Bobcat 371 fluid change

[BobC]

Hi, I just got a Bobcat 371 for home use. The machine has a Kohler gas engine (14-16hp?) with a label saying 1987. I'm planning to use this machine to help do some backyard cleaning, grading, winter snow removal and perhaps build a garage. I like to first do some maintenance on this machine. I'm looking into buying a service manual. In the mean time, any help to my questions will be greatly appreciated. The previous owner (a demoliton company) said the machine was not used much and it has been siting for a couple of years. So, the gasoline in there is not good and it would be a good idea to drain it. However, the gas tank is below the engine and probably will take some works to get to. Any suggestion? I ask him about the hydraulic fluid. He said just use ATF. I browsed around this forum a bit and it seems that I should use 10w/30 or 10w/40 motor oil if not Bobcat Hydraulic oil. There some oil wetness at one or two hydraulic cylinders and a few drops of oil on the floor. I guess there's some oil leak at the seals. Do you think it might be partly due to the thinner ATF oil? From what I read, the transmission (chain case?) and hydraulic system share the same sump and fluid. Anybody know about how much oil I need to do a change? Didn't find a dip stick! Do I fill it up to the bottom of the filler neck? Any other suggestion? Thanks, Bob

 

[sterlclan]

is there a plug in the front of the case? if so fill untill it runs out of the plug like a truck/car rear axle as far as the seals thinner fluid would leak faster but a leak is a leak unless they are really bad you could run it and see if the seals swell any as far as the gas would a siphon hose get in the tank? I am not too familar with your machine so take it for what it is worth good luck and welcome to the fourm Jeff

 

[skidsteer.ca]

is there a plug in the front of the case? if so fill untill it runs out of the plug like a truck/car rear axle as far as the seals thinner fluid would leak faster but a leak is a leak unless they are really bad you could run it and see if the seals swell any as far as the gas would a siphon hose get in the tank? I am not too familar with your machine so take it for what it is worth good luck and welcome to the fourm Jeff

There should be a dipstick on the filler cap under the seat. Stick with atf oil in this unit, as it does not have a hydro drive but uses wet disc clutches for forward and reverse like your auto car tranny, so ATF is best. This oil also lubes 6 (i believe) chains and serves as a reservoir to your hyd pump. If you change it, have 7 or 8 gals on hand to refill, and a filter, this would be a good time to remove the cover the foot pedals are attached to and inspect the bottom of the chain case for problems (ie broken parts laying in there), wipe out the wear from the clutches, and ponder the thought it took to design that chain case. (made me dizzy just looking at it) Syphoned out the old gas if you can and fill with fresh stuff, unless you want to remove the engine and pull the fuel tank. (not all a bad idea as these little tin tanks are know to rust through and acummulate large quantities of rust inside) The hydraulic cylinders are easy to re seal (repack) and the seals are common and available from any hyd shop, as well as bobcat. Over all these are solid little machines that seem to hold their value well , despite lacking the variable speed of hydro drives. Make sure all the bolts through the boom and cylinder pins are tight so the wear is on the bushing and not the ears the bolt passes through. Be careful on hills as these unit are fully capable of freewheeling if you place the steering sticks in the center or neutral position. You probably don't want to know what the fastest speed one of these loader has attained, I'll bet it hurt. But used with this in mind, they are a good little loader. Regards Ken

 

[BobC]

There should be a dipstick on the filler cap under the seat. Stick with atf oil in this unit, as it does not have a hydro drive but uses wet disc clutches for forward and reverse like your auto car tranny, so ATF is best. This oil also lubes 6 (i believe) chains and serves as a reservoir to your hyd pump. If you change it, have 7 or 8 gals on hand to refill, and a filter, this would be a good time to remove the cover the foot pedals are attached to and inspect the bottom of the chain case for problems (ie broken parts laying in there), wipe out the wear from the clutches, and ponder the thought it took to design that chain case. (made me dizzy just looking at it) Syphoned out the old gas if you can and fill with fresh stuff, unless you want to remove the engine and pull the fuel tank. (not all a bad idea as these little tin tanks are know to rust through and acummulate large quantities of rust inside) The hydraulic cylinders are easy to re seal (repack) and the seals are common and available from any hyd shop, as well as bobcat. Over all these are solid little machines that seem to hold their value well , despite lacking the variable speed of hydro drives. Make sure all the bolts through the boom and cylinder pins are tight so the wear is on the bushing and not the ears the bolt passes through. Be careful on hills as these unit are fully capable of freewheeling if you place the steering sticks in the center or neutral position. You probably don't want to know what the fastest speed one of these loader has attained, I'll bet it hurt. But used with this in mind, they are a good little loader. Regards Ken

