fatboycowen
ArboristSite Member
I just got finished doing the clutch side of my 385. New OE crank and bearings. Here's what i did:
First i read the workshop manual. The manual says to heat the case side to 200C (almost 400F), and to insert the bearing, and let it cool (this goes for each side). Then, use special tools to pull the crank through the bearing, one at a time. 400, holy moly.
I tried the Mastermind method. I heated the clutch side case with my heat gun. It took quite a while. I got the inside part of the case to 250F on my IR gun. I set the case down, crank side down, on top of an old, but clean piston, so that the bearing had a surface to stop at. The manual says to put the bearing flush with the inside of the case. The piston provided the stop.
At that temp, the bearing went right in, just as mastermind suggested.
I waited a few moments and tried inserting the crank. Not sure if i didn't get it hot enough or what, but the crank did not go in all the way. It went in about half way. I tapped gently the other direction, and it popped out. Tried again, no go. It was getting stuck just as the bearing got to the surface it will finally be on. It seems that this is a very tight fit.
So, i had the bearing in the case, now pretty much cool. Given that it's a plastic cage, i didn't want to heat the bearing. I was kind of freaked out, as i didn't want to do anything to damage the new 200 dollar crank, or expensive bearing.
So, I put the crank back through the bearing as far as it would go by hand. I took some appropriately sized washers and used them as spacers. The washers rest against the inner race of the bearing, and the ID of the washers is large enough to fit over the crank. I threaded the (clean) clutch onto the crank, and started turning the clutch with the clutch removal tool and wrench. As the clutch was tightening onto the crank, it presses against the washers, and pulls the crank into the bearing very effectively. I had to stop a few times to add washers, so that the clutch didn't bottom out. This worked extremely well, and was quite easy. As far as i can tell, this is the redneck version of the shop manual method.
I'm wondering if i should try the same method on the flywheel side. I'll have to be a little more creative with the washers, but it should work. On the other hand, the opposite bearing has a metal cage, so i could heat the bearing inside the case. But, i sort of like the idea of doing it the factory way.
Also, don't put the bearing in the wrong way, or the crank!
Thoughts?
First i read the workshop manual. The manual says to heat the case side to 200C (almost 400F), and to insert the bearing, and let it cool (this goes for each side). Then, use special tools to pull the crank through the bearing, one at a time. 400, holy moly.
I tried the Mastermind method. I heated the clutch side case with my heat gun. It took quite a while. I got the inside part of the case to 250F on my IR gun. I set the case down, crank side down, on top of an old, but clean piston, so that the bearing had a surface to stop at. The manual says to put the bearing flush with the inside of the case. The piston provided the stop.
At that temp, the bearing went right in, just as mastermind suggested.
I waited a few moments and tried inserting the crank. Not sure if i didn't get it hot enough or what, but the crank did not go in all the way. It went in about half way. I tapped gently the other direction, and it popped out. Tried again, no go. It was getting stuck just as the bearing got to the surface it will finally be on. It seems that this is a very tight fit.
So, i had the bearing in the case, now pretty much cool. Given that it's a plastic cage, i didn't want to heat the bearing. I was kind of freaked out, as i didn't want to do anything to damage the new 200 dollar crank, or expensive bearing.
So, I put the crank back through the bearing as far as it would go by hand. I took some appropriately sized washers and used them as spacers. The washers rest against the inner race of the bearing, and the ID of the washers is large enough to fit over the crank. I threaded the (clean) clutch onto the crank, and started turning the clutch with the clutch removal tool and wrench. As the clutch was tightening onto the crank, it presses against the washers, and pulls the crank into the bearing very effectively. I had to stop a few times to add washers, so that the clutch didn't bottom out. This worked extremely well, and was quite easy. As far as i can tell, this is the redneck version of the shop manual method.
I'm wondering if i should try the same method on the flywheel side. I'll have to be a little more creative with the washers, but it should work. On the other hand, the opposite bearing has a metal cage, so i could heat the bearing inside the case. But, i sort of like the idea of doing it the factory way.
Also, don't put the bearing in the wrong way, or the crank!
Thoughts?
