Chain case oil 733G

[Feedbag]

Hello, I recently bought a 2003 773G and I am changing the fluids in it. My parts and service manuals have not arrived yet in the mail. Question – I want to change the chain case oil in the machine. I read that it takes 9 gallons of motor oil. I live in New England and was going to use 20W50 conventional motor oil, no synthetic, no diesel engine oil, just regular old conventional motor oil... Will this be Ok? Thanks.....

 

[bobbie-g]

The chain case just provides an oil bath that the chains/sprockets run in. Nothing fancy there at all. The conventional wisdom on the forum here is that having most any old oil in the chain case will do fine. Tazza recommends draining then sopping up the gunk in the bottom of the chain case with rags. I haven't gone to that length yet I drain the chain case every thousand hours, then connect a hydraulic hose to the output connector on the lift arms (lower, I think) and turn on the flow with the other end of the hose poked into the fill port on the front of the machine. Stop when it starts sputtering. Note: some folks say this isn't a good idea, to run the hyd pump like that. I'm careful to stop immediately when it sputters, and I believe that's a safe thing to do, but do what you wish. So that puts the used hydraulic oil in the chain case, then I top off with the cheapest Walmart oil I can buy. But I do always run Bobcat hyd fluid in the hyd system. That's a long answer to your question. Shorter answer: Yes, I think 20W50 would be fine. And don't forget to change out the case drain filters. Holler if you don't know what/where those are. ---Bobbie-G

 

[Feedbag]

The chain case just provides an oil bath that the chains/sprockets run in. Nothing fancy there at all. The conventional wisdom on the forum here is that having most any old oil in the chain case will do fine. Tazza recommends draining then sopping up the gunk in the bottom of the chain case with rags. I haven't gone to that length yet I drain the chain case every thousand hours, then connect a hydraulic hose to the output connector on the lift arms (lower, I think) and turn on the flow with the other end of the hose poked into the fill port on the front of the machine. Stop when it starts sputtering. Note: some folks say this isn't a good idea, to run the hyd pump like that. I'm careful to stop immediately when it sputters, and I believe that's a safe thing to do, but do what you wish. So that puts the used hydraulic oil in the chain case, then I top off with the cheapest Walmart oil I can buy. But I do always run Bobcat hyd fluid in the hyd system. That's a long answer to your question. Shorter answer: Yes, I think 20W50 would be fine. And don't forget to change out the case drain filters. Holler if you don't know what/where those are. ---Bobbie-G

Wow, thanks for all the info !! I do not know where the case drain filters are at this point, anxiously waiting for my manuals to arrive......

 

[bobbie-g]

Wow, thanks for all the info !! I do not know where the case drain filters are at this point, anxiously waiting for my manuals to arrive......

I'll check my 763 tmro, it'll be a bit different than your G, but close enuf. Check back here.

 

[bobbie-g]

I'll check my 763 tmro, it'll be a bit different than your G, but close enuf. Check back here.

The 773G that I've worked on isn't nearby, so can't check locations for the two case drain filters. On my 763, one is connected directly to the lower side of the hyd oil reservoir; the other is connected between the hyd pump and one of the drive motors. You didn't list an email adr in your profile so I can't send a pix or two. Best way to find them: look for an unpainted aluminum cylinder about 1-1/2" dia and 3" long (Tazza can provide metric equiv ). Half inch hose on either end. The top screws off, revealing a spring and a bronze metallic filter. Note the orientation. I always replace the filters with new elements from Bobcat, but I suspect they would clean up fine with carb cleaner. You'll prob want to renew the orings too. I have a spare filter housing, so when I do the change, I have a refurbished housing with new filter in my hand to install when I take the old one loose. Less messy. Good luck! ---Bobbie-G

 

[Tazza]

The 773G that I've worked on isn't nearby, so can't check locations for the two case drain filters. On my 763, one is connected directly to the lower side of the hyd oil reservoir; the other is connected between the hyd pump and one of the drive motors. You didn't list an email adr in your profile so I can't send a pix or two. Best way to find them: look for an unpainted aluminum cylinder about 1-1/2" dia and 3" long (Tazza can provide metric equiv ). Half inch hose on either end. The top screws off, revealing a spring and a bronze metallic filter. Note the orientation. I always replace the filters with new elements from Bobcat, but I suspect they would clean up fine with carb cleaner. You'll prob want to renew the orings too. I have a spare filter housing, so when I do the change, I have a refurbished housing with new filter in my hand to install when I take the old one loose. Less messy. Good luck! ---Bobbie-G

That is an excellent way of recycling your old oil, the chain case can use just about any engine or hydraulic oil. The chains, sprockets and bearings are not moving very fast, so i see no issues.