Thanks Jeff and Ken for the info! Jeff, I did find 2 plugs at the right side of the case between the front and rear wheels. It does look like the higher (about 1" higher) one is for checking level. I first open this one and no fluid came out. I then open the bottom one. I believe the lower one is for draining the fluid in the case. But I only got about 3/4 of a gallon of clean red ATF out. I guess there's still a bunch of fluid in the system such as the in pump, lines and cylinders. Ken, I found the filler cap under the seat but there is no dipstick. I guess the level is set by the higher plug at the side of the case. So I should use ATF (DEXON III?) for this machine! I haven't re-fill it yet. I'll look closer tomorrow to see whether I can open up the cover at the foot pedals. I saw the filter for the hydraulic. Do I need to use special filter? Will try to find a filter specified for this model but I'm just wondering whether a car engine filter would be OK! I found that at a couple cylinder to boom(?) linkages, the cylinder attachments can move from side to side. Perhaps they are missing some spacers or bushings. I'll see whether I can find some spacers (or cut some short sections of pipe to put in there to reduce the sideway movements. Thanks for the tips on how this machine behave. I saw that there are 2 pulleys on the motor and 2 pulleys on the case side. The PO said the drive belt can be moved to the outer pulley on the motor to make the machine go faster. But he said it was too fast when he tried it and he suggested to leave it the way it is now. I have changed the motor oil ealier today. It was the darkness and blackness motor oil I have ever seen! I have put back 2-1/4 quarts of 10w40 to get to the "F" mark on the dipstick. Somebody has put a little electric fuel pump on this machine to make fuel get to the carbureter easier. I replaced a rubber fuel hose but I should also replace the fuel filter - there are some dirt (rust I think) in the old filter. I pumped a little bit gas out with the electric pump but I get air in the line now. I will try to prime the line tomorrow and see whether I can pump more gas out. Thanks again, Bob.

 

[Tazza]

Thanks Jeff and Ken for the info! Jeff, I did find 2 plugs at the right side of the case between the front and rear wheels. It does look like the higher (about 1" higher) one is for checking level. I first open this one and no fluid came out. I then open the bottom one. I believe the lower one is for draining the fluid in the case. But I only got about 3/4 of a gallon of clean red ATF out. I guess there's still a bunch of fluid in the system such as the in pump, lines and cylinders. Ken, I found the filler cap under the seat but there is no dipstick. I guess the level is set by the higher plug at the side of the case. So I should use ATF (DEXON III?) for this machine! I haven't re-fill it yet. I'll look closer tomorrow to see whether I can open up the cover at the foot pedals. I saw the filter for the hydraulic. Do I need to use special filter? Will try to find a filter specified for this model but I'm just wondering whether a car engine filter would be OK! I found that at a couple cylinder to boom(?) linkages, the cylinder attachments can move from side to side. Perhaps they are missing some spacers or bushings. I'll see whether I can find some spacers (or cut some short sections of pipe to put in there to reduce the sideway movements. Thanks for the tips on how this machine behave. I saw that there are 2 pulleys on the motor and 2 pulleys on the case side. The PO said the drive belt can be moved to the outer pulley on the motor to make the machine go faster. But he said it was too fast when he tried it and he suggested to leave it the way it is now. I have changed the motor oil ealier today. It was the darkness and blackness motor oil I have ever seen! I have put back 2-1/4 quarts of 10w40 to get to the "F" mark on the dipstick. Somebody has put a little electric fuel pump on this machine to make fuel get to the carbureter easier. I replaced a rubber fuel hose but I should also replace the fuel filter - there are some dirt (rust I think) in the old filter. I pumped a little bit gas out with the electric pump but I get air in the line now. I will try to prime the line tomorrow and see whether I can pump more gas out. Thanks again, Bob.

