Napoleon1991

I was wondering what the torque spec is for the balancer to crankshaft bolt on a 403. I have been doing a little research and I have found numbers anywhere from 60-310 ft lbs.

Fun71

I thought it was 120 minimum. Never heard as low as 60. I usually crank it as tightly as I can with my breaker bar.

Smitty275

As tight as you can get it. Its a 3/4" bolt and the 310ft/lbs is what it "should" have. Put an 18" breaker bar on it and give it everything you've got. You'll be fine.

Napoleon1991

Thanks for the replies. I have also heard that you should loctite the bolt. Is that true?

MDchanic

The CSM says "160 min." That leaves plenty of room to go up.

Well into the 200s is good, and if Smitty says you can take it to 310, then do that, but watch out for the other things that will fail at that point - whatever you've got holding the flywheel still, or causing the engine stand to fall over. I find I need a second guy on the other end of the engine, holding a pipe on the lever that rotates the engine stand fitting.

I suspect that "all you've got" on an 18" breaker bar will just get you to the minimum unless you are a gorilla.

Some people do LocTite them, but if you've got enough torque on it, it's really not necessary.

- Eric

Fun71

If you can stand on the breaker bar, then it's fairly easy to get above the minimum range. 150 pound person on the end of an 18" breaker bar = 225 Ft-Lbs torque.

I mention this only because the last time I needed to torque that bolt the engine was in the car and it was really simple for me to stand on the breaker bar.

MDchanic

Fair enough, but if it's on a stand, you can't stand on it, and, in fact, can't use all your strength in one direction because you have to be careful not to turn the stand over, or to turn it around in a circle on the floor.

I recommend a really solid pull on a 24 - 30" bar, rather than a hellacious pull on an 18" bar.

- Eric

Octania

Some very early 425 cranks actually had a 1/2" balancer bolt, which might merit a spec as low as 60 ft lbs. These are very rare and should not be used.

MDchanic

That's why the '65, '66, and '67 CSMs has a spec. of 50 ft/lbs for this bolt (for all V8s).

Those who follow that guideline live to regret it.

- Eric

Smitty275

And why should thoses cranks not be used? The torque of the bolt has to do with the bolt size and its ability to stay tight. Just because the crank had a half inch bolt does not mean you should not use it. It just means it has to be torqued according to its size and that happens to be 130 ft/lbs. for the 1/2 bolt.