Can I run the engine for a short amount of time with a loose crankshaft pulley bolt?

Question

I have a 2001 Honda Prelude SH (Honda H22A4 engine). I am about to tackle replacing the timing belt and the cam/crank/balancer shaft seals on my own.

However, the one tool I don't have is a torque wrench (impact or otherwise) suitable for the 170 ft-lb torque spec on the crank pulley bolt when reinstalling it (I've got an electric impact driver with a 125 ft-lb spec, and a cheap torque wrench with an 80 ft-lb max). Also, I did order Honda's crank pulley bolt removal tool, although I suspect I'll have to take it to a shop to get help cracking the bolt anyways if I can't do it by hand.

My crank pulley has splines and a key, or something -- I don't know the terminology so here is a picture:

(image source)

The bolt just fits on the end of the crankshaft, nothing exotic (the special tool has a hole in the middle and sits in the large socket so you can hold the shaft still while cracking the bolt):

(image source)

So, my question, which I've probably hyped up too much, is simply this:

Assuming I have to drive (just a few blocks) to the shop to get help cracking the bolt and then drive it back to get help tightening it to 170 ft-lb when I'm done, this means I'll have to do this driving with the bolt tightened to a significantly lower torque. Can I do this? If so, should I take any special precautions? I don't have enough experience to predict whether or not the speed of the crankshaft will cause the bolt / pulley to slip off, or damage the splines or key, etc.

The crankshaft spins counter clock-wise and the bolt is not reverse-threaded so I do know that at least revving up will naturally tighten the bolt (but maybe revving down would loosen it?).

If I can't drive the car with a loose pulley bolt I'm not really sure what else I can do. I suppose I could rent a compressor and impact torque wrench. That'll make reinstalling the bolt no problem. I'm not looking forward to cracking it though.

Answer 1

tl dr: You possibly could, but why not just do it the right way?

Get the right tools for the job and do it right from the get go. This way you won't have to worry about anything falling off while driving down the road.

First, get the Honda hub socket which Lisle makes. You can get it (or a close facsimile) just about anywhere. It's Lisle PN: 77260 and looks something like this:

This tool will hold the crank in place while you get the crankshaft bolt out of the middle.

Next, to get the crank shaft bolt out, you'll need a breaker bar, with possibly a cheater pipe to get it to break free. In fact, you'll need two different breaker bars, one to use on the above tool, and one to go on the socket you'll need to break it free.

Next, get a torque wrench to tighten it all back up. There is almost no way to use an impact wrench to get a proper torque on a fastener ... there are torque sticks which are used to put lug nuts on, but those only go to a maximum of 100 lb-ft normally. Also, you don't use a torque wrench to take off fasteners, as you'll ruin your torque wrench (you'll kill the calibration on it).

All-in-all, use the right tool for the right job. Do it right the first time and you'll never regret it.

Answer 2

Crack it loose and then have them re-tighten to 70 lbs, this way you can remove it when you get home without risking it coming loose during the drive.

Answer 3

Well, you can ... so long as you don't have the same result as happened to a friend of mine.

He was driving along when there was a sudden "clunk" and the ignition warning light came on. The obvious guess was "broken alternator drive belt," so he pulled over and stopped to investigate.

Indeed, there was no drive belt to be seen. There was also no crankshaft pulley, which had somehow worked itself loose and fallen off. The "clunk" was presumably the sound of the pulley hitting the road. He went back to look for it, but never found it.