The side to side movement you are talking about is normal, I am going to remove mine by maching some small nylon spacers, Nylon will not wear the side of the loader or the cylinder, so i do recommend you look at nylon before you go putting in metal spacers. Mine had worn so bad that the side of the cylinder has a nice flat face worn on it. On another machine i have, the cylinder wore so much that at the base of the ram and was actully leaking through the weld (well what little was left). If you do go the path of metal spacers, keep it greased and it will be fine, nylon seems to take lack of greasing a little better than steel on steel abrasion.
About the engine, its really sad just how many people neglect their engines, it doesn't cost much to drop the oil and change a filter. For a few dollars here and there it will save you thousnads later on from lack of lubrication because you never changed your oil.

 

[skidsteer.ca]

The side to side movement you are talking about is normal, I am going to remove mine by maching some small nylon spacers, Nylon will not wear the side of the loader or the cylinder, so i do recommend you look at nylon before you go putting in metal spacers. Mine had worn so bad that the side of the cylinder has a nice flat face worn on it. On another machine i have, the cylinder wore so much that at the base of the ram and was actully leaking through the weld (well what little was left). If you do go the path of metal spacers, keep it greased and it will be fine, nylon seems to take lack of greasing a little better than steel on steel abrasion.
About the engine, its really sad just how many people neglect their engines, it doesn't cost much to drop the oil and change a filter. For a few dollars here and there it will save you thousnads later on from lack of lubrication because you never changed your oil.

1/8 to 1/4" of sideways movement is pretty normal. Just be sure the bolt head and nut don't move in the loader arms when you lift and set the bucket back down. The bolt goes through a piece of pipe (bushing) and crushes the ears into the ends of the pipe. Making it all one solid piece. The cylinders goes around the pipe to provide a large wear surface. If the bolt loosens then the stress of the cylinder lift is just on the two 3/8" (or so) thick ears, instead of the whole width of the bushing. Look for a number on the hydraulic filter. Any good parts store can cross it for you, or go to Bobcat. There is probably 6 to 8" of oil in the chain case, so I doubt the lower plug is your drain. I not sure if dextron, or type f is the prefered fluid for these machines, as I never had a manual for mine either. Believe these were made from 1971 to 77. Mine was one of the early ones. Putting you belt over on the "High Range" pulleys will give you a top speed of about 5 mph instead of 2.5 No good for digging. but good for pushing snow. I had a set of chains for the back of mine and a 5' bucket for snow. Worked great. LOADER SPECIFICATIONS from Bobcat.com historical specs Model M-371 First Year of Production 1971 Last Year of Production 1977 Engine Model K321-S Engine Fuel Gasoline Engine Cooling Air Displacement 31.27 cubic in Horsepower 14 HP Number of Cylinders 1 Operating Weight 1900 lbs Rated Operating Capacity (SAE) 500 lbs Tipping Load 900 lbs Travel Speed - Low 2.5 mph Travel Speed - High 5 mph Pump Capacity 4.4 GPM Hydraulic Pump Pressure 1400 psi Length 92 in Width 36 in Height 72 in Height to Bucket Hinge Pin 89 in Dump Angle @ Maximum Height 37 deg Ground Clearance 4.75 in Angle of Departure 26 deg Rollback Angle 24 deg Wheelbase 28 in Wheel Tread n/a Vehicle Steering Dual Levers Hydraulic (Lift and Tilt) Dual Pedals Cylinders: Lift - Bore 2 in Cylinders: Lift - Rod 1 in Cylinders: Lift - Stroke 21.88 in Cylinders: Tilt - Bore 2 in Cylinders: Tilt - Rod 1 in Cylinders: Tilt - Stroke 14 in Tire Size 5.70x12 Auxiliary Hydraulics opt Operating Lights opt Parking Brake std BICS System (Interlock) n/a Regards Ken

 

[BobC]

