M936 Boom Removal

[Falcon]

Trying to remove crane boom, have every thing off except for the main pivot pin at rear. Anyone know the secret to getting the pin out? Hopefully with out damaging it.

 

[Mullaney]

Trying to remove crane boom, have every thing off except for the main pivot pin at rear. Anyone know the secret to getting the pin out? Hopefully with out damaging it.

Hi Falcon,

So - removing the boom pin. Are you talking about the pin in the pictures below?



Guessing you already have it supported on both ends with sling of some sort? It should be as simple as driving it out with a brass punch. On the other hand - if the truck wasn't regularly greased there - there will be a "ridge" where the boom raised and lowered. Over time it digs a trough and you just can't get it aligned right to hammer the pin out. If you swat it with an 8 or 12 pound sledge and it doesn't move that may be your problem.

Depending on what you have to work with... Hopefully a pair of chain-falls (one on each side of the boom) supported by a gantry where you can raise in tiny increments you might be able to find that sweet spot.

Not on a 936, but other booms I have worked on: The pin was so worn that it was sawed between the "boss" and the "turret" with an air hacksaw. First time I did that, I was sure if I got one side free I could pound it out. Didn't happen. Ended up sawing it into 3 pieces, lifted the boom away and the pin tapped right out. Layed it on a steel table and there was about 3/16" wear on the hardened pin. Naturally the bushings were shot and also had to be replaced...

If I didn't hit the topic, let me know and I will share all I can.

 

[A Seabee]

Worked at a shop where we did a lot of boom overhauls. We rigged a jackhammer to a skid that had forklift holes. We’d raise it up to the work and drive the pins out with that set up. Just had to be careful not to mushroom the end of the pin f it’s not tapered. It’s also possible to get off kilter and gouge the pin bosses. soak it down with Kroil, and get a drift holder have your helper wear a face shield (you too) and hold the drift while you hammer away with the sledge. Finding the sweet spot as described above is also critical in getting them apart. And yes, if all else fails, saw it off. Good luck.

 

[Csm Davis]

Trying to remove crane boom, have every thing off except for the main pivot pin at rear. Anyone know the secret to getting the pin out? Hopefully with out damaging it.

Did you get it done? Anyone else done this? Wondering if it was major pain or if I should just disassemble the boom in place for repair?

 

[charlesmann]

I rmvd the boom on the spare 936. I had to beat the hell out of the pin and deformed the grease fitting hole. it had not been greased regularly and the pin was heavily wore at the frame pivot bushed areas. the pin needs to be replaced, as does the frame bushes. it was NOT an easy task getting the pin out. 10 lb sledge and a steel cold rolled round bar just smaller than the pin and a LOT of beating, heating and oiling over 4 days.