inner race removal from crank

Bought a complete 750 motor with an extra set of cases awhile back, tear down went smoothy, but I've struggled with this b*tch of an inner race for awhile now, finally received a clamshell bearing splitter in the post, but it still took lots of patience and heat until she finally came off. I didn't want to to mar the already iffy threads on the end of the crank, so I stacked some pipe fittings onto the shouldered portion.



also had to smooth and clean up some roughness and nicks at the cheek ridge, but came out nicely after all was said and done



anyone know what the thread size is on the drive side/rotor end? I need to source a proper die to clean them up

The dive side thread is a 5/8-20.

In the future it is easier to pull the inner bearing race by using a die grinder to cut deep slots on opposing sides, your clam shell will bit in with a lot less squeeze, making it much easier to remove the race. Of course if you only want to add shims under the race then cutting slots will be quite counter productive...

Another trick - arc/TIG weld a bead all the way around the race; turn it upside down and in a moment or two, it will find its temp delta/clearance and fall off.

RoadScholar said:

The dive side thread is a 5/8-20.

In the future it is easier to pull the inner bearing race by using a die grinder to cut deep slots on opposing sides, your clam shell will bit in with a lot less squeeze, making it much easier to remove the race. Of course if you only want to add shims under the race then cutting slots will be quite counter productive...

Click to expand...

5/8 x 20????

5/8" diameter, 20 threads per inch...

A lot of precarious stored energy in that set up. Suggest the next time you invest in some all thread rod or long bolts to thread into the clam shell puller and through a very stiff cross bar on top.

I visualize clamps and things flying off and hitting people or things with the set up below. Glad it worked out for you.

acadian said:

Click to expand...

The final solution is to fully get a puller setup. You know you are there when you can pull bearing race almost without any challenge again and again and again to the point that even pulling the race to add shims if needed is of very low concern. I never ever use heat....

Making crank end caps to thrust against prevents smashing the threads on the drive end or the oil quill on the timing side.

Also looking at your drive side you can see all the linear scoring across the seal surface...based on what I see you will almost certainly not be able to seal engine oil in. I have side lined crank cheeks much better than that.

dynodave said:

The final solution is to fully get a puller setup. You know you are there when you can pull bearing race almost without any challenge again and again and again to the point that even pulling the race to add shims if needed is of very low concern. I never ever use heat....

Making crank end caps to thrust against prevents smashing the threads on the drive end or the oil quill on the timing side.

Also looking at your drive side you can see all the linear scoring across the seal surface...based on what I see you will almost certainly not be able to seal engine oil in. I have side lined crank cheeks much better than that.

Click to expand...

admittedly, my set up was a bit of a hack job, but worked and prevented damage to the threads, I do intend on fashioning a proper puller rig with a collar resting on the shoulder.

the seal surface scoring is an issue, but that's why I've ordered a speedi sleeve

I had a similar problem and got mine off using RoadScholars method. I used a small angle grinder making sure not to go too deep! Applied some heat with a blow torch and it came of using a conventional bearing race puller. Made a loud crack sound when it decided to finally move. Sure was on tight.

I used a Dremel tool with a circular cutter tip to create 2 slots opposite each other on that inner race (being very careful not to nick the crank) , then a little heat-gun fun and a pull off easy with thick leather gloves. Mind you it was the original 2 bearings that had to go , to fit the new superblends.