[75gmck25]

I'm trying to break loose the crankshaft bolt on my 350 and all I end up doing is turning the engine over. I have a TH350 automatic, so I can't use the transmission to hold the crank in place. The three outer bolts came out without any problem, but the large one in the center won't break loose.

This Goodwrench engine only has about 12k miles on it, and I don't think the crankshaft bolt is unusually tight. I don't remember what I torqued it too when I installed the accessories, but I probably used the recommended torque from my repair manual.

I tried using the drive belts to hold the pulley while I loosened the bolt, but couldn't get enough leverage. I also tried to figure out a way to use the three outer bolt holes in the pulley to hold it while I loosened the large bolt, but the deep dish of the accessory pulley gets in the way.

Any simple suggestions for breaking the bolt loose? I'd rather not rent an impact wrench just to break one bolt loose.

Thanks,

Bruce

[WakBordr7387]

Have you tried the poor boys impact method?
Pretty much just get a breakover bar with the right socket on it, and instead of pushing/pulling on it to get it to go. Start hitting on the breaker bar with your hand or a hammer.
Usually this will jar a bolt loose and make it easier, plus its usually the steady force that will twist a bolt off to.



Brad

[elliott]

I'm not sure if this is the "right way", but I just clamped some vice grips to the flexplate and let it catch on the bellhousing.

[jimfulco]

Use a socket and a long breaker bar or cheater pipe. Put the socket on the bolt head, push the breaker bar over until it's resting on the top of the left frame rail, and bump the starter. It should loosen up so you can turn it OK.

Might be a good idea to put some plywood or something between the radiator and the breaker bar in case Mr. Murphy tries to sneak up on you.

[lust4speed]

Starter method used above is excellent - works so easy you wonder why it isn't in the Chilton Manual. Do ground out the coil so the engine can't start.

[75gmck25]

Sounds like a good idea, but I do worry about putting the ratchet through the radiator if everything slips the wrong way.

Would I ground out the coil, or just pull the power lead to the HEI? On a Ford its fairly easy to put a remote starter on the solenoid and bump it over with the ignition off, but on my Chevy ('75 vintage) all the terminal connections are down on the starter.

Bruce

[BBCMudbogger]

Or how about an impact?

[lust4speed]

Impact works excellent also, but if you don't have an impact then this is the next best thing. Pulling the power source to the ignition would be good, but either will work. Also make sure that you overlap the frame by a good margin by possibly using a short length of pipe or something on the ratchet. Bump the engine before to make sure that you will be positioning the handle properly, then make sure the person bumping the starter just uses little hits. As soon as it breaks loose then just back the bolt out normally. I also like to lay the ratchet on top of the frame rail where the pressure goes down because if it does slip off there's no chance of it hitting anything. Once you try this you'll see just how easy it works.

Also, I know that Chevy and Pontiac will loosen the bolt when the starter is bumped, not familar which way other brands spin - so other brands just need to check the rotation before hooking up the socket.

[75gmck25]

I finally took off the flywheel cover and clamped vice grips on the edge of the flexplate. My son broke the bolt loose while I held the vice grips braced up against the edge of the transmission case, and it worked without a problem.

Thanks for the help.

Bruce

[05mudder]

If the motor and/or the oil pan is removed you can put a piece of plywood inbetween the conecting rods and the block and loosen the bolt that way.

[sam-missle]

Originally Posted by jimfulco

Use a socket and a long breaker bar or cheater pipe. Put the socket on the bolt head, push the breaker bar over until it's resting on the top of the left frame rail, and bump the starter. It should loosen up so you can turn it OK.

Might be a good idea to put some plywood or something between the radiator and the breaker bar in case Mr. Murphy tries to sneak up on you.

i used to do that a lot years ago, one day i did it on a toyota land cruiser, blipped the starter and heard a thud, there went the balancer and crank snout rolling across the shop.

[bondo]

Ayuh,.....

Just for the sake of furture readers,....

Slipping a lenght of Rope into a Sparkplug Hole to bind the Piston against the head Works Great too......