1/8 to 1/4" of sideways movement is pretty normal. Just be sure the bolt head and nut don't move in the loader arms when you lift and set the bucket back down. The bolt goes through a piece of pipe (bushing) and crushes the ears into the ends of the pipe. Making it all one solid piece. The cylinders goes around the pipe to provide a large wear surface. If the bolt loosens then the stress of the cylinder lift is just on the two 3/8" (or so) thick ears, instead of the whole width of the bushing. Look for a number on the hydraulic filter. Any good parts store can cross it for you, or go to Bobcat. There is probably 6 to 8" of oil in the chain case, so I doubt the lower plug is your drain. I not sure if dextron, or type f is the prefered fluid for these machines, as I never had a manual for mine either. Believe these were made from 1971 to 77. Mine was one of the early ones. Putting you belt over on the "High Range" pulleys will give you a top speed of about 5 mph instead of 2.5 No good for digging. but good for pushing snow. I had a set of chains for the back of mine and a 5' bucket for snow. Worked great. LOADER SPECIFICATIONS from Bobcat.com historical specs Model M-371 First Year of Production 1971 Last Year of Production 1977 Engine Model K321-S Engine Fuel Gasoline Engine Cooling Air Displacement 31.27 cubic in Horsepower 14 HP Number of Cylinders 1 Operating Weight 1900 lbs Rated Operating Capacity (SAE) 500 lbs Tipping Load 900 lbs Travel Speed - Low 2.5 mph Travel Speed - High 5 mph Pump Capacity 4.4 GPM Hydraulic Pump Pressure 1400 psi Length 92 in Width 36 in Height 72 in Height to Bucket Hinge Pin 89 in Dump Angle @ Maximum Height 37 deg Ground Clearance 4.75 in Angle of Departure 26 deg Rollback Angle 24 deg Wheelbase 28 in Wheel Tread n/a Vehicle Steering Dual Levers Hydraulic (Lift and Tilt) Dual Pedals Cylinders: Lift - Bore 2 in Cylinders: Lift - Rod 1 in Cylinders: Lift - Stroke 21.88 in Cylinders: Tilt - Bore 2 in Cylinders: Tilt - Rod 1 in Cylinders: Tilt - Stroke 14 in Tire Size 5.70x12 Auxiliary Hydraulics opt Operating Lights opt Parking Brake std BICS System (Interlock) n/a Regards Ken

Perhaps a picture can explain better! The following picture shows the lift cylinder attachment point at the bucket. I have removed the bushing and am holding it (so I can take it the Bobcat store to get a replacment). There are almost 1" of spacing on each side. I believe this allows too much sideway movement and perhaps there were other parts (like spacers) there before. I am thinking of cutting some short sections of pipe and insert them on both sides of the cylinder attachment to reduce the sideway movements.

Here's a picture of the some bushings I took out:

One of the bushing at the bucket is damaged (as shown). The shorter bushing (rusty and need lubrication) is used on most of the other joints. I went to a local Bobcat dealer earlier today and try to get a couple replacement bushings. I was quoted ~$29 and ~$48 each for those bushings (ouch!) and they have to order them! Is there a more reasonable source for these replacement parts?
Here a picture of the two plugs (the two at the left) at the right side of the case. I fill the case with ATF up to the top plug. The Bobcat counter person seems to think ATF (or any hydraulic oil) is fine for my machine.

Ken, thanks for the tip of using the higher speed to push snow! But I guess I will stick with the slow speed until I get more experience with it! What kind of chain is good for snow? Do you use wire type chain on just the rear wheels? My 371 has a 42" bucket and I think it also has wider tires than standard model. The PO told me that the tires are filled with foam/rubber and they won't deflat. It seems to me this is a plus, yes?
Bob

 

[BobC]

Perhaps a picture can explain better! The following picture shows the lift cylinder attachment point at the bucket. I have removed the bushing and am holding it (so I can take it the Bobcat store to get a replacment). There are almost 1" of spacing on each side. I believe this allows too much sideway movement and perhaps there were other parts (like spacers) there before. I am thinking of cutting some short sections of pipe and insert them on both sides of the cylinder attachment to reduce the sideway movements.

Here's a picture of the some bushings I took out:

One of the bushing at the bucket is damaged (as shown). The shorter bushing (rusty and need lubrication) is used on most of the other joints. I went to a local Bobcat dealer earlier today and try to get a couple replacement bushings. I was quoted ~$29 and ~$48 each for those bushings (ouch!) and they have to order them! Is there a more reasonable source for these replacement parts?
Here a picture of the two plugs (the two at the left) at the right side of the case. I fill the case with ATF up to the top plug. The Bobcat counter person seems to think ATF (or any hydraulic oil) is fine for my machine.

Ken, thanks for the tip of using the higher speed to push snow! But I guess I will stick with the slow speed until I get more experience with it! What kind of chain is good for snow? Do you use wire type chain on just the rear wheels? My 371 has a 42" bucket and I think it also has wider tires than standard model. The PO told me that the tires are filled with foam/rubber and they won't deflat. It seems to me this is a plus, yes?
Bob

I just found some bushings and spacers here:
http://www.mfgsupply.com/m/c/AZ8358.html
http://www.mfgsupply.com/m/c/9-5707.html
Don't know how good they are! But probably ok for my small loader.
Bob

 

[Tazza]

Perhaps a picture can explain better! The following picture shows the lift cylinder attachment point at the bucket. I have removed the bushing and am holding it (so I can take it the Bobcat store to get a replacment). There are almost 1" of spacing on each side. I believe this allows too much sideway movement and perhaps there were other parts (like spacers) there before. I am thinking of cutting some short sections of pipe and insert them on both sides of the cylinder attachment to reduce the sideway movements.

