need help installing crank oil seals

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seanstrx276
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need help installing crank oil seals

Post by seanstrx276 »

How do you get the crank seal in? I cant push it by hand, and I dont want to ruin it by hitting it with something....

Also, how do you guys get your bearings in? This is the first bike I have had where the oil seal is behind on the crank bearing. Usually i heat the cases, freeze the bearings to get the bearings in.. but in this case I am afraid of ruining the seal if I get it to hot.

Thanks for any advise,

Sean
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Colorado Mike
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Post by Colorado Mike »

I haven't done seals on a KDX, just Yamahas, so this info might be worth what it cost you. To set the seal, I have some seal drifts that I got from Harbor freight, but you can use a big socket just as well. I put a little white lithium grease on them too. I get them lined up right and then tap in with a shot-filled mallet. As for getting the bearings in, check your grocery stores to see if they sell dry ice. that gets the bearings colder than your freezer. A little heat on the case from a plumbing torch, and they should drop right in. I don't know what to tell you about the seal being placed inside the bearing or what ever they do on the Kawy. The Yamies let you change seals without splitting the cases, just gotta pull the magneto on the left and disassemble the clutch, primary gear and water pump on the right.
Mike

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kawagumby
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Post by kawagumby »

I heat the cases in my kitchen oven, that way I can set the thermostat to whatever I want (usually something like 140- 160 degrees) so I don't accidentally ruin something by having a hot spot. I don't recall ever having a problem installing case seals into a warm case.
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canyncarvr
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Post by canyncarvr »

Re: 'This is the first bike I have had where the oil seal is behind on the crank bearing.'

Explain 'behind'?

What bikes have oil seals INside the bearing? As in, case-bearing-seal. Bearing lubrication is a bit hard to come by that way, isn't it?

That making no sense a'tall, I probably misunderstand what 'behind' means.

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Use an arbor press, or maybe a large C-clamp with an associated and properly sized presser/backer.

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RBD
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Post by RBD »

"CC", I think he is refuting to the fact that the seal is between the case and main bearing and the seal has to go in from the inside of the engine case first. It is pressed into the case until it hits a shoulder. Then the main bearing is installed.

There are a lot of two stroke engines that you can replace the seal from the out side of the main cases without having to split the cases. But, with the KDX and other engines you must split the cases in order to replace the crank seal.

"Sean", I usually use a large socket that is just a little smaller than the seal OD and drive it in with a mallet. Just make sure that the seal seats against the shoulder in the case and make sure to install it in the right direction.

Warming the case to about 150* like "Kawagumby" said, will help- with the bearing installation and not hurt the seal.

Ron
seanstrx276
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Post by seanstrx276 »

Ron hit the nail on the head. I will try that and see how it works.

Thanks for the help everyone,

Sean
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