Drive motor, purchase new or rebuild?

[la350]

I'm hoping to pull the left side drive motor off this weekend. Looking at the parts list in the service manual, it appears there is a rebuild kit available? Has anyone done this rebuild? Is a shade tree mech able to do this or do I have to take it to a shop. If no rebuild kit, who has the cheapest prices on a new motor? Thanks Lance mid/late '80's 843

 

[Tazza]

Are you sure its the motor and not the pump?
It depends on what is worn as to the value in repair/replace. If its just s seal, its cheap, if the groler is damaged its not cheap, same with the drive "dog bone" as some call it.
I would confirm it is actually the motor at fault first, then work from there.

 

[la350]

Are you sure its the motor and not the pump?
It depends on what is worn as to the value in repair/replace. If its just s seal, its cheap, if the groler is damaged its not cheap, same with the drive "dog bone" as some call it.
I would confirm it is actually the motor at fault first, then work from there.

the right side works fine (makes nice tight "donuts" on the ground since all I have is right stick!). I have been hearing an "impact wrench" type noise from the left side for a while now with no noise from the right side. I'm trying to work all the bugs out of the 843 before shipping it to Alaska for my commercial fishing operation so I don't mind pulling the motor and checking it out. Thanks Lance

 

[Tazza]

the right side works fine (makes nice tight "donuts" on the ground since all I have is right stick!). I have been hearing an "impact wrench" type noise from the left side for a while now with no noise from the right side. I'm trying to work all the bugs out of the 843 before shipping it to Alaska for my commercial fishing operation so I don't mind pulling the motor and checking it out. Thanks Lance

That noise sounds like a chain or sprocket is skipping.... It wouldn't hurt to pull the motor and inspect it for damage or wear. I would also check the drive line too, see if the sprockets are good and not slipping. Also check the reduction box if it has one fited, not sure if the 843s had it or not.

 

[la350]

That noise sounds like a chain or sprocket is skipping.... It wouldn't hurt to pull the motor and inspect it for damage or wear. I would also check the drive line too, see if the sprockets are good and not slipping. Also check the reduction box if it has one fited, not sure if the 843s had it or not.

Ok, how do I access the chain/sprockets? I suppose there is an access cover somewhere? It did not make noise when going forward (which it wont do now, no movement at all from left side) but only when moving the left stick fore/aft with the right stick in the centered position. Thats what made me think it was the pump............

 

[skidsteer.ca]

Ok, how do I access the chain/sprockets? I suppose there is an access cover somewhere? It did not make noise when going forward (which it wont do now, no movement at all from left side) but only when moving the left stick fore/aft with the right stick in the centered position. Thats what made me think it was the pump............

Lift the cab and under the seat area in the center belly is a retangular box running fore and aft. Your wheel motors bolt to the side of it. Remove the large square covers from the top side to gain access to the chain case.
Ken

 

[Tazza]

Lift the cab and under the seat area in the center belly is a retangular box running fore and aft. Your wheel motors bolt to the side of it. Remove the large square covers from the top side to gain access to the chain case.
Ken

I can't remember what type of motor your machine has. But i remember another member about 2 years back with the same sort of noise, his turned out th be a bad piston in the motor. But that was a piston motor, not geroler style. Im not sure if yours is a geroler style or piston.... If the chains and sprockets look ok, its time to check the motor.

 

[jjb16033]

I can't remember what type of motor your machine has. But i remember another member about 2 years back with the same sort of noise, his turned out th be a bad piston in the motor. But that was a piston motor, not geroler style. Im not sure if yours is a geroler style or piston.... If the chains and sprockets look ok, its time to check the motor.

I just had my 843B apart and had to replace the axle bearings and the bearings in both gear boxes were bad. It made some noise but i do think the noise you are describing is the chain slipping over the spocket. Lift the cab and there is a rectangular cover plate to get access to the chains. There are actually two plates but you can only take the front one off and the rear one will not come out unless you remove the pumps.

 

[jmatt20]

I just had my 843B apart and had to replace the axle bearings and the bearings in both gear boxes were bad. It made some noise but i do think the noise you are describing is the chain slipping over the spocket. Lift the cab and there is a rectangular cover plate to get access to the chains. There are actually two plates but you can only take the front one off and the rear one will not come out unless you remove the pumps.

i had a 1983 843 and it had geroler motors , they are re-buildable , the key is CLEAN workplace. the bad news is ...if it's not a problem with your chains and sprockets,you most likely need more than just a motor rebuild . the pump /motor hydro circuit is semi closed ..the same fluid moves back and forth as you drive forwards and backwards only a small amount is exchanged to the reservoir thru the case drain line on the motor. if you have significant damage to your motor the ground up metal parts have gone to your rotating group in the pump...the pump is very sensitive to contamination . i had a drive problem, i put the machine on the trailer, 300 ft. and then unloaded it at the shop another 50 ft. when i broke it down the rotating group was destroyed, the little pistons were flopping around in over-sized holes. with the hrs on my machine i opted for rebuilt motors and pump unit complete ..total cost about 5000$us. that's not a dealer price ...haha i called around to hydraulic suppliers ...as soon as i gave him my part numbers he said ..oh you have a 843 bobcat we have the complete set up for you ,,and so he did....

 

[la350]

i had a 1983 843 and it had geroler motors , they are re-buildable , the key is CLEAN workplace. the bad news is ...if it's not a problem with your chains and sprockets,you most likely need more than just a motor rebuild . the pump /motor hydro circuit is semi closed ..the same fluid moves back and forth as you drive forwards and backwards only a small amount is exchanged to the reservoir thru the case drain line on the motor. if you have significant damage to your motor the ground up metal parts have gone to your rotating group in the pump...the pump is very sensitive to contamination . i had a drive problem, i put the machine on the trailer, 300 ft. and then unloaded it at the shop another 50 ft. when i broke it down the rotating group was destroyed, the little pistons were flopping around in over-sized holes. with the hrs on my machine i opted for rebuilt motors and pump unit complete ..total cost about 5000$us. that's not a dealer price ...haha i called around to hydraulic suppliers ...as soon as i gave him my part numbers he said ..oh you have a 843 bobcat we have the complete set up for you ,,and so he did....

Ok, so it sounds as if purging the hyd system would be the thing to do. Can someone explain that proceedure for me. thanks!