2003 RX-1 jackshaft alignment

[Swaff]

All right I need some help because I'm out of ideas.

I noticed one day the snapring on the end of my jackshaft that holds the brake disc on was just hanging onto the tip. I tried to put it back on (with the two spacers that go behind it) but there's not enough of the shaft protruding from the disc to be able to get even just the snapring on, much less the spacers as well.

So either the jackshaft has started to migrate towards the clutch side of the sled, or something on the chaincase side has moved.

I opened the chaincase up and sure enough the large nut that tightens down against the upper sprocket was loose. I tightened it down, put everything back together, and still no change.

So I can't figure this out. If the shaft has moved towards the clutch side of the sled, why? And why won't it move back? I tried hammering on it to see if it would shift but it won't budge. From what I've read you're supposed to tighten the chaincase down first then the clutch side locking collar. I don't have the tool, or know of the tool, needed to loosen the locking collar (perhaps an addition of the previous owner because from what I can tell this wasn't a 2003 part) but even so, I don't understand how that would prevent the shaft from moving towards the chaincase side. From what I can tell, the two bearings at either end are the only things holding the shaft in place if the clutch and chaincase nut are removed.

Now if it's not the shaft that's out of alignment, but rather something on the chaincase side, then I'm stumped there too. I replaced the chaincase two season ago and the track last season, so I've had it apart a few times. But everything went back together fine, so something has changed over last season. The case is flush against the frame, the cover is flush on the case. The spacers I've got is one between the sprocket and the nut, then on the outside of the case I've got the collar with the torx set screw pushed right up against the bearing and then a spacer and then the brake. Then there should be two more spacers and the snapring but of course they won't fit.

When the nut is tight against the sprocket, there are about two threads showing, so for those familiar with it that's how far up the shaft the nut is.

I've never had the jackshaft out myself, but it's possible the previous owner did or another mechanic that's worked on it.

So yeah, I'm stumped. Any help would be greatly appreciated.

 

[Brian A]

I have been thinking about this since I saw it last night

I just did my track and put a mono skid on my 03 RX1 so I was just working on this area.

I would take the secondary off and make sure the jackshaft's bearing snap ring is in place and that the bearing is seated in the frame.

I also wonder about the sprocket nut being loose. Thats odd

The PO might have been in there and changed the jackshaft bearing and did not put the snap ring in and it walked out.

I would also check that bearing and the driveshaft bearing at the speedo, both need service every so often, there is info on in this in the Tech section

 

[Redbeard]

It's possible that the clutch side lock collar is mostly tight, but vibration and use has allowed the shaft to walk, especially if the large nut inside the case was loose.

You can use a hammer and chisel to loosen that collar. At least that worked for me in the past. It might be time to just remove the entire shaft and install a new bearing.

 

[Swaff]

Thanks for the reply guys.

Brian, yes I did take the secondary off and the snap ring is in place and the bearing is seated. The sprocket nut probably just wasn't tightened down enough the last time it was apart. I do lube both of the clutch side bearings annually.

I guess the next step is to try to get that collar loose and see if that helps things any. I assumed that the collar would pull the bearing (and shaft) towards the chaincase side of the sled when tightened, but maybe it tightens on the shaft itself? I haven't seen it, so I don't know how it works.

 

[Redbeard]

maybe it tightens on the shaft itself?

The inner race of the bearing is tapered. The collar draws the wedge into the bearing and creates the needed interference between the bearing and shaft.

If memory serves, I assembled the chain case innards and tightened the large upper sprocket nut first. Then tighten the collar to set the wedge on the clutch side last. That should allow the jackshaft to rest in the correct position before the wedge is locked in place. It's been a while, so might confirm first.

I found this old post from LAKERCR. Good info!

https://ty4stroke.com/threads/jackshaft-bearing-r-r.34713/

 

[Swaff]

That old post is good info and it was turned into a how-to that I read. I have read to tighten up the chaincase side first, then the clutch side.

So I got the collar loose, and it didn't change anything. So I decided to take the chaincase apart and pull the jackshaft right out, which I did.

I now see how that collar works. I also came to realize that there's a snapring on the jackshaft that would prevent the jackshaft from moving any further towards the chaincase side.

But anyway, I think I finally have the problem figured out: Extra parts, and parts in the wrong place. When I pulled out the jackshaft, left in the tunnel were, in order looking from the chaincase side to the clutch side, a collar and a washer/spacer. I believe I've identified the collar as the one that belongs on the inside of the chaincase between the sprocket and the case bearing. I still can't figure out what the washer is from.

A number of years ago I took the sled to a local dealer and had them do a once-over on it. I know they replaced the jackshaft bearing. After getting it back and on my first ride it broke down. Before that dealer to could look at it again, they went bankrupt. Another dealer fixed the sled and diagnosed the problem as a broken chain due to a backed-off tensioner. So the dealer made at least one mistake and I think this is another.

