4.0L Manual 5 Spd

[Buckeyeman]

I got my truck back and they darn near replaced everything in the transmission with new parts. The invoice shows synchronizers, synchro rings, bearings, seals, input shaft, sleeves, and replaced pilot bearing and bleed clutch. It seems to upshift a lot smoother. It still seems to downshift kinda hard into 2nd and 1st though. IMO I don't think this was the best engineered trans. from Mazda.

 

[pcollins]

The M5OD is a very good trans with a proven track record. For one to blow any earlier than around 250k miles is not typical.

 

[4x4junkie]

The slave can have an internal leak as well and you wouldn't see it. This was the issue on my first ranger. I had absolutely NO noticeable fluid loss and the bell housing was dry. But when I took the T/O bearing off there was just a tiny bit of fluid in there causing my issue.

If the problem lies in 1st, 2nd and 3rd and not 4th then I don't think your problem lies in the synchro's. It is a slave cylinder/clutch problem like PCollins said. Although it may not be leaking externally it may be passing by internally. With that low of mileage I would be hard pressed to say that your transmission has anything wrong with it at all. The first rebuilt of my M5OD-R1 in my 92 was at 290,000 and it cost a toal of $430 in parts and me rebuilding it. As long as it has never been run low or out of oil 80,000 miles is close to the life span of the slave though. If you do the slave may as well replace the clutch as you are already there.

You guys claiming it's a "slave problem", can you explain how the fluid could possibly pass through to anywhere but the outside?

There are two concentric seals around the OD and ID of it's piston, and both of them seal the piston from the inside to the outside. Any leakage past either one of them will most certainly be to the outside, and will of course be visible.

An internal leak certainly can be possible in the MASTER cyl, but not in the slave.

 

[Buckeyeman]

The only thing I really noticed is the shifter has a lot more wobble now in gear then it did before. It use to be pretty tight before.

 

[-Nathan-]

The M5OD is a very good trans with a proven track record. For one to blow any earlier than around 250k miles is not typical.

I strongly disagree. Yes it is the better of RBV trannies. This may be true in a stock truck, but the minute it sees larger tires/wheeling abuse, I have seen lots fail. Split output housings, tailshafts, synchros and bearings always $hit the bed, etc. The engine, tcase, axles all held up great, but I could eat trannies if wanted to.

 

[pcollins]

I strongly disagree. Yes it is the better of RBV trannies. This may be true in a stock truck, but the minute it sees larger tires/wheeling abuse, I have seen lots fail. Split output housings, tailshafts, synchros and bearings always $hit the bed, etc. The engine, tcase, axles all held up great, but I could eat trannies if wanted to.

The transmission wasn't engineered to withstand all the upgrades. So you cant really complain when it blows out from under a non-stock truck.

Now something like a raptor, those are engineered to eat shit all day long and keep ticking.

 

[pcollins]

You guys claiming it's a "slave problem", can you explain how the fluid could possibly pass through to anywhere but the outside?

There are two concentric seals around the OD and ID of it's piston, and both of them seal the piston from the inside to the outside. Any leakage past either one of them will most certainly be to the outside, and will of course be visible.

An internal leak certainly can be possible in the MASTER cyl, but not in the slave.

How can i claim it? cause it happened directly to me. Itd work fine for the first 5 minutes then act up when it warmed up. Upon dissasembly i found this:

In the top picture around the black ring the shiny stuff is DOT3. And on the bottom picture, around the gray ring. It was enough to give me issues shifting, but not noticeable at all in the bell housing or fluid level. And very small drips would get soaked right up by the dirt/clutch dust etc that gathered in the bellhousing over the 15 years of the trucks life.

 

[tx3nc]

The only thing I really noticed is the shifter has a lot more wobble now in gear then it did before. It use to be pretty tight before.

Is it possible they didn't change the shifter bushings? After such an extensive rebuild, I'd be surprised if they didn't.

