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Discussion Starter #1
I’m rebuilding this bike and motor and got a little stuck on this seal. Where the clutch push rod is there is a seal that has a ridge around it that I believe fits into a groove in the case. First attempt to install and I ripped the ridge on the seal.

Any suggestions to getting that in there? I can have an indoor dent local bike shop put them all in fit around $200 but I already have all the seals and bikes project funds are getting short.
Thanks for any suggestions.
 

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By the size of that ridge it looks like it can only be installed from one side. Photos would help.
 

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There are many times seals require splitting the cases for proper instillation. This is quite often not a reasonable solution. In 1983 I purchased a very early GS550ED, the right crank seal almost immediately started to leak, oil on my boot. I managed to replace the seal successfully without splitting the cases. The following is what I would try, no guarantees but this is based on fifty years as a mechanic. I would buy several seals. First attempt would be with a fully intact seal, put in freezer to harden rubber, lube OD with white lithium and drive in with seal driver. If this did not work I would start to progressively sand down the bead, apply sealer, NOT RTV, RTV has very long chain molecules and would allow the seal to pop out under even slight pressure. Remove the bead in stages, remove as little as possible until you can successfully install seal. I would rather go thru 3 or 4 seals than split cases. Good luck.
 

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Discussion Starter #5
Thanks for that info. I have thought of freezing the seal and then heating the case with a torch before trying to get it in. The seals are about $30 a piece so I think I have about one more shot before I take it to someone who knows what their doing.
 

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1981GPZ550 is correct. This oil seal requires splitting the cases (I looked it up to confirm).

What a stupid design. I agree with 1981GPZ550 that you should try every possible means to avoid splitting the cases, even if that means removing 100% of the "ridge" on the seal, and using some kind of bonding agent to retain the seal. I would even consider not using bonding agent if the seal drives in nice and tight.
 

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Discussion Starter #7
It’s a super tight fit so my last resort would have been to, possibly, shave the ridge, put in some kind of sealant in the groove and then pound it in.
As I’m not super familiar with this set up, I can’t imagine there’s a ton of pressure but possibly oil would leak out without a good seal in there.
Thanks for all the help guys.
 

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Making assumptions here that your seal outside diameter is approximately one inch and that the material is Viton and that your deep freeze is at -30 F.

If the above assumptions are all true, then you can shrink that seal by almost ten thousandths of an inch (0.010").
That's a lot and that seal should just slide right in as long as there is no ridge on the seal. If you don't have a proper seal driver then use a socket that is just a bit smaller than the outside diameter of the seal.

The seal will warm quickly so work fast. Good luck!
 

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Discussion Starter #10
It seems that the ridge is closer to the side that first goes in the engine so, it’s hard to tell. I believe that, without splitting the case, the seal would be tight enough to keep the oil from leaking.
There has to be a reason for the ridge in the seal and a groove in the case on a functional level wouldn’t you think?? It’s breaking my brain.
again I appreciate all the help.
 

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To test for fit, just turn the seal around and gently try to press it in. That will give you some idea of the kind of fit you will achieve if you remove the entire ridge. If you have access to a digital caliper you could measure the seal and the bore it fits into to see what you are dealing with.

I expect the main reason for the ridge is to locate the seal in the correct position and keep it there during crankcase assembly and later during operation. Since the crankcase is vented, there should be very little, if any internal pressure so the only things that could move the seal is engine vibration and the lip resistance as the clutch push rod goes in and out. Neither of those forces would be very large. If you were really worried about it, then after the seal is installed you could put 3 or 4 dabs of epoxy around the circumference of the seal.

Seals are normally installed up against a shoulder which locates the seal axially and corrects any slight misalignment of the seal. Since Kawi decided not to use a shoulder in this case, the groove and ridge provides those two functions.

Because you are eliminating the ridge (or at least most of the ridge) you will need to make sure the seal is nice and square as it goes in and that it stays square when it reaches its final location. You will have to determine final location by measurement.
 
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