jack Shaft bearing kit - Snowmobile Forum: Your #1 Snowmobile Forum

93sportwithkids · 12-11-2012, 07:55 PM

I put an "All Balls" jackshaft bearing kit into my 94 Sport this past summer... the shaft that drives the track with the cog wheels. The bearing on the left side where the speedometer drive is was basically the same. On the gearbox side however my original open bearing was replaced with a 2 sided sealed bearing. I guess they feel their bearings are good enough that they no longer need the additional lubrication from the gearbox.

Anyone else run into this? Is this something new to expect? It probably doesn't matter as the left side is a sealed bearing too, but just thought I would ask if anyone else ran into this.

meburdick · 12-11-2012, 08:45 PM

If you think about it, the sealed bearing on the PTO side gets no additional lubrication *ever*, and it holds up well. Why would you need to introduce a "who-knows-what-quality" lubricant into the other side? If it's good for one side to be filled with an appropriate lubricant from the factory, it's good for the other side too.

In addition to lubrication from the chaincase, you were also getting small metal filings and general "sludge" in there from your degraded oil. It's actually better to be sealed on that side too.

**BC_Dan** · 12-11-2012, 09:00 PM

The shaft that the cogs are on that drives the track is the driveshaft. The jackshaft is the shaft that the secondary clutch is on, as well as the brake on most sleds. FYI

93sportwithkids · 12-11-2012, 09:13 PM

Thats what was sort of thinking... Most folks don't change their fluids that often.

For the older gen Indy's the Jackshaft kit and the driveshaft kit are the same part number, just you get an O-ring and spacer that you use only on the drive shaft.

Thanks BC-Dan... I'm getting more and more forgetful with age!!!

I changed my bearing as preventive maintenance. It was time. I don't like hiking out of the woods.

**BC_Dan** · 12-12-2012, 12:12 AM

Amen to that

**RJ Gleason** · 12-12-2012, 03:00 AM

X2 to that!
Preventive maintenance is cheaper than breakdown repairs.

rgoers · 12-12-2012, 02:12 PM

Quote:

Originally Posted by meburdick

If you think about it, the sealed bearing on the PTO side gets no additional lubrication *ever*, and it holds up well. Why would you need to introduce a "who-knows-what-quality" lubricant into the other side? If it's good for one side to be filled with an appropriate lubricant from the factory, it's good for the other side too.

In addition to lubrication from the chaincase, you were also getting small metal filings and general "sludge" in there from your degraded oil. It's actually better to be sealed on that side too.

Don't know about yours... but my bearing on the PTO side has a grease zerk, and it gets REGULAR lubrication.

meburdick · 12-12-2012, 09:41 PM

There's a zerk there, but that grease doesn't actually enter the bearing. The bearing is sealed.

93sportwithkids · 12-12-2012, 10:30 PM

I believe you are correct. The grease will sqeeze through the bearing holder on the back side and appear to go through the bearing, but it is not. The grease is actually there to lube the speedometer drive unit.

Changing those bearings is just not a fun job, and doing it in the cold, or worse yet outside in the cold would be no fun at all. Glad I got mine changed!!!

rgoers · 12-12-2012, 10:34 PM

Quote:

Originally Posted by meburdick

There's a zerk there, but that grease doesn't actually enter the bearing. The bearing is sealed.

"Sealed" is a relative term. Against water/dust under normal operating conditions... yes, they're "sealed". However - a grease gun exerts a LOT of force, and easily breaches the bearing seals. There wouldn't be a zerk there if the grease couldn't get into the bearing! I have read where some people actually remove the seals on the bearings before installing them, to allow grease to penetrate them more easily. That's really not necessary, as the pressure from a grease gun is sufficient to force grease past the "seals".

This is the same reason why you should never use a pressure washer near the bearings on your sled... pressurized water will easily make it past the "seals".