Using this tool I rented at AutoZone. As far as I can tell, I'm using it correctly but something's not right because when I try to start pressing on the damper using the bearing, nut and 'jack screw' (the large threaded rod for the nut and bearing to press on) the jack screw just turns. For this tool to work, the jack screw would have to lock tight, and the nut and bearing would then be able to press on. But it's not doing that.

What am I doing wrong? There's nothing else in the kit that I'm not using. Something's not right...

You have to hold the screw with something while you tighten the nut. If it doesn't have a head you can put a wrench on see if it has a female allen or square in the end that you can use a ratchet / breaker bar on.

If the screw is long enough, you can put two nuts on the end furthest away from the engine, tighten them against each other, and use that as your holding point. It's 3/4-16 thread.

If you don't want to buy nuts... the other choice is first let the screw bottom out in the crank so it won't turn anymore. Then you have to immobilize the crank somehow. You can put two longer screws in the pulley bolt holes in the balancer and stick a bar between them. Or if the engine is out you can do the same at the crank flange on the other end.

Thanks Pierre. You must have been sending me brainwaves: it's on already. Was wondering how I could hold it and crank down on it at the same time, but the damper slid on pretty easy actually, once I did it right.

Welcome.

I hate those cheapie tools. They work, most of the time. I munged a bearing on one once. I bought one of these, which is the summit branded version made by these folks. It's the bees knees. Made in USA too to boot. There are cheaper knockoff versions too. Once you use one you won't go back.