Bad Crank Seal? - Snowmobile World : Your #1 Snowmobile Forum

DS800 · 05-23-2006, 12:27 PM

The other day I was cleaning up my 03 Rev 800 and noticed what appears to be an oil leak on the clutch side of my engine around the crank seal. Is this a sign of a bad crank seal or something worse? I intend to do the rings over the summer and install a V-Force reeds so if it needs to be done I'd like to do it all in the off season. So is it a bad seal or nothing to worry about? Any info would be a great help. Thanks

idooski · 05-23-2006, 12:33 PM

Quote:

The other day I was cleaning up my 03 Rev 800 and noticed what appears to be an oil leak on the clutch side of my engine around the crank seal. Is this a sign of a bad crank seal or something worse? I intend to do the rings over the summer and install a V-Force reeds so if it needs to be done I'd like to do it all in the off season. So is it a bad seal or nothing to worry about? Any info would be a great help. Thanks
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It depends a lot on what you are seeing, how much of it there is, and how long it's been since you cleaned the area.

Could you fill us in and maybe post a pic?

SnoKing · 05-23-2006, 12:34 PM

Start it up,and while it is running spray some starting ether behind the primary. If the motor starts reving up the seal is bad. I found some oil by one of mine but it was leaking around from the exhaust flange.

me&mymxz · 05-23-2006, 08:18 PM

It has been know to happen on the 03. Doo started putting retainers on newer models
Can get you more info if needed

DS800 · 05-24-2006, 02:26 AM

Quote:

It depends a lot on what you are seeing, how much of it there is, and how long it's been since you cleaned the area.

Could you fill us in and maybe post a pic?
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Unfortunately I didn't take any pictures before I cleaned it so I can't provide them. I can tell you that the sled seems to run perfect, idles without any problems and always starts on the second or third pull. The oil isn't real heavy or soaked but it definetly seems to be slinging from the crank as it's a circle around the crank. I hadn't pressure washed it before last season so it could have been building up for a long time but I realy can't say for sure. Thanks again for the help.

idooski · 05-24-2006, 08:41 AM

Quote:

Unfortunately I didn't take any pictures before I cleaned it so I can't provide them. I can tell you that the sled seems to run perfect, idles without any problems and always starts on the second or third pull. The oil isn't real heavy or soaked but it definetly seems to be slinging from the crank as it's a circle around the crank. I hadn't pressure washed it before last season so it could have been building up for a long time but I realy can't say for sure. Thanks again for the help.
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That PTO seal can weep some and not be considered 'blown'. Sometimes the bearings can be too full of isoflex when assembled. If the vent tube has a cap on it that is too tight, it will force some of the grease out through the seal. This will be a very small amount. The spray will probably not make it any farther than the engine itself. If you have spray on the area below and in front of the clutch then the seal is probably bad. The spray from a bown seal will look like grease thrown around and there will usually be big globs of it stuck to everything including the underside of the clutch cover. I had this happen to my '03 800. It still runs fine because there is an inner seal to the case as well that is on the other side of the two end bearings. That PTO outer seal has no access to the case. The ether trick will not work for that seal.

You should have your dealer look at it and tell you for sure.

rob7374 · 05-24-2006, 04:17 PM

Time to change the seal. If you go to DooTalk "AIRDOO" sells a retainer kit for like 35 buck us. It's cheap and easy to install and will stop the seal from walking out. Yours isn't likely walking out but it can and will happen to the earlier 800's. I've posted all of this before but I'll paste it all again

"I should mention it IS possible to replace the seal without splitting the case. You can dig the old seal out using something small like a dental pick and small screwdriver. Word of caution here. Do NOT mark the crank up. Try not to even touch it. If you mark up the crank the seal will leak. You will need to pick up some ISOFLEX as well. This is the grease they use for the bearings and seals. You can get it from any dealer but you pay through the nose for it there. You can also go to just about any auto parts store and order iso flex topas nb 52. It's the same thing but about 1/2 the price. Fill the back side of the new seal and using a plastic syringe from a drugstore, or maybe you have a stock of your own inject it into the bearing a well. Clean off as much of the old grease first. You should need about 30-40 ml of grease. Use some sort of seal grease or o-ring oil on the lip of the seal and the crank. You can also use some on the outer edge of the seal to help with installation. Sometimes guys use RTV silicone on the outer edge. It's up to you. Failure to lube the lib and crank will lead to early failure of the seal lip. Then carefully install the well lubricated seal using a PVC pipe fitting of the correct diameter and a rubber hammer. You can also use a big socket if you have. It does tend to help if the seal is good and warm. Not hot hot but warm and flexable. Once installed make sure you put the seal retainer back on. These were standard in 04 but many earlier Series III engines do not have them. Starting in 2006 on the series III engines the isoflex nipple cap has a small hole in it right from the factory. This is to allow expanding grease and/or air to escape. This is done to protect the inner seal as well. Unfortunately the grease tends to seep out and make a mess The inner is vulnerable to leakage caused by overpressure. Why ? Because the factory tends to overfill the cavity. You are far better off installing a breather to better fix this issue as it avoids the mess and any excess grease that gets pushed into the tube is available to get pulled back into the bearing as it cools down. With your primary off you'll see a little brass nipple with a plastic press fit cap on it coming out of the case. Pull the cap off. Now go and get about 2 feet of 1/4" inner 3/8" outer diameter tubing, 2 wire hose clamps and an air breather filter for 1/4" tube. Clamp one end of the hose to the breather on the case and route the hose up the frame member. Be sure to run the hose inside the torque arm so there is no possibility of the clutch grabbing it. Cap it off with the breather. What you will find when you run the sled is that ISOFLEX will run up the tupe. It's supposed to do that as the isoflex expands when hot. Some will re-melt and go back down into the bearing area as needed. Do not freak out over it and try and push it back in and recap it. You will blow the INNER seal since have the outer retainer.
Remember the seals start to leak because of too much iso in the cavity, by Rotax, under pressure because of a hot engine and a capped port, Remember the heat expands the iso and has to go somewhere. This was and is a problem with the 01-03 800's. The 04's and up have the seal retainer which keep the seal from popping out but it can still leak. IMO there are no downsides and it's just extra insurance. Hope this helps.

Link to the whole post

hillpounder · 05-28-2006, 08:21 PM

Normal to see a little grease on the outside of the seal, spread it around and add some belt dust to it and looks worse than it really is.

Like someone posted the seal lips are greased upon assembly, this is mostly what it is. Doo uses a specific grease for the seals BTW, another Kluber product simular to the bearing grease.

You don't want the seal pushing out but unlike other engines you won't lean burn down if this seal leaks, there's another inner seal.