 

[4x4junkie]

The only thing I really noticed is the shifter has a lot more wobble now in gear then it did before. It use to be pretty tight before.

Agreed, that does sound like the shifter bushings. Maybe they left one or both out?
Or maybe they failed to fully tighten the bolt that holds the stick handle to the trans?

How can i claim it? cause it happened directly to me. Itd work fine for the first 5 minutes then act up when it warmed up. Upon dissasembly i found this:

http://i258.photobucket.com/albums/hh273/ptchunter16/oldclutchstuff.jpg
http://i258.photobucket.com/albums/hh273/ptchunter16/oldclutchstuff6.jpg

In the top picture around the black ring the shiny stuff is DOT3. And on the bottom picture, around the gray ring. It was enough to give me issues shifting, but not noticeable at all in the bell housing or fluid level. And very small drips would get soaked right up by the dirt/clutch dust etc that gathered in the bellhousing over the 15 years of the trucks life.

That tiny miniscule amount of leakage is very unlikely to cause a shift issue... To cause an issue the leak has to be big enough to allow the reservoir to drain down, finally sucking air into the system.
Possible you had another problem causing it and it was just coincidence?
I've seen shifting issues on (earlier) M5ODs that appeared to be from use of Mercon V fluids rather than Mercon... maybe that could've been your issue? (just throwing another possibility out there)

I strongly disagree. Yes it is the better of RBV trannies. This may be true in a stock truck, but the minute it sees larger tires/wheeling abuse, I have seen lots fail. Split output housings, tailshafts, synchros and bearings always $hit the bed, etc. The engine, tcase, axles all held up great, but I could eat trannies if wanted to.

So far all of mine and my buddy's have been doing fine, knock on wood (my buddy's is the highest with 190K, mine have ~106K (Ranger) and ~150K (BII).
If you're properly regeared for the bigger tires, they shouldn't affect anything ahead of the axles.

 

[Buckeyeman]

Is it possible they didn't change the shifter bushings? After such an extensive rebuild, I'd be surprised if they didn't.

Thanks guys for the replies. I called the dealer and they want me to bring it by next week so the mechanic can see what I'm talking about. I was kinda thinking on the same terms that they left something out like the shifter bushings.

 

[pcollins]

Agreed, that does sound like the shifter bushings. Maybe they left one or both out?
Or maybe they failed to fully tighten the bolt that holds the stick handle to the trans?




That tiny miniscule amount of leakage is very unlikely to cause a shift issue... To cause an issue the leak has to be big enough to allow the reservoir to drain down, finally sucking air into the system.
Possible you had another problem causing it and it was just coincidence?
I've seen shifting issues on (earlier) M5ODs that appeared to be from use of Mercon V fluids rather than Mercon... maybe that could've been your issue? (just throwing another possibility out there)




So far all of mine and my buddy's have been doing fine, knock on wood (my buddy's is the highest with 190K, mine have ~106K (Ranger) and ~150K (BII).
If you're properly regeared for the bigger tires, they shouldn't affect anything ahead of the axles.

That slave was the issue. I think it would suck small amounts of air in via the leak and bleed its self back out the same way. I never even drained the fluid out of the trans when I changed that slave, so that wasn't the issue. I replaced that slave and never had an issue with it for over a year. Its sold now but was working fine when i got rid of er.

 

[rboyer]

That's a common issue with those slave cylinders. I've seen it atleast a dozen times before. All of the local garages just tell people that their transmission is shot. In the past i've probably talked atleast 100 people OUT of buying a transmission from me just because of a tricky little slave cylinder.

 

[Buckeyeman]

The only thing I really noticed is the shifter has a lot more wobble now in gear then it did before. It use to be pretty tight before.

I took my truck back to the dealer and the pinch bolt that holds the shifter was never tightened. The mechanic said its a good thing you brought it back cause the shifter could have come off in your hand. Everything is back to normal now.