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Help installing a crank!!

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Can anyone give me some advice on installing a crank without a crank installer??

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assuming you've got it apart already and the old main bearings out. Put the crank and main bearings in the freezer for a few hours ( I usually leave in for about 4-6 hours). Right before you're ready to start installing, put the cases in the oven around 225(you may search for the temps most people use). Take the cases out and quickly grab the bearings out of the freezer. They should almost drop right in. You can use the old bearings to help drive them home if necessary. DO NOT tap on the new bearings directly with any kind of force, ESPECIALLY the inner race. Then go grab your nice frozen new crank and it will literally drop right into the main bearing. Some people say to heat a piece of metal to 400 or so and put it to the main bearings inner races, but mine dropped right in without this. Then throw your tranny back in and put the other case half on over the crank. It should slide down enough that you can start pulling it back together with the case bolts assuming you dont move at a snails pace.

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I have done mine in two phases. First freeze the bearrings and heat the cases, then freeze the crank and heat the cases again. Also make sure to install the new crank seals before installing the main bearrings or at least that is how both of the KDX's I've done have gone.

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I have done mine in two phases. First freeze the bearrings and heat the cases, then freeze the crank and heat the cases again. Also make sure to install the new crank seals before installing the main bearrings or at least that is how both of the KDX's I've done have gone.

You are correct, the main seals go in before the bearings. This is the reason you cant reheat the entire case halves themselves once you have the bearings in to drop the frozen crank in. It may melt the seals. This is why some use a metal slug and heat it to about 400 degrees and put it on the inner race of the main bearings. The mains are steel and wont hardly expand at 200* anyways.

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Dont worry about it. You can reheat the cases with the seals in place. Those seals see much higher temps than that. Have done it 100s of times, zero failures.

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Yeah, 200 isn't that hot.

One thing I'd add is after you assemble the bottom end, try rotating the crank. If it feels tight at all tap the ends of the crank with a brass drift and a hammer to center it. Sometimes the crank and bearings bind a little during assembly.

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I keep hearing people talk about crank installers. Just curious do you mean a crank centering tool or the fixture to keep the crank from having the lobes bend in while pressing it in.

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You are correct, the main seals go in before the bearings. This is the reason you cant reheat the entire case halves themselves once you have the bearings in to drop the frozen crank in. It may melt the seals. This is why some use a metal slug and heat it to about 400 degrees and put it on the inner race of the main bearings. The mains are steel and wont hardly expand at 200* anyways.

That's silly. 200 degrees is not going to melt the seal. And the idea here is temp DIFFERENTIAL. If the bearing is 200f and the crank is 32f, the temp differential gives enough play for it to slide in.

At any rate, I have done several bottom ends this way recently, and it works perfectly well.

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That's silly. 200 degrees is not going to melt the seal. And the idea here is temp DIFFERENTIAL. If the bearing is 200f and the crank is 32f, the temp differential gives enough play for it to slide in.

At any rate, I have done several bottom ends this way recently, and it works perfectly well.

I suppose you are correct, I' just never wanted to be the test dummy to find out, haha.

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