'88 Tow Truck Clutch issues

[Designo614]

OK, Just got the truck, 454 SM465 tranny. Will not shift, shifter seems locked in place. I've done 2 things: 1, drained and replaced tranny gear oil with Sta-Lube 85W90 GL-4 gear oil; 2, replaced and bled clutch master cylinder and slave cylinder.

Suspected MC / SC thinking it's defective and not allowing clutch to fully disengage. When removed, I found the MC pushrod had broken off and the sharp end had destroyed that end of the MC, and the flex portion of the line between MC and SC was badly torn in 2 spots; so no wasted effort in replacing those. Once bled, I get about 15/16" of an inch travel at the SC.

First, what kind of travel distance there is expected to fully disengage clutch?

Second, since I can start the engine with the clutch fully pushed in, without the truck lurching forward, that tells me the clutch IS disengaged. So now do I have an issue completely within the shifter/tranny? Because it still won't move freely.

Anything else I can try before determining the tranny has to come out for a professional to rebuild/inspect?

 

[Customblue]

Remove the top of the transmission, the shifter housing. Make sure all the shifter forks are in "neutral" postions

 

[Designo614]

Remove the top of the transmission, the shifter housing. Make sure all the shifter forks are in "neutral" postions

So, I can't remove the entire top of it in the truck, can only see inside the shifter hole when I remove shifter. they are not lined up, but can I move them through the hole?

 

[Turbo4whl]

So, I can't remove the entire top of it in the truck, can only see inside the shifter hole when I remove shifter. they are not lined up, but can I move them through the hole?

Yes, they can be moved with the shifter out. Line them all up in the center. Remember the shifter is long with a mechanical advantage. You may not be able to move them with your fingers. If needed, use a small pry bar and a block of wood as a fulcrum.

 

[Customblue]

Turbo4whl is spot on

 

[Designo614]

OK. Had some time to get back in it tonight. Was able to align the forks and get the shifter back in, can find the gears in each position. Test drive, still doesn't want to shift once up to speed.

So, my regular mechanic actually still uses his squarebody tow truck at his shop (same tranny), and he mentioned that if the PTO is engaged then it'll be difficult if not impossible to shift, i.e. this exact problem. After getting the shifter back in and testing, I discovered that my PTO seems to be engaged no matter what the cable position. I have a plunger type cable operator in the floor, pull it up to engage PTO; except all the rear hydraulics, winch, boom and wheel-lift, work in either position.

The cable does move and does operate the lever on the PTO, so I'm stumped again...

 

[fast 99]

Yes, if the PTO is engaged the tranny can't be shifted. Can the cover be removed? I have worked on a lot of them, PTOs are pretty basic. If it won't disengage the problem should be obvious.