hi all can you please help and advise. The front right bobcat drive has been a bit clunky recently. Today I noticed it was not driving at all. When raised off the ground the wheel spins freely. We only use the skiddy around the farm but boy she is so useful if you could help it would be appreciated. Carl
Sound like a broken drive chain.
if one wheel is not driving it leaves a couple of possible faults chain snapped axle sprocket spline stripped broken axle axle hub keyway stripped/broken or fallen out just need to determine where the break is
if the right rear is driving, and you dont hear any strange noises i'd suspect you have a broken sprocket. removed the front chaincase cover and take a look :drinkup
its the chain Well after some awesome advice and direction from guys on here we have identified it to be a chain. The rollers had collapsed and the sides slid in before snapping. Thank god it appears the sprockets are ok. I am going to change all 4 while I have the beast stripped down. My issue is how to get to the rear chains. There is a second case covering but half of it is under the main pump. Will I have to remove the whole pump or can I undo the front bolts and prop it up a bit to get the cover off and access. I have had a look into the back of the casing with a drain camera and appart from actually getting to the chains it looks semi easy to do. If I have to take pump off I assume it is disconnect all the hyd pipes and mounting bolts. Does it the slide out of the connection to the engine or is there something else we will have to do. Sorry, one more where is the chain casing drain plug? Found the front filler but buggered if I can find the drain. Once again, any advice would be really appreciated. Carl
What model bobcat is it. I haven't had too many of them apart but I have replaced chains on a 743. It is actually very simple to do if you have a 2 post car lift. Unhook the hoses from your drive motors then there should be 4 half inch bolts on each side of the frame behind the wheels and the whole chain drive falls out of the bottom. If I were you though while I had it out I would check all the axle bearings and seals while you were that far. They should be endless chains so no master link and the only way to get them on is to slide the axle shafts partially out, put your chain onto the sprocket and then slide the shift back into sprocket. Just looked back at the title face palm lol the procedure should be the same between the two machines Sent from my SAMSUNG-SGH-I317 using Tapatalk
Mate I have an 80's 643. Had a good look but cant find the bolts to drop chain casing. It looks like my wheel axles are bolted to the main body of the machine so cant see how the chain case would drop down? Also looks like the main body web plates are welded to the same chain casing. Any advice? Especially on how to get to rear sprockets to switch chains. Am I to take out axles and feed chains through?There isnt even an inspection plate at the back of the chain casing?
the easiest way to work on the rear chains is to remove the hydrostats. remove the hoses, tubelines, steering linkage and levers. may have to remove the front mount, (possibly have to remove the hyd pump to get the mount out of the way) remove the pump from the rear mount, or remove the mount, slide the pumps forward and lift them out while the pumps are out, now is the time to inspect and/or replace the ujoints & coupler. 643 chains used to have a cotter pin type master link, not sure if they are still available or if the replacement is a press together link. FWIW, i'd rather have a broken sprocket. :drinkup
Is this a straight 643? The only one I have ever worked on was a 743b but I didn't think there would be too many differences. On those though the chain case is black and the rest of the frame is white and where the 2 halves meet they are bolted together Sent from my SAMSUNG-SGH-I317 using Tapatalk