piston assembly out of its bore slightly and momentarily until a small amount of fluid gravity fed from the reservoir, then popped it back in, installed the circlip, reconnected the clutch pedal, then gave it another bleeding down to the slave for good measure.

its been working fine in daily use for almost a year after new clutch disc, pressure plate, and slave/throwout bearing (the swap necessitated the bleeding, despite the quick connector on the clutch line).