Well, the shifting on my '88 7.3 IDI has never been perfect, but I think I'm finally approaching the time to replace the clutch.

The facts:

Slave and master cylinders replaced 5 months ago
Awful grinding noise when trying to shift into reverse
Occasional grinding when shifting from 1st-2nd
Hard to shift into 1st from a stop
"Clunking" into gear while moving

I'm hoping this is a simple matter of putting a new clutch kit in it. My only other question is, should I get the flywheel resurfaced while it's out? My local clutch shop wants $100 to do it, so it's not exactly a huge financial investment, but it does provide a logistical problem because my "local" clutch shop is over 100 miles away and getting the flywheel there without an operable vehicle is an as-yet unsolved problem.

The clutch isn't slipping, so that leads me to believe that there shouldn't be any burned spots on the flywheel, which should mean that it's still in reasonable condition, right? Can I get away with not resurfacing it? Or am I just shooting myself in the foot?

 

check the bushing on the clutch pedal where the pushrod for the slave cylinder connects. if it is worn or missing, this will make the clutch not completely disengage.
which is what it sounds like your problem is. unless your throwout bearing fork is broken.
when a clutch goes bad it will slip, not stay partially engaged.

 

Thanks Tom, I'll take a look at that bushing.

If the throwout bearing fork was broken, wouldn't that introduce some more severe problems than what I'm experiencing?

 

not at the onset.
it will start as being hard to get into gear, and then as it gets worse it will just flat out not go into gear at all.

 

Well... Hopefully it's the bushing at the pedal arm. I'll have to crawl under and look here in a bit. That certainly would be an easier fix than a clutch kit or broken fork.

How much of a pain in the *** is it to replace the throwout bearing fork, if it were broken?

 

Well, I tried. But looking up underneath the dash, I don't see any possible way to even lay eyes on the top of the pedal arm, let alone do any work on it. What am I missing?

Also, while I was looking, it dawned on me that if the clutch weren't disengaging all the way, wouldn't that also mean that it would try to crawl forward when I'm sitting still, in gear with the clutch pedal in? Because it doesn't do that.

 

you are in good hands with tom, but til he gets back i will say that you should be able to see the location of the bushing in question ... you will need to lay on your back and look up and over towards the gas pedal side ... up where the swing arm on the end of the clutch pedal shaft joins clutch master cylinder pushrod. this a problem area when these truck gets old. is your clutch pedal fully returning ? if not, that is a tell-tale sign that the plastic bushing might be completely gone, and, even worse, the metal on the swing arm could be ovalled out. at any rate, well worth a look.

 

Thanks for the info Joey, I was trying to look directly at the top of the clutch pedal arm. I didn't realize that the slave cylinder pushrod was near the throttle pedal.

Yes, the clutch pedal itself functions normally.

 

Have you checked the fluid level in the clutch master cylinder?

 

I haven't. It was just replaced though, so I have no reason to believe that it wouldn't be functioning properly. And it had this problem before the MC and SC were replaced.

 

with my advancing age, petite 270lb figure, and crippled legs it is almost impossible for me to get under the dash to look up and do anything.
so i cheat and remove the lower dash covers so i can look into the dash instead of up under it.
clutch can still be slightly engaged and the truck will not creep forward, but it will make it hell to get into gear without grinding.

 

Don't these trucks (especially with the ZF5?) have an issue with the firewall cracking/bending around the clutch master? Might be worth investigating that, too.

 

yes they did Ian. i forgot all about that.
have your helper step on the clutch while you watch the clutch master cylinder. if it moves, you will need to reinforce the firewall

 

The firewall was inspected and reinforced when the MC and SC were replaced last summer.

Thanks for the tip on the dash cover, I'll poke around and see what I can find. Will it be obvious if that bushing is worn, or is it kind of a trick?

 

justa FYI. all the symptoms you listed have Nothing to do with a worn clutch

Slave and master cylinders replaced 5 months ago
Awful grinding noise when trying to shift into reverse(worn bearings, syncros or not enough disengagement)
Occasional grinding when shifting from 1st-2nd(bad syncros)
Hard to shift into 1st from a stop(not enough disengagement)
"Clunking" into gear while moving