94 B3000 V-6 5Speed Manual wierd shifting issue that maybe went away

[caliskier]

Hey all, I have a 5 speed manual that had had an issue a month ago that I need help with. Because of this issue i have not driven it until today.

For a couple of days before the incident I was hearing a squealing / chirping / clicking sound from the engine compartment when backing up, kinda loud. I ignored it, its and old truck and I thought is was just a rattle. I drove it 30 miles to a feed store and when I entered the parking lot I felt like I could not shift it. I loaded it up with about 800 lbs of equipment and tried to leave. It would not shift into gear and the clutch peddle felt like it was not doing anything. The shifter would not budge. I finally figured out that if I turned the engine off it would shift into gear. I was able to get it in first and get it started and the car did lurch forward because it was in gear and I did not feel any peddle. I was able to drive it home on the freeway shifting all the way to fifth. I did notice that the truck seamed to struggle holding 60 mph on the freeway after a while, but it was loaded with 8 40lb bags of fertilizer and 44 bottles of pool chlorine.

so I don't know what the issue was, I just drove it about 1 mile testing it around my block, getting up to 40 mph, it seamed to have power, and seamed to shift ok, maybe stick a little at first.

I have checked the clutch master cylinder fluid level - it was fine
I have checked the transmission fluid level - black and watery feeling, but full.

What do you guys think this could be?

 

[sheep herder]

Transmission fluid shouldn't be black and watery feeling.

 

[caliskier]

Transmission fluid shouldn't be black and watery feeling.

Agree, do you think that might be a cause of this issue?

 

[Bgunner]

The M5OD trans uses automatic trans fluid and not gear oil. It should not be black so it wasn't serviced any time recently for sure.

Shifting issue sounds clutch, master cylinder or the slave not working properly. This is where I would focus my diagnostics to start with.

 

[pjtoledo]

throw out bearing grabbing the input shaft? makes it jump or creep at a light. hard to get into 1st when stopped?
something to check.

edit: pilot bearing is what I should've said

 

[caliskier]

The M5OD trans uses automatic trans fluid and not gear oil. It should not be black so it wasn't serviced any time recently for sure.

Shifting issue sounds clutch, master cylinder or the slave not working properly. This is where I would focus my diagnostics to start with.

No, has not been serviced in 15 years I assume, maybe longer, bad on me. Would changing it make a difference?
That would be heaven, if is the master or slave. I assumed it was good because the fluid level was good. How can I diagnose that as the issue or eliminate it?

throw out bearing grabbing the input shaft? makes it jump or creep at a light. hard to get into 1st when stopped?
something to check.

Not sure, it does not jump or creep at least not now, just that one time, but I have only driven it once since. Is there a way to diagnose that without pulling the tranny?

 

[pjtoledo]

actually I meant to call out the pilot bearing.
pilot bearings only act up when the clutch is depressed.

 

[caliskier]

actually I meant to call out the pilot bearing.
pilot bearings only act up when the clutch is depressed.

I believe the pilot bearing is down in the center of the clutch plates.

How can I diagnose these issues, especially the slave and master cylinders? Would be a much easier fix if its that.

 

[Bgunner]

There is an inspection plate/big rubber plug that and be removed on the bell housing that allows you to see into the clutch area. Pull plug and look to see if any fluid is leaking from the slave cylinder. Have some one depress the clutch pedal and check for proper movement of the slave and throw out bearing.

If leaking replace if not and slave moves the full amount then the culprit would be more likely the master cylinder. My guess without looking is this would be the most likely cause of your issues.

Changing fluid will help it shift smoother and extend the life of the trans but will hot help the loss of the clutch.

Reasoning for bad hydraulics on clutch as you described:

1. At a dead stop with engine running you could not put it gear; this indicates the clutch is not disengaging.

2. When a slave starts to go without a leak you can most times get a pedal back by pumping the pedal a bunch of times to build pressure to get it to disengage.

3. Random working and not working and not getting a pedal after pumping usually indicates a master cylinder's internal seals went bad.

 

[caliskier]

There is an inspection plate/big rubber plug that and be removed on the bell housing that allows you to see into the clutch area. Pull plug and look to see if any fluid is leaking from the slave cylinder. Have some one depress the clutch pedal and check for proper movement of the slave and throw out bearing.

If leaking replace if not and slave moves the full amount then the culprit would be more likely the master cylinder. My guess without looking is this would be the most likely cause of your issues.

Changing fluid will help it shift smoother and extend the life of the trans but will hot help the loss of the clutch.

Reasoning for bad hydraulics on clutch as you described:

1. At a dead stop with engine running you could not put it gear; this indicates the clutch is not disengaging.

2. When a slave starts to go without a leak you can most times get a pedal back by pumping the pedal a bunch of times to build pressure to get it to disengage.

3. Random working and not working and not getting a pedal after pumping usually indicates a master cylinder's internal seals went bad.

Thank you Bgunner. I believe everything you just described does not involve pulling the transmission. Thank you very very much for your time. This is my beat up truck, I drive it about 20 times a year for trips to the lumber yard or just to keep the fluids and battery good. I was on the fence about dumping it, fixing it myself, or having it done. A clutch replacement is $1,200 so that's out, and I don't have the time to do that work myself. A master cylinder or slave cylinder I have the time for.

 

[Bgunner]

The slave cylinder replacement on m5od transmissions does require the trans to be pulled back from the motor due to it being inside the bell housing. So if you need a slave and the clutch is worn that is the time to do it all.

 

[caliskier]

The slave cylinder replacement on m5od transmissions does require the trans to be pulled back from the motor due to it being inside the bell housing. So if you need a slave and the clutch is worn that is the time to do it all.

what about the master?

 

[Bgunner]

The master is able to be done without removing the trans but be aware that these get burped and not bled like others. I belive in the tech section there is a link to a video on how to burp them before install. If you dont burp them before install you can get an air bubble trapped that just wont come out and you need to remove it and the line to burp it.

After master install you gravity bleed the slave to bleed that part and you should be all set.