 

[Feedbag]

The 773G that I've worked on isn't nearby, so can't check locations for the two case drain filters. On my 763, one is connected directly to the lower side of the hyd oil reservoir; the other is connected between the hyd pump and one of the drive motors. You didn't list an email adr in your profile so I can't send a pix or two. Best way to find them: look for an unpainted aluminum cylinder about 1-1/2" dia and 3" long (Tazza can provide metric equiv ). Half inch hose on either end. The top screws off, revealing a spring and a bronze metallic filter. Note the orientation. I always replace the filters with new elements from Bobcat, but I suspect they would clean up fine with carb cleaner. You'll prob want to renew the orings too. I have a spare filter housing, so when I do the change, I have a refurbished housing with new filter in my hand to install when I take the old one loose. Less messy. Good luck! ---Bobbie-G

Thanks Bobbie -G, I'll take a look for them... I just found that the automatic belt tensioner for the cooling fan belt is seized... Will disassemble tomorrow and get that straightened out, got a new belt for it, discovered the problem when I went to install it.....

 

[bobbie-g]

Thanks Bobbie -G, I'll take a look for them... I just found that the automatic belt tensioner for the cooling fan belt is seized... Will disassemble tomorrow and get that straightened out, got a new belt for it, discovered the problem when I went to install it.....

The tensioner for the cooling fan gearbox is a bit complex. I think it takes a 5/16" hex bit to loosen the securing bolt. The Big Boys tell me the spring should be replaced every 1000 hrs or so, since they sometimes lose tension, allow the belt to slip, and overheat the engine. Sales pitch? I dunno, I replace mine. There is also a bearing, a couple of o rings, some funny washers, and maybe a nylon bushing in there somewhere, I forget the details. Also, make sure the idler pulley bearing is OK. Those are all small parts in a dirty environment, so I replace most everything each 1000 hrs. I greatly prefer to work on machines on my schedule in my shop, rather than in the middle of a job in the middle of a field.

 

[Feedbag]

The tensioner for the cooling fan gearbox is a bit complex. I think it takes a 5/16" hex bit to loosen the securing bolt. The Big Boys tell me the spring should be replaced every 1000 hrs or so, since they sometimes lose tension, allow the belt to slip, and overheat the engine. Sales pitch? I dunno, I replace mine. There is also a bearing, a couple of o rings, some funny washers, and maybe a nylon bushing in there somewhere, I forget the details. Also, make sure the idler pulley bearing is OK. Those are all small parts in a dirty environment, so I replace most everything each 1000 hrs. I greatly prefer to work on machines on my schedule in my shop, rather than in the middle of a job in the middle of a field.

On my 773, I freed up the automatic belt tensioner for the cooling fan belt. I installed a new belt from Bobcat that is the correct belt for the machine. However, the new belt seems a little loose compared to what I am used to. There is plenty of cooling air coming out of the vents when running, but I'm just not used to a belt being that loose. Is it designed to run this way? There is nothing in the service manual (that I can find) that addresses this subject... Thanks....

 

[bobbie-g]

On my 773, I freed up the automatic belt tensioner for the cooling fan belt. I installed a new belt from Bobcat that is the correct belt for the machine. However, the new belt seems a little loose compared to what I am used to. There is plenty of cooling air coming out of the vents when running, but I'm just not used to a belt being that loose. Is it designed to run this way? There is nothing in the service manual (that I can find) that addresses this subject... Thanks....

I think the belts on my 763 and 863 also feel like they're not as tight as they could be. I think that may be the nature of the beast. ---Bobbie-G

 

[Feedbag]

I think the belts on my 763 and 863 also feel like they're not as tight as they could be. I think that may be the nature of the beast. ---Bobbie-G

Ok, Thank You !!!