I bought a 2003 Ford Ranger, 2.3, 5 speed manual. It is hard to shift after it warms up. I test drove it when it was below freezing, so I didn't notice it at first. The warmer the day and quicker the truck warms up, the worse it is. It goes into gear with no problem when the engine is off or if I'm still moving, but if I'm stopped there are times it is hard to get into gear. This really sounded like a clutch that wasn't fully disengaging to me, so I decided to pull it apart. I didn't check the movement at the slave before I started, but I did find the master was a little wet at the rod in the cab.

So, I did the following:

- New clutch master cylinder (system bled out of truck to eliminate air)
- New slave cylinder and bearing
- New pilot bearing
- Changed transmission fluid - Mercon III ATF

I inspected the clutch/pressure plate and it was in good shape and looked like it might have had 10K - 20K miles on it. The last owner said it was recently replaced and it looked it. So, I put it back in. After I was done, I checked the movement at the slave/pressure plate and it is moving about 3/8" - 1/2" when the pedal is down. I was happy and thought this would solve the problem since the old pilot bearing seemed stiff and I saw the leak on the back of the master cylinder.

I drove it and all felt fine at first, but it was a cool day and I didn't drive it that long. When it was warmer over the next couple of days, it started getting hard to shift again. It's not been quite as bad as before, but still doesn't shift right. Any ideas?

 

Ford no longer licenses Mercon, it has been replaced by Mercon V on this TSB 06-14-4***MERCON ATF IS BEING REPLACED BY MERCON V ATF AS A SERVICE FLUID..
Could be a synchronizer wear problem I suppose, or maybe a fluid viscosity problem, seeing as how the fluid you used no longer has to meet Fords specs. If the system hydraulics have been properly bled/no air, aren't leaking down, is yielding the proper freeplay & travel, ect & if it was ok before the fluid was replaced, then maybe look to changing to a Mercon V fluid at the proper level & see how it goes.

 

This didn't start after I changed the fluid, it was already doing it and is why I pulled it apart. The fluid I used supposedly meets the Mercon III spec, which is why I used it. Isn't Mercon V a synthetic? I didn't know I could use it. I'll try that before I tear into again. I'll change it today.

 

There is no such thing as Mercon lll. There was Dexron lll, a GM specified fluid, similar to the old Mercon specification, so maybe your confusing the two???
There used to be a Mercon specified by Ford, which they no longer license & now is replaced by semi-synthetic Mercon V. Mercon V has a better base stock, so should perform better, maintain its viscosity & ad pack better over temperature & time & since Ford still licenses Mercon V, it has to meet their specifications for viscosity vs temperature, if that's the problem.
Unlicensed fluid isn't checked/certified by Ford to a specification, so we have to depend on the honesty of the blender & marketer, that it meets Fords old Mercon spec.
All that said, if as you've posted, it was doing it before you changed the fluid, & changing to Mercon V fluid doesn't fix things, maybe consider putting worn syncro's on your suspect list. Let us know how it goes.

 

Stupid me. That's exactly what I'm doing, mixing them up - sorry. Back when mercon V first came out, I remember Ford saying not to use it in place of Mercon. LOL. I'll try it and see what happens. I drove it again yesterday and it sure does feel like the clutch isn't completely disengaging. How much movement should I see at the slave?

 