Since then, the post on which the tensioner rotates sheared off. I replaced the chaincase myself. A year later I replaced the track. So I've had the case apart a few times myself, but never the jackshaft or the bearing. I think because of the tight collar on the clutch side, the chaincase went back together and stayed together mostly ok, despite that collar not being behind the sprocket. And although I know I said I've put it together a few times, in hindsight I don't think the snapring on the end of the shaft that holds the brake on (the thing that started this whole odyssey) never was actually seated in the groove, because I think the mystery washer was on the shaft up against the snapring that is behind the chaincase, which caused the shaft to be 2mm too far towards the clutch side. Somehow that snapring on the end of the shaft that holds the brake on has hung on for many seasons despite not being in the right place.

Now when I put the chaincase back together everything seems to go together as it should.

I'm going to replace the jackshaft bearing and the clutch side driveshaft bearing while I've got it all apart. As per this how-to https://totallyamaha.com/snowmobiles/aaTECH/Jackshaftreplace/Jackshaftchange.htm I need to find a 2" piece of pipe to hammer the jackshaft bearing in with. As well, I noticed that in the how-to there are two washers that go on the jackshaft between the bearing and the clutch, one with a recess in it, and the other one. It's that other one that I seem to be missing. Anyone know the part number? The parts diagram is a little confusing because it includes all of the parts of the clutch itself. I did check to see if this mystery washer is it, but it's inner diameter is bigger than the shaft, so I don't think so.

Thanks again for all the help.

 

[Brotherdan]

That old post is good info and it was turned into a how-to that I read. I have read to tighten up the chaincase side first, then the clutch side.

So I got the collar loose, and it didn't change anything. So I decided to take the chaincase apart and pull the jackshaft right out, which I did.

I now see how that collar works. I also came to realize that there's a snapring on the jackshaft that would prevent the jackshaft from moving any further towards the chaincase side.

But anyway, I think I finally have the problem figured out: Extra parts, and parts in the wrong place. When I pulled out the jackshaft, left in the tunnel were, in order looking from the chaincase side to the clutch side, a collar and a washer/spacer. I believe I've identified the collar as the one that belongs on the inside of the chaincase between the sprocket and the case bearing. I still can't figure out what the washer is from.

A number of years ago I took the sled to a local dealer and had them do a once-over on it. I know they replaced the jackshaft bearing. After getting it back and on my first ride it broke down. Before that dealer to could look at it again, they went bankrupt. Another dealer fixed the sled and diagnosed the problem as a broken chain due to a backed-off tensioner. So the dealer made at least one mistake and I think this is another.

Since then, the post on which the tensioner rotates sheared off. I replaced the chaincase myself. A year later I replaced the track. So I've had the case apart a few times myself, but never the jackshaft or the bearing. I think because of the tight collar on the clutch side, the chaincase went back together and stayed together mostly ok, despite that collar not being behind the sprocket. And although I know I said I've put it together a few times, in hindsight I don't think the snapring on the end of the shaft that holds the brake on (the thing that started this whole odyssey) never was actually seated in the groove, because I think the mystery washer was on the shaft up against the snapring that is behind the chaincase, which caused the shaft to be 2mm too far towards the clutch side. Somehow that snapring on the end of the shaft that holds the brake on has hung on for many seasons despite not being in the right place.

Now when I put the chaincase back together everything seems to go together as it should.

I'm going to replace the jackshaft bearing and the clutch side driveshaft bearing while I've got it all apart. As per this how-to https://totallyamaha.com/snowmobiles/aaTECH/Jackshaftreplace/Jackshaftchange.htm I need to find a 2" piece of pipe to hammer the jackshaft bearing in with. As well, I noticed that in the how-to there are two washers that go on the jackshaft between the bearing and the clutch, one with a recess in it, and the other one. It's that other one that I seem to be missing. Anyone know the part number? The parts diagram is a little confusing because it includes all of the parts of the clutch itself. I did check to see if this mystery washer is it, but it's inner diameter is bigger than the shaft, so I don't think so.

Thanks again for all the help.

Sorry just came upon this post,not sure if you found your answer but the plain washer your talking about is used on the 2005 or the upgraded 2003 using the retainer nut instead if the original collar style,the plain washer your looking for is part#90201-25289-00.the other washer your talking about should go where you found it &should be part#90201-30666-00

 

[Swaff]

Sorry just came upon this post,not sure if you found your answer but the plain washer your talking about is used on the 2005 or the upgraded 2003 using the retainer nut instead if the original collar style,the plain washer your looking for is part#90201-25289-00.the other washer your talking about should go where you found it &should be part#90201-30666-00

Awesome, thank you very much.