1995 Ford Ranger Worn syncros

[BobC]

Hello
I have a 1994 Ford Ranger 4.0 liter, 5 speed manual, 189,000 miles.
When the transmission is warm the transmission grinds when shifting into 1st and 2nd gear.
When the vehicle is cold the transmission shifts fine.
It shifts better for a longer period of time when the outside temperature is lower
I am assuming this is because the fluid is a little thicker when at a cooler temperature, as soon as it warms up shifting is more difficult.
I know the proper fix is to rebuild the transmission, but I am hoping there is a way to increase (thicken) the transmission fluid (Mercon V) to
improve shifting after the tranny warms up. Or is there a Mercon V or alternative that has a higher viscosity?
Tks Bob

 

[Lubener]

Myself, I would either try changing the fluid (if it's original) with Mercon V or try replacing the existing fluid with a 75w-90 gear oil.

 

[Olds394]

MolaKule published a list that would be a real help to you. I think I searched m5od fluid, or something similar.

 

[demarpaint]

You have the Mazda M5OD transmission. When was the last time you bled/exchanged the brake fluid in the slave cylinder? Brake fluid takes on moisture and will cause the clutch to not fully release, especially when things get hot. I gravity bleed mine every 2-3 years with fresh new DOT3 brake fluid, it does make a difference, and in my case stopped the occasional grind while shifting and shifting into reverse. In fact if I get lazy and forget to bleed the clutch [more than 3 years] it will remind me with a grind. I also found Mobil Delvac 1 ATF to be the best for it, thanks for that pick goes to @Trav . It operates flawlessly with it.

Before trying gear oil or rebuilding the transmission gravity bleed the clutch, run at least 1/2 a quart through it. Don't let the little reservoir run dry while doing it.

If your synchros are shot a rebuild is the only thing that will fix it, or double clutching might help. Good luck.

 

[vwmaniaman]

My manual transmission cars have all been fixed of that problem by adding a half quart of Lucas. My son suggested it so I tried it and it worked.

 

[Fordiesel69]

You have the Mazda M5OD transmission. When was the last time you bled/exchanged the brake fluid in the slave cylinder? Brake fluid takes on moisture and will cause the clutch to not fully release, especially when things get hot. I gravity bleed mine every 2-3 years with fresh new DOT3 brake fluid, it does make a difference, and in my case stopped the occasional grind while shifting and shifting into reverse. In fact if I get lazy and forget to bleed the clutch [more than 3 years] it will remind me with a grind. I also found Mobil Delvac 1 ATF to be the best for it, thanks for that pick goes to @Trav . It operates flawlessly with it.

Before trying gear oil or rebuilding the transmission gravity bleed the clutch, run at least 1/2 a quart through it. Don't let the little reservoir run dry while doing it.

If your synchros are shot a rebuild is the only thing that will fix it, or double clutching might help. Good luck.

+1, this fixed my old 1986 F150. The brake fluid was contaminated and would not disenguage the clutch when the engine bay warmed up.

 

[SwampSurvivor]

You have the Mazda M5OD transmission. When was the last time you bled/exchanged the brake fluid in the slave cylinder? Brake fluid takes on moisture and will cause the clutch to not fully release, especially when things get hot. I gravity bleed mine every 2-3 years with fresh new DOT3 brake fluid, it does make a difference, and in my case stopped the occasional grind while shifting and shifting into reverse. In fact if I get lazy and forget to bleed the clutch [more than 3 years] it will remind me with a grind. I also found Mobil Delvac 1 ATF to be the best for it, thanks for that pick goes to @Trav . It operates flawlessly with it.

Before trying gear oil or rebuilding the transmission gravity bleed the clutch, run at least 1/2 a quart through it. Don't let the little reservoir run dry while doing it.

If your synchros are shot a rebuild is the only thing that will fix it, or double clutching might help. Good luck.

They have internal slave cylinders - is it even possible to bleed without pulling the transmission?

 

[demarpaint]

They have internal slave cylinders - is it even possible to bleed without pulling the transmission?

Yes, on the left side of the transmission there is a nipple you can bleed it from. Follow the line down from the clutch master cylinder to the slave cylinder the nipple is not far from there.

 

[SwampSurvivor]

Yes, on the left side of the transmission there is a nipple you can bleed it from. Follow the line down from the clutch master cylinder to the slave cylinder the nipple is not far from there.

Interesting, didn't know that!

 

[demarpaint]

Interesting, didn't know that!

A lot of people don't. If you do bleed it, get a turkey baster or large syringe and suck out about 3/4 of the fluid then fill it with fresh fluid. Crack the bleeder and have someone up top keep the reservoir topped up you don't want to introduce air into the system. You can do it yourself but it's a bit of a hassle. Once you ran at least 1/2 or more of a quart through it tighten up the nipple adjust the level in the reservoir put the cap back on and take it for a ride. Good luck!

 

[SwampSurvivor]

A lot of people don't. If you do bleed it, get a turkey baster or large syringe and suck out about 3/4 of the fluid then fill it with fresh fluid. Crack the bleeder and have someone up top keep the reservoir topped up you don't want to introduce air into the system. You can do it yourself but it's a bit of a hassle. Once you ran at least 1/2 or more of a quart through it tighten up the nipple adjust the level in the reservoir put the cap back on and take it for a ride. Good luck!

What about my external slave ZF-5 . Which apparently doesn't exist.

All that's available are ones without bleeders. Just have to press the clutch 5000000 times?

 

[demarpaint]

What about my external slave ZF-5 . Which apparently doesn't exist.

All that's available are ones without bleeders. Just have to press the clutch 5000000 times?

Can't help you with that buddy, I don't own one.

Regarding the M5OD bleeder nipple, it is slightly recessed, at least it is in my E-150, but I'm sure you'll find it.

 

[D60]

What about my external slave ZF-5 . Which apparently doesn't exist.

All that's available are ones without bleeders. Just have to press the clutch 5000000 times?

Theoretically you can vacuum bleed (your ZF or a Ranger) from the top. This guy's got questionable street cred but it's simple enough:


I actually did this on a '94 Ranger. I don't recall the results.

There's a host of vids about a stubborn low point in the clutch hydraulic system due to Team TFI's master cylinder location down low:

 

[nwjones18]

I've had synchromesh in my 88 F-150 for a couple decades now and it shifts better than it did with ATF. Give it a shot.

I like the comments on bleeding the clutch master cylinder.. I can say I've never done that on mine and have been driving it since 02. It did get a clutch around 09, but has had the same fluid in it since then..

 

[thastinger]

When the M50 tranny went out in my 88 Ranger I swapped in a T5 from a turbo coupe and never had anymore issues.

 

[BobC]

Thanks for so many good suggestions I will have to do some cogitating to determine which to try first.
I replaced the clutch and throw out bearing about a year ago and was very cautious about bleeding because the known difficulties purging the system.
The t5 swap sounds interesting. If I can put that off for a while with a little thicker fluid, I would like to try that first