Well my manual doesn't put a number figure on the release/throw-out bearing travel, just says observe it for "substantial" travel when the clutch pedal is fully depressed.
It does say to check shifting with the clutch pedal Raised 1/2 inch from the floor, wait a few seconds for things to spin down & with the vehicle at idle, you should be able to shift from 1st to R or any other gear without difficulty or grinding. To me that suggests slave cyl movement should be Greater than 1/2 inch.
You could put a 1/2 inch piece of wood on the floor where the clutch pedal makes contact, so you know your at the right height & its easy to hold/maintain the correct height, then with it at idle try shifting & see how it goes.
If you have trouble shifting, or it grinds, remove the release/throw-out bearing rubber inspection plug & have a helper fully depress the clutch pedal while you look through the inspection port to see if the slave cyl is moving the throw-out bearing more than 1/2 inch & how long it takes for things to spin down, or if they aren't spinning down because the clutch isn't fully releasing. If it isn't fully releasing, check the clutch master cyl fluid level, & or bleed the system, in case it has air in it. Or maybe the clutch master, or slave cyl are leaking/bypassing fluid, in which case you would observe creep/movement in the release bearing or slave cyl rod, when the clutch pedal is depressed & held in place.
If no joy, inspect the clutch pedal linkage & bearings, to make sure they don't have excessive play, such that when the pedal is depressed you aren't getting a full throw/travel.
If no joy there, suspect a worn throw out bearing or clutch plate finger problems.
If movement is ok maybe suspect worn tranny syncro rings, or the wrong fluid in the tranny, or wrong fluid viscosity.
A bunch more thoughts for consideration, let us know what you find.

 

All of that is new except for clutch itself, which is recent (see my first post). I visually inspected the pressure plate and all looked good. If the travel is supposed to be over 1/2", that's my problem. I'm getting around 3/8" -7/16" of travel. I'll try more tests, probably on Thursday when I'm off work. Thanks for the help, it's giving me some direction.

 

I agree 3/8-7/16 doesn't sound like its enough movement to declutch completely. Let us know what you find.

 

If your measuring the 3/8-7/16 at the pressure plate, I think that's about spec. Here is a link to some good basic info. http://www.aa1car.com/library/2003/bf100372.htm

 

I changed the fluid to Mercon V, it didn't help. The problem only happens after it has warmed up and that is what confuses me. I would think that the clutch travel would be a problem all the time. However, I measured the travel when cold and when hot. When hot, the travel is slightly less than when cold - maybe 1/8". I pulled the master and line out again to make sure there are no air bubbles. It seems to be completely bled. I'll put it back in and check the travel again when cold and when hot.

If this doesn't work, I'm not sure exactly what to do next except put a new clutch/pressure plate in it. I think I've narrowed the problem down to less movement when warm, but what is causing that? The pressure plate?

 

Ok that's good feedback. So now your sure you have the right viscosity & service grade tranny fluid in there, but noticed no change, so that eliminates the fluid viscosity question.
So, your sorta left with the normal lowering of tranny fluid viscosity after it warms up & if that means the syncros are worn, & or why the de-clutch dim. changes so much between cold & warm. I'm thinking maybe the master or slave pistons are weeping/bypassing warm fluid. Have you tested for Warm de-clutch dimm creep???
The other thing is that these systems are known to be difficult to bleed air from, so maybe in spite of all the checks, there is still some air trapped. Have you performed a bench bleed on the clutch master cyl, or a vacuum, or gravity bleed procedure on the master & slave cyls????

 

The master and slave are both new, but it was doing the same thing with the old master and slave. I haven't tested for creep, the fact that it was less when warm sounded like a problem by itself.

I bench bled the new master out of the truck, gravity bled the system, and used my vacuum pump on it. Right now, the master is out for the second time for a second bench bleed session just in case.

 

I finally fixed this. I had done all of the recommended tips and tricks that I had read on the forums and other places on the internet. I was convinced it was in the hydraulics, so after bench bleeding the new master twice, gravity bleeding, and using a vacuum pump, here is what finally fixed it.

I installed the master after the second bench bleed and hooked up the line at the slave BEFORE installing the master into the firewall. This allowed the master to stay facing in the right direction in case any air was introduced. Then, I installed the master, but still wasn't happy with the results. So I gravity bled, A LOT. I went through reservoir after reservoir of fluid, then I kept adding. It had always been a "fast drip" at the bleeder. After what felt like a gallon of fluid and an hour of slow pours, it turned into a stream and I knew I was onto something. It's fixed!

I've never bled a hydraulic system this stubborn.