I'm at a loss for what it could be...thump..thump...thump

[Gilbey]

Well, I need some help diagnosing here. I'll tell you what the sled is doing, and they'll I'll tell you what it's not. I'm thoroughly confused, and currently my sled is pretty iced up so it's tough to diagnose. It'll be in a heated garage by this afternoon, which will tell me more than I know right now.

This thumping sound almost sounds like it's coming from the clutch side, secondary area, I can feel the thump.....thump.......thump......thump, so it's in time with the revolutions of either the clutch, track, or drive

So, here's what it is not:

Belt, same effect
Checked drive shaft bearing and jackshaft bearing, ok
Primary, ok
Secondary, not sure, but don't think so unless the shaft got slightly bent, but don't know how to tell this
Rear skid appears to be lined up and solid, a lot of ice build up though, so after some heat might know more there.
Chain case has oil stil in it, and no leaks indicated in the bottom.

So, I haven't checked the whole track, so this is what it COULD be:

Torn track at some point whacking the tunnel
Ice chunk that somehow didn't get kicked out for 16 miles
Bent drive?

Anybody else have this happen. I could feel the thump with my left foot in driving position. Felt like the drive lugs to me, or track got off, but all the lugs appear to be there.

 

[rx-1 blue reverse]

I would vote for Ice in the tunnel.

 

[4Fighter]

My guess would've been belt, but you tried that already. Is it possible you have two bad ones?

Check your drivers and lugs?

 

[Gilbey]

My guess would've been belt, but you tried that already. Is it possible you have two bad ones?

Check your drivers and lugs?

Drivers looked good. No lugs torn or ripped, or excess wear for that one. Bearings on the shaft didn't have play.

I'm guessing ice as well at this point. But have never in my years experienced a sound of this magnitude, it was a serious whack in the lower left floorboard area. And it didn't relieve itself after 16 miles, I never felt comfortable with my machine going over 20 mph. Seriously, one hour=16miles.

Have you guys experienced ice build up that you thought your machine was going to drop the drive axle on the trail as you drove?

That's really what I thought. I'm crossing my fingers.

 

[bdm]

Are you running it with the track off the ground? Seems like you sould be able to differntiate between track, driveline, and clutch noises when running like that?

 

[4Fighter]

My guess would've been belt, but you tried that already. Is it possible you have two bad ones?

Check your drivers and lugs?

Drivers looked good. No lugs torn or ripped, or excess wear for that one. Bearings on the shaft didn't have play.

I'm guessing ice as well at this point. But have never in my years experienced a sound of this magnitude, it was a serious whack in the lower left floorboard area. And it didn't relieve itself after 16 miles, I never felt comfortable with my machine going over 20 mph. Seriously, one hour=16miles.

Have you guys experienced ice build up that you thought your machine was going to drop the drive axle on the trail as you drove?

That's really what I thought. I'm crossing my fingers.

I've heard thumps and rattles and clicking sounds, and they go away eventually...bad belts and ice build-up.

Now, if you start to hear chirp-chirp from the same area. Then your speedo quits - Your drive axle bearing is going. BTDT.

 

[Gilbey]

Are you running it with the track off the ground? Seems like you sould be able to differntiate between track, driveline, and clutch noises when running like that?

No, I have not had a chance to get it back off the trailer as of right now. It will go in a heated garage to thaw the skid out and I have an engine hoist to do that. That will be the first thing looked at once the ice is melted this afternoon.

 

[RX1Maine]

I agree, I bet it is ice up in the tunnel