Hello all: a friend needs a pulley from one of my D4 parts engines. I’ve never pulled one off the crankshaft before; can anyone offer me some pointers? I don’t want to break it.
I’ll look at the parts book later if I am able. TIA, JM.

You won’t break it if you use the correct puller that bolts to it.

You cannot pull one using a jaw type puller that grips the outer rim. The one I pulled from a D318 was really stuck on there. In fact every Caterpillar crankshaft pulley I have ever pulled was really hard to get off. I ended up tightening my home made puller up as tight as I could get it and then smacking the end of the forcing screw with a light sledge hammer before I got it to pop loose from the tapered nose of the crankshaft.

Note, small lock bolt (3/4” head size??) in the center of the big retaining bolt is LEFT HAND thread. I couldn’t remember for sure which of the two was, so I looked it up in the serviceman’s reference book.

The large bolt takes a 2 3/4" six point socket and is right hand thread.

"Rome wrote:

The large bolt takes a 2 3/4" six point socket and is right hand thread.

You can take a piece of flat bar with a slight bend in it and put a hole in it for the left handed threaded bolt. put the left handed threaded bolt back in LOOSELY to hold the flat bar and help break the big bolt loose.

Thanks everyone. This helps a LOT. Should make my task a little bit easier. Hardest part is fishing the motor out of its resting place. Thanks again. JM

Don't screw up the left hand threads with your puller screw. Telling on myself (old age) I have the left hand tap if you need it.