Author Topic: Crank seal Replacement question  (Read 3703 times)

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Rick

  • Guest
Crank seal Replacement question
« on: March 12, 2004, 10:34:12 AM »
I have not yet torn into the bottom end of my 2002 KX500, but think I have the wet side crank seal leaking oil into the engine.   Here's my question:  Can the wet side seal be changed without splitting the cases on a 2002 KX500?  

I know the newer KX250 cranks seal must be installed from the engine side, as there is a lip on the transmission side of the seal pocket that keeps you from driving the seal in from the transmission side.  However, since I have not taken my 2002 KX500 apart yet, I'm not sure if the seal pocket has a lip on the newer KX500's.  Anyone taken a 2002 apart yet to know about the seal pocket?

Manny, if no one has pulled a newer bike apart, can you check with John B. and see if the wet and dry seals can be changed on a 2002 KX500 without splitting the cases.

Thanks guys.

Rick

kawdude

  • Guest
Crank seal Replacement question
« Reply #1 on: March 13, 2004, 04:37:43 PM »
My 94 cannot be changed without splitting the case.  If you look on the kaw website the diagrams don't look any different.

Pinchy

  • Guest
How do you get the crank out the RH case once its split?
« Reply #2 on: March 13, 2004, 06:17:12 PM »
I got my 500 tore apart and the case split and the crank decided it wanted to stay in the Right Half of the case.
I took the clutch basket out of the way so I could heat the case up around the bearing. Didnt have much luck , maybe i didnt get it hot enuf but I got tyred of wasting propane and dont really feel like cranking up my acetyl
torch;) and I really dont want to bugger up the end of the shaft anymore.

Is it normally taken out with a press? I figure the next step would be take the rest of the tranny out and put it in a friends press.

And what are some good tips to removing the end bearings once its out?
Im leaning toward the caveman chisel approach myself. If i remember they had bearing pullers that looked like a guillotine sorta with 2 halves with the center sharpened to dig in behind the bearing but i bet youd run into problems coz the crank would be in the way of tool since it has such a large diameter.

kawdude

  • Guest
Crank seal Replacement question
« Reply #3 on: March 14, 2004, 02:51:55 AM »
Go to harborfreight online and order that bearing puller.  Normally its a .0005" press fit into the bearings and you won't be able to pull it off without it.  You may be able to heat the inner race enough to get it to pull without one.  Either way use heat.  I also believe you may need to pull the left case off first using a puller that pushes on the crank and pulls on the stator bolt holes.  Do a search on "rebuilding".  You should find a lot of info.

DanH1

  • Guest
Crank seal Replacement question
« Reply #4 on: March 14, 2004, 12:10:14 PM »
Be patient, take your time and buy, borrow, or rent the correct pullers! It will save you many headaches and $$. Remember the speed that the crank turns, so you really don't want to pound on it too much, and easy on the heat. In the long run you will be $$ and performance ahead.  


                                                                             Dan

Rick

  • Guest
Crank seal Replacement question
« Reply #5 on: March 15, 2004, 04:30:32 AM »
PLEASE DON"T BUT THAT POOR LITTLE ALUMINUM CASE IN A PRESS.  I also doubt that heat will work, as heat is going to expand all the metal, including the bearing race. Crank's come out really easily with the proper tool.  Years ago, I purchased a harmonic balancer puller from a used tool store.  It looks like a long thin "H" with a big screw right in the middle.  Because the space in the top and bottom part of the "H" is so wide, I was forced to use 3/8" bolts.  However, you will notice that no where on the case will a 3/8" bolt thread in, so I cut the threads off of the 3/8" bolt, center drilled the end of the bolt, and taped the hole for a little 8mm bolt that will screw into virtually all of the holes in the case.  Once the hole was taped, I purchased a long 8mm bolt with lots of threads, cut off the head, and screwed/loctited the threaded section of the 8mm bolt into the taped hole.  

Now that the press is ready to go, simply center the large press screw over the center of the crank and find a hole in the case that is directly under each end of your press.  Don't be affraid to remove a bolt in order to find suitable holes that are 180 degrees apposed.  If the two holes you are going to use are at different depths in the case (for example, you are using one hole for the clutch cover and one hole for a bolt that holds a bearing in place down inside the case), just add a few washers between the head of the 3/8 bolt and the press to compensate for the difference.  The idea here is to hold the press scress perfectly in line with the crank.  Also, make sure your new custom bolts are screwed in all the way.  You don't want them to be able to wiggle at all, as you risk damaging the threads in the case.

Once your press is install, tighten the center press screw and the crank will push right out of the case.  

On the bearing removal, you must use a clamshell type bearing removal tool to get between the bearing and the crank.  As you tighten the clamshell, the bearing will begin to move off the crank.  Once tight, use a press to remove the bearing.

A word of caution:  NEVER USE A HAMMER ON YOUR CRANK.  The lone exception is to tap the end of your crank after initial installation to relieve the bearing bind and help center the crank.  I learned this lesson the hard way, as I once use a hammer to assist in crank work (this was long, long ago).  The result was that I actually distorted one crank end just a few thousands.  Have any idea what a new crank cost??  I do, and it's not cheap.  It's about like purchasing a new cyliner, but worse.  In short, don't use a hammer on anything but the end of the crank, and then only use a dead blow hammer just to set the crank after initial installation.

On the crank seals, I have pulled so many motors apart over the years, I've lost track of which models allow seal replacement without splitting the cases.  It appears the 500 requires case splitting.  Yuk, I hate that job, as it tears up an entire Saturday!  Oh well, there's always Sunday for riding...

Rick