I rebuilt the clutch in the truck last August. Recently it is getting harder to shift gears. There is an audible “click-click” sound typically and sometimes it just “slides” into first (similar to accidentally shifting without using the clutch). Pedal pressure seems normal.
When it is cold it runs relatively normal, but after running it for about an hour, it’s HARD to shift into any gear. Once or twice, I’ve had to shut it off, put it into gear, and then turn it back on.
Like beowulff, I’d suspect the slave and/or master cylinder. Maybe just bleeding it would fix the problem.
Also is there any adjustment for the clutch? If it’s not fully disengaging that will make shifting difficult.
Any throw-out bearing noise?
Have you checked the fluid level in the tranny? Is there a specified fluid change mileage for it and it’s overdue? I once put in a super slick oil into a manual transmission. It was the correct viscosity, but suppose to be ‘better’. I could barely shift the transmission afterwards. Evidently that transmission needed a little friction from the fluid to work properly.
Clutch hydraulic problems are the most common cause of this type of symptom, though not the only cause.
Carefully inspect the firewall around the clutch master cylinder. Sometimes the sheet metal cracks and flexes enough to prevent full disengagement. If this is seen, the cure is to repair the firewall and/or brace the master cylinder so there is no wasted motion – the cylinder shouldn’t budge – when the pedal is operated.
The next thing to check is the hydraulics. Start with the fluid level in the reservoir. If it has gone down from its normal level, that suggests a leak. Inspect the cylinders for leakage where their pushrods come out of the cylinder body. Peel back the rubber dust boot if necessary to check for wetness. The master cylinder can be observed from inside the cab where it comes through the firewall; the slave cylinder will probably have to be withdrawn from the bellhousing for inspection. If there is leakage, replace the cylinder(s) as necessary. (Some of these Ford systems are notoriously hard to bleed without special equipment, but I imagine there are internet sources with tips for doing this.) If there is no leakage, the cylinders are probably okay, but it is possible to have a weak cylinder that leaks internally. Usually, a hydraulic problem is indicated by the pedal not having normal resistance throughout its full stroke.
Sometimes the problem is with the clutch pressure plate or clutch disc. Some brands of parts work more reliably than others, and I would be especially distrustful of rebuilt rather than new components.
Another possibility is the pilot bearing. It’s the part that most plausibly would act up when hot. If it’s sticky or rough so as to not allow the transmission input shaft to rotate freely when the clutch is disengaged, that can certainly do it.
It can be difficult or impossible to evaluate a pressure plate, disc, or pilot bearing directly when everything is assembled. It’s generally necessary to be certain that the hydraulics are working properly and giving full motion to the release fork, and if so the process of elimination leads to removing the tranny to access and inspect the mechanical parts of the system.
My '95 F350 had the most Mickey Mouse pedal-to-pushrod attachment imaginable.
There was a plastic (yes, plastic) bushing that went into around the clutch pedal shaft, and then into the pushrod. This POS would wear out quickly. I finally made my own bearing out of brass tubing, lubricated with molyplate. It’s worked great ever since.
If Ford hasn’t fixed this in the intervening 8 years, it’s worth a look under the dash.
Not sure if they fixed it on the later trucks, but my '97 wore out the bushings on the cross shaft that carries the clutch pedal itself, as well as the crown shaped bushing that connects the pedal to the master cylinder rod. This resulted in a lot of lost motion leading to incomplete disengagement and hard shifting.
The bushings actually wore completely through, leaving the shaft running on the bracket. This wore a groove in the shaft and ovaled the hole in the bracket. I was unable to get the needed parts to replace these. So I bored out the bracket and brazed in a bushing to restore the hole to OEM size. The shaft I was able to turn 180 deg. so that the grooved side was not loaded. Lubed it up with high moly content grease. Seems to work fine five years later.
I didn’t want to weld or braze on the shaft because it also carries the brake pedal. The worn spot was at the outboard end where bending loads are minimal, so I am not too worried about the weakening and stress concentration from that, but didn’t want to compromise the temper with welding heat.
This is all hidden way up under the dash, and was kind of hard to get a good enough look at to see what was going on.
Update: I bled the clutch and the fluid was blacker than Satan’s soul. Also mixed in the fluid were chunks of what could only be blue shop towels (*smacks head. When I changed the clutch in August I did put a blue paper towel in the intake hole so I wouldn’t have to bleed the clutch. It must have gotten in).
So I refill with fluid and MUUUUUUCH better. Great shifting. But not perfect so I keep bleeding it. After bleeding, I can see the clutch full engage the slave cylinder, however since then I can’t get the shifting to not be so hard even though it’s full of fluid.
So my assumptions are:
Since it’s full of fluid, no leaks.
Since it worked when I didn’t screw with it, no bad parts.
I’ve got an airlock somewhere.
Any other possibilities? Any suggestions on bleeding this damn Ford? The only links I can find are for basic bleeding…Thanks again.
Buy or improvise a tool that will inject brake fluid into the clutch bleeder screw, and bleed the system “backwards,” pushing fluid (and air) up into the reservoir.
(Dedicatedtool by Phoenix; oil squirtcan that could be adapted – must be 100% free of oil.)
Use a handvacuumpump, sealed around the reservoir opening, to induce a partial vacuum above the fluid and coax the air into the reservoir.
Thanks everyone. I spent about 3 hours on Sunday following some tips online and tapping the clutch line while a friend pumped the clutch. After repeatedly bleeding and tapping until no more air bubbles came out, I think I can call this one a fix…
*Note to self: Don’t leave shop towels in internal vehicle parts.
