Looking to buy a Bobcat 743 that has drive issues

[gatorguy]

Sorry, I'm late to the party on this one, she is one of the first models of 743. See the square block on the hydraulic pump, left side there are 3 hoses going into the block, remove the middle hose and fitting, there is a bronze screen behind it. It's almost always missed and causes drive issues.
The motor blow-by could be wear, generally if it's really bad, people just swap it for a V2203 out of a refrigeration unit.

Ok, so after installing a new 40 micron filter ($28), spin on, putting new hydraulic oil in the resoivoir and getting the steering levers centering spring on. (still creeps but atleast they center) I took it for a test drive. At full throttle it went 5 mph tops according to a gps app which seems way too slow...especially for snow clearing. Maybe just with the different sized tires fighting each other causing it to go slower? Anyway...so it will do a 360 when moving to the left(right forward, left reverse), but when going hard right (left forward, right reverse) it will click/pop, whatever you want to call it. At first i wondered if it was a refief valve but then the thought occured it could be a chain slipping... Any insight on how those sprockets from the picture look? I cant find a picture of a new one to compare it to. Also, is the plug on the front of the case the fill level plug? If so that appears to be below the axles so not sure how they get bathed. And its 3 inches to the bottom, so 3"x9"x49" chaincase is 6 gallons not the 9 gallons it calls for... Anyway, I dumped more used oil into it and found a leaky axle seal. So I popped the Gear pump and after making a axle puller, got all four out, sprockets and chains. Question - do the chains just ride on those metal guides? My chains have a lot of slop...they actually wore into those housings off the reduction gearboxes! So i obviously need a new chain, just not sure on the sprockets. Any other recommendations while im this far in? Reduction gearboxes? I checked the bearing side to side before dissasembling and they had no play. For a chain, if i buy locally is a masterlink ok or does it need to be continuous? Thanks in advance! Ill post pics of the carnage tomorrow

 

[6620]

Ok, so after installing a new 40 micron filter ($28), spin on, putting new hydraulic oil in the resoivoir and getting the steering levers centering spring on. (still creeps but atleast they center) I took it for a test drive. At full throttle it went 5 mph tops according to a gps app which seems way too slow...especially for snow clearing. Maybe just with the different sized tires fighting each other causing it to go slower? Anyway...so it will do a 360 when moving to the left(right forward, left reverse), but when going hard right (left forward, right reverse) it will click/pop, whatever you want to call it. At first i wondered if it was a refief valve but then the thought occured it could be a chain slipping... Any insight on how those sprockets from the picture look? I cant find a picture of a new one to compare it to. Also, is the plug on the front of the case the fill level plug? If so that appears to be below the axles so not sure how they get bathed. And its 3 inches to the bottom, so 3"x9"x49" chaincase is 6 gallons not the 9 gallons it calls for... Anyway, I dumped more used oil into it and found a leaky axle seal. So I popped the Gear pump and after making a axle puller, got all four out, sprockets and chains. Question - do the chains just ride on those metal guides? My chains have a lot of slop...they actually wore into those housings off the reduction gearboxes! So i obviously need a new chain, just not sure on the sprockets. Any other recommendations while im this far in? Reduction gearboxes? I checked the bearing side to side before dissasembling and they had no play. For a chain, if i buy locally is a masterlink ok or does it need to be continuous? Thanks in advance! Ill post pics of the carnage tomorrow

Oh the suspense, So what happened next? Do you know what year your bobcat is?

 

[gatorguy]

Oh the suspense, So what happened next? Do you know what year your bobcat is?

