Older 643 Bobcat

[Hunch]

Hi people, new to this so please be gentle. I have a 643 and yesterday my RHS front wheel was turning by its self in forward. The rear didn't turn, but all good in reverse with both wheels driving. Please help TIA. Hunch

 

[flyerdan]

It sounds like you might have a drive chain off the rear wheel off, and it piled up and caused the wheel to drag going forward, and unrolled going back. It wasn't driving, per se, but freewheeling.
The quickest and easiest check would be to put a floor jack under the back, and use the bucket to get all for off the ground and see if you can turn the RR by hand. If it turns freely, or feels like a chain pileup might be binding in one direction, that's probably the culprit.
If it was something else, like a bearing binding up, one would think it would break or skip the chain drive and make a lot of noise.

 

[Hunch]

It sounds like you might have a drive chain off the rear wheel off, and it piled up and caused the wheel to drag going forward, and unrolled going back. It wasn't driving, per se, but freewheeling.
The quickest and easiest check would be to put a floor jack under the back, and use the bucket to get all for off the ground and see if you can turn the RR by hand. If it turns freely, or feels like a chain pileup might be binding in one direction, that's probably the culprit.
If it was something else, like a bearing binding up, one would think it would break or skip the chain drive and make a lot of noise.

Thanx flyerdan, I will check on the weekend

 

[Hunch]

Thanx flyerdan, I will check on the weekend

G'day guys, did as flyerdan suggested and the rear wheel rotates freely (possible broken chain or ...) My next question. Is it difficult to repair/replace and do I have to remove the pump to get to the drive sprocket?? I have a service manual, but it's not very detailed. Do I need the special tools as suggested in the manual (chain breaker MEL 1045 and chain link tool set MEL 1037)?? Are the parts readily available in the US as I'm in Australia and have had not a great deal of success locating parts here. Cheers and thanks for you input ... Hunch

 

[Tazza]

G'day guys, did as flyerdan suggested and the rear wheel rotates freely (possible broken chain or ...) My next question. Is it difficult to repair/replace and do I have to remove the pump to get to the drive sprocket?? I have a service manual, but it's not very detailed. Do I need the special tools as suggested in the manual (chain breaker MEL 1045 and chain link tool set MEL 1037)?? Are the parts readily available in the US as I'm in Australia and have had not a great deal of success locating parts here. Cheers and thanks for you input ... Hunch

The rear chains are the hardest to access, i think the pump needs to come out to access the inspection cover.
It really depends on how far you want to go with this. You can pull the pumps and do the chain. Or you can remove the chain case from the frame then do the chain and i'd suggest you do the axle seals. Again, it depends on how far you want to go.

 

[Hunch]

The rear chains are the hardest to access, i think the pump needs to come out to access the inspection cover.
It really depends on how far you want to go with this. You can pull the pumps and do the chain. Or you can remove the chain case from the frame then do the chain and i'd suggest you do the axle seals. Again, it depends on how far you want to go.

Thanx Tazza

 

[Hunch]

Thanx Tazza

G'day. Am I being stupid or just thinking outside the box? Are the drive chains the same length (ie: front and back) if so can I remove the drive motor, swap the front chain to the back and install the new chain on the front (easier access). Just curious ... Hunch

 

[flyerdan]

G'day. Am I being stupid or just thinking outside the box? Are the drive chains the same length (ie: front and back) if so can I remove the drive motor, swap the front chain to the back and install the new chain on the front (easier access). Just curious ... Hunch

According to the online parts catalog, all chains are the same part number, so it follows that they are the same length. A master link is called out as well, so it might be fairly easy to feed in a new one.

 

[Hunch]

According to the online parts catalog, all chains are the same part number, so it follows that they are the same length. A master link is called out as well, so it might be fairly easy to feed in a new one.

Cheers flyerdan