Ok, this is going to be long because I need to give history before asking what's wrong. I have a 94 Ranger XLT 4x2 ext cab with 5 speed with about 220K. About 2 years ago I had the clutch done and up until recently I have had very few problems with shifting. Last summer I was losing fluid through the plugs and I started to have issues with getting into 3rd and 5th. I kept tabs on the fluid level and topped off often and I didn't hesitate on replacing those plugs when I found out that was the issue. Last summer I was also having excessive heat coming from the shift area as the heat guard was ripped away by the previous owner PLUS I was having engine cooling issues so I pretty much replaced EVERYTHING and flushed the system, but when I got to the radiator it was caked, packed about half way up with dirt between the trans cooling fin and radiator so I cleaned that all up and replaced the radiator. Well, now I basically am mystified at how the tranny is acting. When cold, 1st start of the day, it'll shift into all of the ears nice and smooth, no problems at all. Give it about 15-20 minutes of driving and I'm having issues in all gears randomly. SOOO, I crawl under and my GF steps on the clutch while I'm looking into the bell housing and the slave is pushing the plate pretty good. Clutch peddle isn't spongy or anything. BUT, just to be safe (and because the parts were on warranty) I decide I'm going to replace the master cylinder and I pull the old one out and start bench bleeding it, install it and hose and grav bleed two reservoirs worth of DOT 3 then for extra another reservoir via peddle (did get more out that way as well) So I take the truck out and return the old master and it's shifting pretty smooth. Again this morning until about a half hour later and all of a sudden BOOM, it starts acting the same, but worse. What I'm not understanding is why it would only act up some times instead of all of the time? I can be at a red light (twice today) and have to start in 2nd cause it won't go into 1st then for 10 minutes shift in all gears fine then all of a sudden it starts rejecting random gears again. I've had this truck for 2 and a half years and like it allot and I really don't have much of a choice but to fix it because of a child support lein. Besides that It's MY POS, But I am getting to my last end with it. I can't keep guessing and I need some serious help. REMEMBER, cold it shifts great while driving with NO issues in any gear.....

 

Welcome to the forum


You don't say but you are using Mercon ATF(automatic transmission fluid) in your M5OD-R1 manual transmission right?

Not going into 1st when stopped is a clutch issue FOR SURE, no question about it

When you are stopped the transmission is at 0 RPMs, has to be because there is no way to disconnect transmission from back wheels.
The clutch disconnects the Engine from the transmission

When you are stopped and engine is idling at say 700RPMs, trans in Neutral
The input shaft of the transmission is at 700 RPMs as well, output shaft and Dog Gears are at 0 RPMs
You push in the clutch pedal so clutch disc and input shaft can slow down to 0 RPMs so you can put transmission in to a gear, any gear really, but input shaft HAS TO go down to 0 RPMs for that to happen.
Once you get it in to any gear, disc and input shaft are at 0 RPMs, higher gears like 3rd and 4th are often easier to shift into when stopped because of the ratios.
But once stopped you should be able to shift into 1st easily from 2nd, 3rd, or 4th because disc and input shaft is at 0 RPMs, see if you can.

If there is ANY rubbing from flywheel or pressure plate on the clutch disc then it becomes very hard for the 4" synchro ring(in the trans) to slow down the 10" clutch disc to 0 RPMs.
This is why air in the system is an issue, pressure plate rubs disc unless released all the way.
Clutch disc "floats" on input shaft splines, if it starts to bind and not slide it can stay in contact with flywheel or pressure plate, this rubbing causes hard shifts because input shaft is not free to match transmission RPMs

There is also the Pilot bearing at the end of the input shaft, input shaft is supported at one end by the flywheel/crank, the pilot bearing allows the input shaft to change speeds, i.e. slow down to 0 RPMs while flywheel/crank stays at 700 RPMs
If this bearing starts to bind then it becomes hard to change input shaft RPMs to match transmission RPMs.

You may try draining trans fluid and use a synthetic brand, now that rail plugs are fixed.
Many swear by it, never tried myself.


Hard to say about the cold and warm changes, usually cold trans fluid makes for stiffer shifting, warm better, yours is opposite.
Could be an issue in clutch system that is causing warm parts to bind a bit more.

If transmission shifts OK with engine off, then I wouldn't suspect a transmission problem, it could be, I have no crystal ball, just more likely to be a clutch problem from description.

 

"You don't say but you are using Mercon ATF(automatic transmission fluid) in your M5OD-R1 manual transmission right?" yes and M5R1 I believe

"When you are stopped the transmission is at 0 RPMs, has to be because there is no way to disconnect transmission from back wheels.
The clutch disconnects the Engine from the transmission" yes, at least I believe it is, I only grind gears when I go into rev. sometimes. All I know is that when I press the clutch I stop accelerating so I believe the tranny is at 0 RPM

"Once you get it in to any gear, disc and input shaft are at 0 RPMs, higher gears like 3rd and 4th are often easier to shift into when stopped because of the ratios.
But once stopped you should be able to shift into 1st easily from 2nd, 3rd, or 4th because disc and input shaft is at 0 RPMs, see if you can." IF I can get it into 2nd yes, it'll go into 1st from there.

