OMC 1200A variable sheave (driven) replacement

[ta]

I have an OMC Mustang 1200A. The fixed half of the variable sheave has worn and wobbles on the jackshaft. I have a parts manual but not a service manual. Before I rip into it, I'd really like to know a little more than the parts book shows about what connects to the left end of the jackshaft, and any gotcha's there may be during the R&R. Does anyone have experience changing one of these, or maybe a service manual that you wouldn't mind "summarizing" the replacement procedure? Thanks! Tim

 

[skidsteer.ca]

Sorryhave onlt worked on the snowmobile ones. But other then the spring that holds the driven shut trying to push it open there is not to much toworry about. When you take it apart keep trackof how much one 1/2 winds the spring up compared to the other half.
Make sure the bushings are tight on the shaft so both disks run parallel to each other and that you change the plastic buttons on the ramps (helix) This is asumming its the same as a sled in design.
Maybe post us some pics to look at.
Ken

 

[ta]

Sorryhave onlt worked on the snowmobile ones. But other then the spring that holds the driven shut trying to push it open there is not to much toworry about. When you take it apart keep trackof how much one 1/2 winds the spring up compared to the other half.
Make sure the bushings are tight on the shaft so both disks run parallel to each other and that you change the plastic buttons on the ramps (helix) This is asumming its the same as a sled in design.
Maybe post us some pics to look at.
Ken

I'm not so worried about getting the sheaves apart / back together, I've done tons of those on sleds, go karts and junior dragsters. This one actually looks easier since it doesn't use rotation & torque to set the belt depth. (no ramps or buttons / rollers either)

I have to split the jackshaft to get the sheave off and I'm more concerned about what's connected to the gear at the end of the jackshaft where it goes through the side wall of the engine bay.

I know there's a bearing that the end of the jackshaft rides in, and there's a gear on the end of the jackshaft that I assume runs a chain to the hydraulic pump. But, since that's on the other side of the wall. I can't see the chain without taking off the wheels and the access plate on the outside.

I was hoping someone here had been inside one of these and might have tips / tricks for getting in there and removing the jackshaft half without ruining the seals, etc.
Thanks!
Tim

 

[longrev]

I'm not so worried about getting the sheaves apart / back together, I've done tons of those on sleds, go karts and junior dragsters. This one actually looks easier since it doesn't use rotation & torque to set the belt depth. (no ramps or buttons / rollers either)

I have to split the jackshaft to get the sheave off and I'm more concerned about what's connected to the gear at the end of the jackshaft where it goes through the side wall of the engine bay.

I know there's a bearing that the end of the jackshaft rides in, and there's a gear on the end of the jackshaft that I assume runs a chain to the hydraulic pump. But, since that's on the other side of the wall. I can't see the chain without taking off the wheels and the access plate on the outside.

I was hoping someone here had been inside one of these and might have tips / tricks for getting in there and removing the jackshaft half without ruining the seals, etc.
Thanks!
Tim

I just replaced the driven variable, and you have to take the tires and access panel off, then the loosen the chain and slip it off the cog. Then remove the cog. Then remove the four bolts holding on the bearing, and remove the bearing with a puller. Then you can remove the jackshaft. Oh, don't forget all the set screws and coupler on the other side. Hope this helps. Let me know if you have any questions.