Haha, I wasnt sure if anyone was even reading it...sorry for th elate reply last week was crazy busy as we had a snowstorm blow through. Unfortunately the 743 was still apart so had to rent a very nice 2 speed kubota with an enclosed cab...after the rental bill on that though, im looking forward to having my own machine doing the work although it will take a lot longer. So anyway, I found out that the "metal chain guides" I was reffering too have been since replaced by some plastic ones. In the parts catalog they reference them . It makes sense because the metal ones clearly weren't working. So I ordered timken bearings, national seals, bobcat wear rings, the new style chain guides off ebay, a seat, a couple tilt cylinder pins, etc. All is here now, and ready for installation. Im planning on using my old sprockets and chains maybe puting a half link in or something. My chains have an 1/8" stretch over two feet so doesent seem too bad to me but hopefully someone has some better insight. My two hardlines that run along the floor behind the blowerhousing were definitely not looking good, but i capped an and and applied compressed air, but failed to find a leak. Got my hydraulics shop to chop the 12" off them that was corroded, and add in a new piece so i should be good for another 40 years! However I am now really trying to find out where the oil is coming from...rearmain on the motor looks good, im pretty sure the hardlines were fine, the seal on the gearpump doesent look bad so perhalps the oil cooler but i pressurized it with compressed air and got nothing either. It has oil stuck all over it and so does the blower fins so oil is coming out of somewhere and the blower is just whipping it everywhere. Checked the glowplugs and they seem fine, replaced the v belt so the motor is ready to go back in. Could do an oil change now but id prefer to have the oil warmed up for a better drain out. So to directly answer your question, No I dont know the specific year, but based on having the bronze filter in the port block, along with the old style chain guides I would conclude it was from the first 5 years of production. 1980 - 1985?

 

[Tazza]

Haha, I wasnt sure if anyone was even reading it...sorry for th elate reply last week was crazy busy as we had a snowstorm blow through. Unfortunately the 743 was still apart so had to rent a very nice 2 speed kubota with an enclosed cab...after the rental bill on that though, im looking forward to having my own machine doing the work although it will take a lot longer. So anyway, I found out that the "metal chain guides" I was reffering too have been since replaced by some plastic ones. In the parts catalog they reference them . It makes sense because the metal ones clearly weren't working. So I ordered timken bearings, national seals, bobcat wear rings, the new style chain guides off ebay, a seat, a couple tilt cylinder pins, etc. All is here now, and ready for installation. Im planning on using my old sprockets and chains maybe puting a half link in or something. My chains have an 1/8" stretch over two feet so doesent seem too bad to me but hopefully someone has some better insight. My two hardlines that run along the floor behind the blowerhousing were definitely not looking good, but i capped an and and applied compressed air, but failed to find a leak. Got my hydraulics shop to chop the 12" off them that was corroded, and add in a new piece so i should be good for another 40 years! However I am now really trying to find out where the oil is coming from...rearmain on the motor looks good, im pretty sure the hardlines were fine, the seal on the gearpump doesent look bad so perhalps the oil cooler but i pressurized it with compressed air and got nothing either. It has oil stuck all over it and so does the blower fins so oil is coming out of somewhere and the blower is just whipping it everywhere. Checked the glowplugs and they seem fine, replaced the v belt so the motor is ready to go back in. Could do an oil change now but id prefer to have the oil warmed up for a better drain out. So to directly answer your question, No I dont know the specific year, but based on having the bronze filter in the port block, along with the old style chain guides I would conclude it was from the first 5 years of production. 1980 - 1985?

Oil can come out of the rear seal on the drive pump where the motor connects to it.
There is a hose that has a U shape to it from the bottom on the control block that is prone to failure. Access is only there when the motor is out, it's not fun at all.

 

[6620]

Oil can come out of the rear seal on the drive pump where the motor connects to it.
There is a hose that has a U shape to it from the bottom on the control block that is prone to failure. Access is only there when the motor is out, it's not fun at all.

Interesting, keep us posted on the parts hanging!

 

[gatorguy]

Oil can come out of the rear seal on the drive pump where the motor connects to it.
There is a hose that has a U shape to it from the bottom on the control block that is prone to failure. Access is only there when the motor is out, it's not fun at all.

Just to make sure we are talking about the same thing...its the two hardliners that run along the floor behind the engine? Pic attached.

https://drive.google.com/file/d/1BxFMyF8Lwa8ts04JFkxjqUCJOP7QOQAD/view?usp=drivesdk

I did get the shop to replace the corroded part but I couldn't see any leaks in them.