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MG MGA - Front nut removal

My engine is on a stand and I'm trying to remove the front pulley nut from the crank. It won't budge with a 1/2" drive air impact tool driving a 1 5/16" socket. Being on a stand it is hard to put an Archimedes length breaker bar since the stand will move. I've tried tightening and loosening directions. The engine is stuck, not sure where yet, so the c/s does not rotate. Also the flywheel is off.
Any ideas out there ? Heat ?
A Pearse

I guess the trick I learned on this BBS won't work for you - Turn the engine over with the wrench or socket bar wedged against the alternator bracket.

With the engine seized, you don't have the problem of the crank turning either.

Can you wheel your engine stand into a corner where you might get some leverage with a breaker bar ?

If you try heat to loosen it up, be sure to wait for it to cool down before trying again, as the bolt will expand (and contract) faster than the crank.
Chuck Mosher

This thing is actually a bolt then, not a nut? It would seem then that what is stopping it undoing is the face of the bolt head is bonded to the pulley, rather than say, rusted threads. I will try more with the breaker bar and a heavyweight helper. What is the actual thread size?
Art
A Pearse

You have bent back the washer that locks one side of the bolt head up, correct?
Mark J Michalak

You could also try heating with a torch and quenching with water this will quite often beak any bond between dis-similar metals and rust bond also. I have also found that impact tends to quite often work better than supreme torque at times like this such as repeatedly striking the end of your breaker bar with a large plastic mallot. There are some mallots that have a good cast steel weight to them, but a plastic face.
Good luck
Ralph
Ralph

You might try another impact wrench. Some are light duty, and others are much stronger. I recently bought one that is way better than the one I was using. I have to keep it turned down to keep from breaking small bolts. Maybe you could borrow one from someone else, or try renting a stronger one.
Ed Bell

Get your breaker bar on it and apply as much torque as you can. While applying this torque have an assistant pour boiling water on the fastener. Sounds "hookey" but it was worked for me before. If it does not work, you have some hot water for some tea, and you can think of your next move.

Good Luck,
Mitch
Mitch Smith

It is a bolt threaded into the crankshaft, with a lock tab to keep it from turning.
Russ Carnes

I would try what Ralph suggests - the thickest breaker bar you can find (thicker means less bend so more of the effort goes into the turning effect)- and then whack it with the heaviest lump hammer you can get. I had this trouble with a midget way back - this worked eventually - the shcok breaks the binding seal. I will have the same job to do shortly as my timing cover seal is leaking - but with engine in situ. cheers Cam
Cam Cunningham

I just did mine this morning with the engine in the car. I used an impact socket and ½” breaker bar with a 4’ cheater on it. To keep the engine from turning I used the rope trick. Turn the engine to just before TDC and feed some rope into the first cylinder through the spark plug hole. This lets you really crank it and mine popped loose on the second pull. If you have the pan off you could also wedge a piece of wood in the crank. The threads are clean. The rust under the washer is what is holding it. I had used some penetrating oil and let it sit for a week and gave the bolt a few good raps with my hammer to "loosen it up."
Dave
David M Evans

Providing the tab washer is bent back the bolt will undoe with an impact wrench of sufficinct size and torqure. You need a large compressor and a 250 ft lb impact wrench and it should loosen.

andy
Andy Preston

Art, What I did was install a "C" clamp through the starter openg and clamp down on the fly wheel. Go to home depot and get a 4' pipe to fit the end of your rachet. A plumbers wrench works well if you think the bolt may be rounded.
WMR Bill

Bill, the flywheel is off; the resistance to turning is a seized engine.
I have now stabilized the front of the engine mount using a triangle of 2 x 4 lumber bolted to the front plate. Now I plan to use the 3ft breaker bar. Since the resistance is in one or more stuck pistons, is there any risk of me bending a con-rod? How hard do I dare bear down on this bolt?
A Pearse

An impact wrench is the least threatening to other engine components. I don't know how much pressure you can put on the front of the crank without bending something besides your breaker bar. I tried the long handle with a three foot cheater on my stuck engine. It was still in the car and I could put as much pressure on it as I liked. I quit trying for fear of damaging something internally, and ended up using an impact wrench when I had the front of the engine lifted enough to get at the bolt. I have a fairly good one, and it took full air pressure to break the bolt loose.
Ed Bell

You are not going to break anything using your bare hands and a bar - just think how much force that engine is producing when running and relate that to your own relative strength. Be careful if you have a diet that's heavy on spinach.
dominic clancy

Dominic is correct, you won't hurt it. Anything that breaks is already broken. there is a new product on the market, manufactured by Loctite, called 'Freeze and Release'. I have tried it with good success and it may help you.
mike parker

Just tried a 3 ft pipe on my 1/2" breaker bar. Twisted the 1/2" drive end right off! Must be cheap crappy tool - no name. Also tried 12" pipe wrench outside the socket + 2 lb sledge. No move. Next will be a 3 ft pipe wrench over the socket.
A Pearse

Art,

I recently removed a similar crank bolt from my wife's Honda. My 550 ft-lb. 1/2 impact wrench wouldn't touch it. Finally using a special tool to hold the crank from turning I was able to break the bolt free with a 4 ft. x 3/4" breaker bar, 3/4 to 1/2 impact reducer and 1/2" impact socket (Harbor Frieght). I used a 10 foot piece of 1" black pipe on the end of the breaker bar (the 6 foot piece I tried was not long enough). Also put a block of wood under the socket head to maximize leverage.

The bolt let go somewhere short of 90 degrees of rotation. It made a terrible "crack", but I had been forwarned that this was the bolt letting go rather than something breaking.

Here is an alternate method, one my grandfather used on Model A wheel nuts. That is a very old 18" Cresent wrench that was beaten with a 5 lb hammer to loosen the nuts.

Good luck!

John


jjb Backman

Well, it finally came loose with the 3 ft pipe wrench placed over the socket. Quite easily actually. Thanks to everyone for your encouragement and helpful hints.
Art
A Pearse

This thread was discussed between 03/10/2008 and 08/10/2008

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