The GMC CCKW

My truck rested for a year or so. Now I tried to start the engine but the starter was to weak to turn it over. A friend towed the truck and I tried to revolve the engine by slowly engaging the clutch while being towed. No effect. The rear wheels blocked.
Now my question. Is it possible to move the flywheel manually to free the pistons? Do I have to remove a cover or something to be able to reach the flywheel? I already removed the spark plugs and filled some oil inside the engine to lubricate the pistons. I don't have a crank lever to try it this way btw and I can not disassemble the engine where the truck is. So these last two options are not possible for me.

Regards,

Chris

You can either remove the lower dust shield, or you can just remove the starter and access the fly wheel there. While you have the starter off, you might have it checked. You can also use a 12 volt battery to start, as long as you don't engage the starter too long.

A friend of mine spliced his heater hoses into a good truck and ran it. The heat helped the stuck block expand and it worked!

Be careful: I have a 270 with 1500 miles on it. They towed the truck and dumped the clutch. It broke the BELLHOUSING! and ultimately broke the front shaft on the transmission

Thank you guys. I will try a 12V battery first. Might be the easiest solution. Heating up the engine is also a good idea.

Regards,

Chris

The FIRST thing I would recommend is verifying that the engine can be rotated, and isn't locked up. If it is locked up and you put 12 volts to the starter, you run the risk of tearing something up...

Go gently. Remove the lower dust shield and using a pry bar or large screwdriver lever off the bell housing onto the teeth of the ring gear. It doesn't matter which direction you try first. Alternate directions, you will feel the slightest movement if there is any there.
If the crankshaft rotates so far and stops then you go in the opposite direction and it stops, that means a stuck valve. If you force the issue you may strip the timing gear or bend a push rod. This is quite possible if you just whack the starter with 12 volts. Go easy.

David

Mission accomplished!

I followed David's and Retro-Roco's method and was able to move the flywheel by using some force with a pry bar. Now the engine rotates again.
Thank you guys.

Regards,

Chris