"If there is ANY rubbing from flywheel or pressure plate on the clutch disc then it becomes very hard for the 4" synchro ring(in the trans) to slow down the 10" clutch disc to 0 RPMs.
This is why air in the system is an issue, pressure plate rubs disc unless released all the way.
Clutch disc "floats" on input shaft splines, if it starts to bind and not slide it can stay in contact with flywheel or pressure plate, this rubbing causes hard shifts because input shaft is not free to match transmission RPMs" So? More bleeding? Maybe a vacuum pump bleed?

There is also the Pilot bearing at the end of the input shaft, input shaft is supported at one end by the flywheel/crank, the pilot bearing allows the input shaft to change speeds, i.e. slow down to 0 RPMs while flywheel/crank stays at 700 RPMs
If this bearing starts to bind then it becomes hard to change input shaft RPMs to match transmission RPMs. I did forget to mention a kind of hum in 5th, could this be the issue?

If transmission shifts OK with engine off, then I wouldn't suspect a transmission problem, it could be, I have no crystal ball, just more likely to be a clutch problem from description. Yes, with engine off it shifts into all gears fine, 4th without the clutch & engine off has a double click I noticed today but slides in with clutch depressed

 

Also, if I'm more than likely going to be changing the tranny fluid, what's your opinion on Royal Purple? My engine does like the RP oil allot, but I'm curious about the tranny fluid. I've done a passive search but couldn't find anything. I am using regular Mercon V ATF now.

 

M5R1 is the short version of M5OD-R1, M5OD-R2(M5R2) were used in full size trucks, i.e. F-150, 250 ect....

These transmission were used from late 80's to end of Ranger line in 2012, outside of the leaking rail plugs they were pretty solid transmission, you can of course have problems with any transmission, it's just with the M5R1 it would be the last place to look.

M5R1 is full synchromesh, even Reverse has synchro so should never grind, this would again lead me to believe there is a clutch problem.

If you are moving the transmission is spinning at driveshaft RPMs/wheel RPMs, clutch in or out doesn't matter.
Clutch is there to match Input Shaft RPMs with Driveshaft/wheel RPMs(transmission RPMs)

If Royal Purple makes an ATF then give it a try

Simple test for clutch is to drive at about 10mph and push in the clutch, shift to Neutral and let out the clutch, this will get input shaft spinning at engine RPMs
Push in clutch again while still moving and see if it shifts into 1st easier
When you are rolling, even a little, then input shaft doesn't need to get down to 0 RPMs
So if it shifts into 1st easier you will know its a clutch issue not trans issue.

Yes you can rebleed, also have someone press down on clutch pedal while you feel the master hose going down to the slave, defective or older hose can start to expand instead of staying tight, which, of course, means less travel for the slave

 

Ok, I can give them a try. but it'll be a couple of days because of a snow storm coming through.

One more point I forgot to make is that the clutch fluid was pretty dirty and we bled it till it came out clear, but I'm wondering if maybe something (dirt, debris, tiny black rubber specs) is stuck?

Yes, RP does have a ATF, BUT I'm nervous about using anything other than what is recommended, but I did check what I put in was Merc V

IF you, or anyone else think of anything else, please let me know, thanks

 

[B]UPDATE[B] Ok, had some halfway decent weather (for Wisconsin this time of the year) I did a vac. bleed from the clutch res. just to make sure I had no air there and then did a vac. bleed at the slave and I'm not sure because it was hard to get a good fit on the bleed screw with the cold, but I'm sure I seen plenty of air come out. Closed it all up, cleaned up and drove it. MUCH better, but not completely. I did bleed through 2 reservoirs of fluid and managed to get all clean fluid. I got about twice as far as normal before it did start to reject gears again, but not nearly as bad as before. My conclusion is that I may need to replace the line to the slave, that somehow air is getting sucked back in. Still factory line at 220K. I'm not seeing any spots and I'm not going through any fluid. BUT upon bleeding I did notice a stiffer peddle and better shifting.

And as far as getting into 1st gear, I never could get it into 1st when moving more than a rolling stop. I always stop in N with foot off the clutch. IF I'm rolling I always have to go into 2nd to keep moving so I couldn't check the 10 mph. It's been that way since I've had it going on 2 and a half years now.

Thoughts? Feedback?

 

It very well sounds as if the hose could be collapsed internally.....I would say @220k I would replace the hose, it's already lasted a lifetime keep us posted as to the outcome.....

 

I will. That's pretty much what we were thinking too about the hose. So far it's been acting up very little in comparison to before. I'm just dreading getting the master cylinder off again to replace the hose. We will keep you posted.