The Stovebolt Site Forums The Shop Area Engine Shop How to See if Engine is Locked Up?

An advisee told me that if I can turn the fan, the motor was not locked up...TRUE OR FALSE??

If FALSE what should I look to turn to make sure??

IF it won't turn...then what? I've restored tractors in the past, but piddlin' my way through trucks now....a lot of the same setup as my old tractors but any advice is Appreciated Greatly!

53 GMC

turning the fan just turns the water pump, unless you can hold the belt tight enough to turn the bottom pulley attached to the end of the crank - only possible with all the plugs out, and maybe not then .... you need to either drop the splash pan below the clutch or pull the starter, and use the teeth on the flywheel with a pry bar to really check if it's siezed or not

if it appears siezed, it may be possible to free it up, just depends on why it's stuck, but you could start with some thin lube in the plug holes, like penetrant or diesel, soak it good for a couple days and try again

Bill

If the truck will roll, put it in high gear, and roll the vehicle back and forth. If the crankshaft turns, the engine isn't locked up. If the wheels slide, DO NOT go to the next logical step and try to tow it, or get it rolling and pop the clutch! That's a good way to bend rods, or break an axle or a driveshaft, or maybe trash a transmission.
Jerry

My old 216 was locked up tight and I tried everything that was mentioned above with no luck. When I finally pulled the head one piston was the culprit (number 3) the others looked like new. Since it had a cracked block I salvaged what parts I could but could not get it free until I banged it hard with a hammer and a wood block. Moral of the story you never know what you may find in a 60 year old engine/truck.

I would squirt something like Marvel Mystery Oil in each cylinder and let it set a week or 2 before I did anything. Then remove the tin cover from the bottom of the flywheel housing and try to move the engine with a pry bar. If the engine is totally free, you can put on a pair of gloves and turn it by hand.

Thank you red 58, HOTROD Lincoln, Brad Allen, and Crenwelge for your help. I will use yalls advice! Ill squirt some Marvel Mystery oil or some diesel in there to try and make sure all is loosened up when i get back home one day....

Thanks again!
53 GMC

Do our trucks not have a crankshaft nose bolt?? Couldn't you simply get a ratchet on there and turn it over? I know there were big changes between 53 & 54.

53 GMC, Make sure that when you try to turn the engine over, have an assistant push in the clutch pedal or hold it down with a 2x4 or something because if your truck is stuck in gear it will be awfully hard to turn the whole thing with your hands. I also posted in your transmission thread about how I got my truck's engine and transmission unlocked.

Thank you jdl! that will be really helpful...I can get my younger sister to sit in the seat and hold the clutch in while i strain! haha Thank you for your help!

No problem, it's the least I can do after all of the help I've gotten from here. Just passin' on the knowledge.