Speedometer-side driveshaft bearing!

[Erik in AK]

All,
For those of you not already aware...

Mounted at the end of your machine's driveshaft, opposite the chaincase, is the speedometer housing. On most machines this housing acts as a grease cap for the bearing also found at that end of your driveshaft.

There is a mortised hole in the end of your driveshaft that turns a square key linking it to the speedo.

If your speedometer stops working the probable cause is the bearing failed.

If you drive your machine, say, an additional 500-600 miles on a fried bearing you'll do additional damage to your machine.

On most machines you must remove your secondary clutch to check this but the secondary comes off as a complete assembly and it's not nearly as intimidating as it first appears, so there's no excuse for not checking this regularly.

Ask me how I know....

[AKDoug]

Yep. One of the most common things to come into a sled shop. " My speedo quit working last year and I don't know why, but I kept riding it until it went ughh... " New sleds, like the Cats with diamond drive don't have this issue..they just have more expensive issues

[mainer_in_ak]

One thing most folks don't realize, is that that bearing you are referring to is a SEALED BEARING. Grease it all you must, it won't grease the bearing. A snow machine genius (Kirk Wilson) taught me this. I took the speedo housing off and sure nuff.....it was a sealed one. I took the seal off considering this bearing is protected by a gasket anyways. Now......when I grease this new bearing, the grease will actually make it to the bearing. Kirk says' that since he's done this, he hasn't changed one since. Go ahead and pull the speedo housing.....you'll see what I'm talking about.

[mod elan]

Kirk is more familiar with Cats. As far as the skidoo's with cable driven speedos this bearing is open on one side and does get lube. I don't remember what the polaris bearing is like.

And the first thing I check on a sled where the speedo quits working is to see if the cable is froze or gummed up. Hate to see someone break down the drive axle only to find a bad speedo cable.

Interesting fact: Skidoo started sealing their chaincase bearings years ago. Always thought a bearing running in oil would last the longest. They evidently didn't like the idea of the chain and gear filings to circulate thru the bearing even though the dipstick magnet should pick it up.

[mainer_in_ak]

Yes, on a Polaris, it is sealed too. You're darned right about the speedo cable going bad! when you spin that thing thousands of rpm's, they do go bad, and can twist up too. I had to replace a twisted up cable, it was twisted at the spot that connects to the speedo housing.

[trailblazersteve]

As mainer said, the zirk is for speedo lubing only. Does nothing for the bearing. Many people are miss informed of this...

[mod elan]

The Doo's get grease to the bearing. No reason to have a grease zerk on the electronic speedos if this wasn't the case. Not all brands are the same....

[AKDoug]

Yes, on a Polaris, it is sealed too.

Not all Polaris are sealed. None of ours were.

[Donkey Hunter]

Not all the cats are sealed either. I dont think any of mine were.

[Nitroman]

I've had two Cat speedo keys twist off for some reason. But the bearing was fine.

[wingshooter12g]

Gonna try to pull mine off my 04' RMK 800. The speed ometer went out at the end of last season.

[cutty]

Pulled my off my Trail RMK. Bearing is shot. ordered parts to fix. Will this be hard to replace?
Right now drive shaft is pulled to one side, any tips or advice how to center this when installing new parts/bearing?

[ak_cowboy]

It should center itself. Install the speedo key first, then bearing, and bolt it up. It helps to have another hand in the tunnel holding the bolts, but doable if your arms are long and belly is skinny

sent from my igloo

[keh]

Cutty, Cowboy is right. The driver axle will center itself as you reinstall. Once backtogether, remember to retighten and align your track.