JAckshaft question

[boyerbl]

I am installing new #60 chain on my Jackshaft on my 91 MaxII. Every time I spin my wheels the chain binds up between the top and bottom gear. I know the shaft is out of alignment. I plan on using a caliper depth gauge to align the jackshaft to the frame. Question: do I automatically assume the lower gear is true to the frame? Also can I use the depth gauge to measure from the top of each side of the Jackshaft to the top of the frame. Observation: #60 chain has zero side to side tolerance and will tell you things are not lined up.

[Mike]

The lower sprocket should be true, perpendicular to the frame, since it rides on the axle. The axle doesn't have any adjustment front-back or up-down but it does have adjustment in and out of the machine. When I'm starting from scratch, I usually start by making sure the lower sprockets on all of the axles are aligned. Your axles will most likely be the same distances in the frame so that's one way to check. Also use a straight edge to check between sprockets. Once those are in place then you can shift the jackshaft left and right based on the number of spacers/washers you use on either side. Then the four nuts on the jackshaft adjustment plate will perform the final alignment to keep the jackshaft perpendicular to the frame. Hope that made sense.

[ARGOJIM]

The lower sprocket should be true, perpendicular to the frame, since it rides on the axle. The axle doesn't have any adjustment front-back or up-down but it does have adjustment in and out of the machine. When I'm starting from scratch, I usually start by making sure the lower sprockets on all of the axles are aligned. Your axles will most likely be the same distances in the frame so that's one way to check. Also use a straight edge to check between sprockets. Once those are in place then you can shift the jackshaft left and right based on the number of spacers/washers you use on either side. Then the four nuts on the jackshaft adjustment plate will perform the final alignment to keep the jackshaft perpendicular to the frame. Hope that made sense.

May be the eccentric on the bearing has broken at the locking collar, that is all in a 91 holding the axle in place, may have also simply let the axle walk out some moving the sprocket with it.

[boyerbl]

The bearing is new, with a flashlight. I can see a section of the lower gear holds the chain as it rotate going forward and as I rotate to the the rear. I might need a new lower gear. Has anyone come across a similar situation?

[boyerbl]

Tonight I plan on pulling the lower gear and inspecting it. My suspsion is the pitch is off due to wear and causes the short #60 chain to bind up. I will then be ordering a new drive gear.

[msafi65]

When you look as sprocket and chain books they always want a hanging chain tighter than a horizontal chain. They just try to climb on to the lower teeth. Also alignment in a max starts at the transmission. I slip the pins in the jackshaft before setting the axle bearings and get the output sprocket true with big sprocket on jackshaft. Then align the drop chain with axle by moving the axle in or out. Then lock the bearings to the axle. Good luck hope you are riding soon.

[Mike]

Also alignment in a max starts at the transmission.

That's a good point to start with what you can't change. I think I have just been lucky the way I was approaching it.

[boyerbl]

I put a new center sprocket assembly on and now everything runs like butter. On the old assembly the outside two #50 sprockets were ok but the inner #60 sprocket was messed up. The previous owner probably never adjusted the slack.