Undoing crank pulley bolt?

It finally happened to me, crank pulley fell apart, and I came home on the back of an AA van.
(What a stupid design, it is obviously going to fail, as the fan belt tension acts to flip the pulley off the spindle.)

I got a new pulley (sorry Martin, I need to fix it right now this minute)

But I can't undo the crank bolt.

I made this








and I've got a 4 foot long bar on the socket, but all that happens is the bar is bending.

I have a windy gun that is supposed to do 235ftlb, but that doesn't make any effort to undo it, but I suspect that is because I have 2 extension hoses and it isn't getting enough air.

I've sprayed round the flange on the bolt with GT-85

All that is left is to wait until I can get a mate round, bend the 4 foot bar double and hold the strain on, and get him to whack the socket end.



Any suggestions from all you folks who have managed to undo it?

I suspect the old using the starter and let the spanner flail round to hit the chassis dodge isn't going to work on this one....

I used my battery impact gun with a fully charged battery. First press and bingo. The starter motor trick is good as long as the driven arm only moves 90 degrees. Its best if somebody keeps a push on the socket to the bolt head while the switch is operated for the second it takes to engage the motor. Obvious safety awareness required!.

Cheers, I was hoping someone would have a little tip.

I wonder if it has been done before and some idiot has put loctite on the threads when assembling?
It is only supposed to be 108 ftlb, I must have got over 400 on the end of that bar, I'm frightened I will shear the head off, split the socket or shear off the square drive.

The only way to shift that is to stick weld to the bolt head, and hope the bolt gets enough heat down its length to melt it.

But then I'll never get the socket on after.........

I can get the blowlamp to the bolt head, but most of the heat will just go into the pulley,

Stuck now until I can get someone round to help on Saturday.


A replacement engine would have been less trouble, and probably only twice the cost of the pulley

I've had no problem with a 3ft breaker bar, even with the engines out of the car, rolling about on a trailer floor. If your bar is bending, get a stronger bar!

Have you tried the socket long bar and flicking the starter?

j999pre wrote: Have you tried the socket long bar and flicking the starter?

No, I need someone to operate the starter while I watch what happens/ keep the socket on, but how tight this is it will probably twist the crank before it goes.
"
Busta, I do have a 3/4 drive bar, and a reducer to 1/2" somewhere, I don't have a 17mm 3/4 drive socket though. I've got a 2' Draper cracker bar and 3' of thick walled tubing, but the cracker bar bows like a banana unless I slide the tube right down.

It must be loctited.

I can try the blowlamp on the head on Saturday, other than that I will have to slip the radiator in and drive it nearer my compressor to use a shorter pipe and let the windy gun hammer away for a while and hope it eventually breaks free.

If the head shears off and leaves the thread stuck or loctited in the crank I will really be in trouble.

(I'm in trouble now as I can't use it anyway with no waterpump drive)

facade wrote: It must be loctited. I can try the blowlamp on the head on Saturday, )

What a nightmare. I think I would have tried the heat by now and defo an impact wrench.

If you end up going down the welder route, Get a nut large enough to fit over the bolt head and weld on, then you still have the new welded on nut to get a socket on. Similar to the photo.

Mine was corroded in and took some shifting, 2ft breaker bar plus a lump hammer. The impact force goes a long way to help getting it undone.

Can't move it!

It isn't a left hand thread is it?

Got mate pulling with all his weight on the 4 foot bar, I thought the engine mountings would rip apart, and then belted the bar close to the socket with a lumphammer. Not the slightest movement. (Apart from I now have a permanent bend in the bar)

Warmed the bolt until it glows red, and the rubber on the pulley smokes, and tried again, nothing. (probably wrecked the oilseal now)


Looks like a major operation now, make a drill guide and centre drill the head off, then if the thread is seized drill that out and clean the threads up. Bumper off to do that though.

Last chance is next door's son in law is a breakdown mechanic, and probably has a powerful electric impact gun, he comes round to see them tomorrow.

facade wrote: Can't move it! Warmed the bolt until it glows red,

I wouldn't have heated it that much - unless it pigged me off.