Here's a picture of the some bushings I took out:

One of the bushing at the bucket is damaged (as shown). The shorter bushing (rusty and need lubrication) is used on most of the other joints. I went to a local Bobcat dealer earlier today and try to get a couple replacement bushings. I was quoted ~$29 and ~$48 each for those bushings (ouch!) and they have to order them! Is there a more reasonable source for these replacement parts?
Here a picture of the two plugs (the two at the left) at the right side of the case. I fill the case with ATF up to the top plug. The Bobcat counter person seems to think ATF (or any hydraulic oil) is fine for my machine.

Ken, thanks for the tip of using the higher speed to push snow! But I guess I will stick with the slow speed until I get more experience with it! What kind of chain is good for snow? Do you use wire type chain on just the rear wheels? My 371 has a 42" bucket and I think it also has wider tires than standard model. The PO told me that the tires are filled with foam/rubber and they won't deflat. It seems to me this is a plus, yes?
Bob

I would still like to see nylon bushings installed to take up that play, there is far too much there to leave. You will get dire in and cause wear with that much of a space.
As for pins, if you have access to a lathe you can easily make them yourself, and cheap!
Go to a specialist metal shop and ask for grade 4140 centreless ground bar (not peeled, you need the smooth finish), machine it to length and if needed, diameter (you should be able to get the correct diameter off them, so no machining needed) . Then take them to a heat treatment shop and get them to nitride them for you. Presto! cheap pins.
I am sending a box of pins and bushings to get done today. Its a full set thats about 10kg's worth, about 11 pins and 11 matching bushes. They want $55 to nitride tham, plus about $140 for the steel of which i have a fair amount left. Just a guide, i paid $25/metre for 1 1/4 and $30/metre for 1 1/2. If you want to replace all your pins, i really do recommend making your own pins and getting then nitrided. All these prices are in aussie $.
I hope this helps you out.

 

[skidsteer.ca]

I would still like to see nylon bushings installed to take up that play, there is far too much there to leave. You will get dire in and cause wear with that much of a space.
As for pins, if you have access to a lathe you can easily make them yourself, and cheap!
Go to a specialist metal shop and ask for grade 4140 centreless ground bar (not peeled, you need the smooth finish), machine it to length and if needed, diameter (you should be able to get the correct diameter off them, so no machining needed) . Then take them to a heat treatment shop and get them to nitride them for you. Presto! cheap pins.
I am sending a box of pins and bushings to get done today. Its a full set thats about 10kg's worth, about 11 pins and 11 matching bushes. They want $55 to nitride tham, plus about $140 for the steel of which i have a fair amount left. Just a guide, i paid $25/metre for 1 1/4 and $30/metre for 1 1/2. If you want to replace all your pins, i really do recommend making your own pins and getting then nitrided. All these prices are in aussie $.
I hope this helps you out.

Bob I just used a light duty set of chains for a pickup, and cut them down to fit. They were the chain type. The oil in your machine goes right to the bottom of the machine, So the plugs in your photo can't be the drain. Perhaps one is the level. Mine had a dipstick on the oil fill cap. Your foam filled tires are a bonus, no flats. And if the casings are still good when when they are wore down, I believe they can be re-capped and used again. My 773 has them but thay are alittle on the firm side. Your pins definitely have too much side play. If you use pipe to shim them up, use something with a thick wall (outside diameter is around 3/4" more then the inside diameter so the sides have a larger area to wear on. Be sure not to shim them too up tight and remove the "end crush" on the bushing. If I had kept mine I was toying with the idea of replacing the hi/ lo pulley arrangement with a CVT transmission from Comet. Then when you need more speed, just set the throttle higher. The "snowmobile transmission" would automatically down shift to a lower gear when the pushing got tough, and when the going was easy you could have more speed then you have in high. The ratio up shifts under light loads and higher rpm, and downshifts with low engine speed and heavy load. That would have made the 371 act alot like a new hydro drive loader. Ken