My 2003 B2300 has about 150,000 miles on it, and the 5-speed manual transmission seems to be getting very stubborn when shifting. I’ve never had the fluid in the transmission changed. When I suggested that he do so several thousand miles ago, the mechanic I’ve been using seemed to think that was unnecessary. Though it seems to drive fine when in gear, there is more resistance getting the shift lever to slip in and out of virtually all of the gears which is very annoying. I’m wondering if the difficulty I’m sensing might be resolved or improve with a fluid change, or if maybe the clutch might need a cable adjustment to ensure the clutch is disengaging fully? [Edit: apparently the truck has a hydraulic linkage which might need service/bleeding]. I’ve never had the clutch or transmission serviced. The truck still runs great otherwise.

Any advice/guidance on the matter would be much appreciated. Thanks in advance.

 

Your transmission is probably due for fresh lubricant, but I doubt this is causing the shifting problem. Is the level close to where it should be? If so, I have even more doubt that the fluid is the problem. It won't hurt to change the fluid and see if that helps.

Is it noticeably easier to shift from one gear to another with the engine off, clutch in and the truck stationary? I suspect your clutch is not releasing from the flywheel completely and this is what's causing the difficult gear changes when the engine is running. With the engine running, the tranny in 1st and the clutch petal on the floor, does the truck want to creep forward if you don't have a foot on the brake petal?

Others have written posts talking about having to bleed their clutch hydraulics, especially if their truck has an aftermarket slave cylinder. I don't know how air could get in there if the reservoir hasn't drained down to empty, but it seems to be a thing. So yes, try flushing your old fluid (it's brake fluid) out through the slave cylinder and replacing it with fresh fluid. You won't be able to flush out everything in the slave cylinder and if there's air in the master cylinder you have to use the bench bleeding process to get it into the line and push it out through the slave cyclinder. I don't know if you can bench bleed the master without attaching it to a slave because the line has a check valve where it goes into the slave cylinder.

 

Thanks for responding. The hydraulic line is the original factory unit. There is no tendency for the truck to "creep" from a stop with the clutch pedal depressed when it's in first, so I assume that the clutch is fully, or close to fully disengaging when the pedal is down. The lever is easier to move through all the gears with the engine off and clutch pedal down. Does that suggest a clutch issue? I found a 13 year-old instructional video about bleeding the hydraulic line, and doing the procedure as described requires removing it from the truck, something I'm not prepared to do myself, especially without a lift:


I'm not even inclined to check the fluid level in the transmission myself, I'm too old and my shoulders are too creaky to even get under there to do that comfortably. But, at least I'll be informed if I can find a reliable mechanic with a lift to look into the issue. Thanks again for your advice!

 

That's a good video because he explains both diagnosing whether the hydraulic system is working correctly and how to bleed the master and line from the top. I think I did it through the slave cylinder because I wanted to flush out all of the 33 years-old fluid in my slave cylinder (it was black).
Sounds like you won't be able to work on this yourself, but for the sake of sharing info and helping others, note that you probably don't have a line attachment to the slave cylinder like he showed in that video (with the clip). Here's two videos that show how you can release the one Ford used without buying any special tools. I use small screw drivers but I avoid pressing the white plastic with a driver tip until it's all the way into the fitting on the slave cylinder. Mine did not have any sort of lip on the white plastic, probably an older design.

(start at about 2:45)

 

Found two new videos that show a way to bleed the lines without disassembly using sucttion:

 

I'm skeptical that would work if the air is in the slave cylinder but it won't hurt anything besides your wallet to try it. I also doubt you can make enough vacuum with your mouth. Is that kid nuts or is he pulling our leg? Too bad you don't have someone to open and close the slave cylinder bleed screw while you refill the reservoir. It appears the vacuum can be used to clear the line and master cylinder.

 

I guess with the long clear tube he can see the fluid and avoid getting it in his mouth? Judging by the comments in these two videos, these methods work. If so, it sure would be a lot easier than using the method that requires removing the master and line from the truck.

 

Any updates on your shifting issue?

 

No. The truck is driveable with the stubborn shifting, so I'm just dealing with it. I suspect the clutch plate is coming to the end of its life and needs replacing.