Bobcat 610 belt deflection?

[Unicam]

ok thank you. in my haste, i turned the wrong one, the threaded nut one, compressing the spring on the other part, the one with the push-rod going thru it. i'm sorry i don't know the right names. I'm d-ripping with sweat grease and bug bites, I'll have to try it tomorrow after work. thank you for your help

I put a shin under the Allen. No dice. The sheave slams shut faster ( often killing the engine) but releases just as fast when the lever is released. The mechanic at my work apparently put an o ring kit in the valve for the guy I bought it from thinking that would fix it. I guess he sold it to me when it didn't. Something is not holding the pressure and since it's not leaking I have to think it's in the valve. I've been trying to find out info on the thermal relief, maybe it's open. I don't know.

 

[6brnorma]

I put a shin under the Allen. No dice. The sheave slams shut faster ( often killing the engine) but releases just as fast when the lever is released. The mechanic at my work apparently put an o ring kit in the valve for the guy I bought it from thinking that would fix it. I guess he sold it to me when it didn't. Something is not holding the pressure and since it's not leaking I have to think it's in the valve. I've been trying to find out info on the thermal relief, maybe it's open. I don't know.

I would pull the valve and rebuild it or have it done by a shop that knows what they're doing. If you do it, it's literally a $25.00 fix or $100.00 or so at a shop. Now….. spool or valve body corrosion would be a different story.

 

[Unicam]

I put a shin under the Allen. No dice. The sheave slams shut faster ( often killing the engine) but releases just as fast when the lever is released. The mechanic at my work apparently put an o ring kit in the valve for the guy I bought it from thinking that would fix it. I guess he sold it to me when it didn't. Something is not holding the pressure and since it's not leaking I have to think it's in the valve. I've been trying to find out info on the thermal relief, maybe it's open. I don't know.

an update for the hecks of it... after i put a shim under the allen i think i hurt my roto swivel asm. as it's leaving a oil ring around the sheave hole and dripping a little. i'm sure it's my fault as i saw it was closing as if it had too much pressure but i probably did it 10-15 times anyway hoping the sheave would stay closed. I had an idea to remove the shim and back the allen out as to reduce the pressure to the sheave. This way i could bungee the lever all the way forward but only partially close the sheave. It did seem to work but The problem still exists when i try to turn, even on grass the belt stops and i lose power to the wheels. it does seem to go forward and backwards ok but not great. It's weak enough that i'm apprehensive to drive it down a slight grade to my back yard. I have only 1 acre and got the machine in hopes of doing some very light work. maybe i'll try to deglaze the sheave or ruff up the belt in an attempt to keep it from slipping.? would belt dressing help me at all?

 

[Unicam]

an update for the hecks of it... after i put a shim under the allen i think i hurt my roto swivel asm. as it's leaving a oil ring around the sheave hole and dripping a little. i'm sure it's my fault as i saw it was closing as if it had too much pressure but i probably did it 10-15 times anyway hoping the sheave would stay closed. I had an idea to remove the shim and back the allen out as to reduce the pressure to the sheave. This way i could bungee the lever all the way forward but only partially close the sheave. It did seem to work but The problem still exists when i try to turn, even on grass the belt stops and i lose power to the wheels. it does seem to go forward and backwards ok but not great. It's weak enough that i'm apprehensive to drive it down a slight grade to my back yard. I have only 1 acre and got the machine in hopes of doing some very light work. maybe i'll try to deglaze the sheave or ruff up the belt in an attempt to keep it from slipping.? would belt dressing help me at all?

thinking out loud here.. and maybe someone can let me know about the thermal relief rod movement. Mine comes out as soon as the engine fires up. the "manual" says "plunger must not move in valve body when belt is in high variable speed position with full engine rpm." From that vague description i'm thinking it should always be in. looking at the schematic, when the rod comes out, i'm assuming the ball comes off the seat. I tried to hold it in with large channel lock to test it, I thought i was but the sheave still wasn't holding. quite possible i wasn't holding it in all the way. even with the nut/spring cranked all the way tight it still comes out at start-up. the manual also states if you run out of threads to put a washer under the nut but i can crank it till the spring bottoms with no change so not sure what a washer would do. maybe missing the ball or something, who knows. I know it was suggested to go thru the valve already, i'm just hypothesizing)

 

[Unicam]

thinking out loud here.. and maybe someone can let me know about the thermal relief rod movement. Mine comes out as soon as the engine fires up. the "manual" says "plunger must not move in valve body when belt is in high variable speed position with full engine rpm." From that vague description i'm thinking it should always be in. looking at the schematic, when the rod comes out, i'm assuming the ball comes off the seat. I tried to hold it in with large channel lock to test it, I thought i was but the sheave still wasn't holding. quite possible i wasn't holding it in all the way. even with the nut/spring cranked all the way tight it still comes out at start-up. the manual also states if you run out of threads to put a washer under the nut but i can crank it till the spring bottoms with no change so not sure what a washer would do. maybe missing the ball or something, who knows. I know it was suggested to go thru the valve already, i'm just hypothesizing)

ok, moving forward, baby steps. I went off my last hunch and disassembled the thermal relief rod asm on the speed valve. upon removal I got the guide out, then the spring... no ball. I was half relieved I may have found the problem and have bummed as i'd never find the right ball seeing as i thought it was missing. a few seconds of digging with a magnet and out comes the ball! It had been assembled incorrectly according to the manual someone put the ball going in first ( it needs to seat against the guide). I carefully inspected the o-rings, cleaned it spotless and reinstalled it according to the manual. BAM, nothing happened when i moved the lever forward, no movement from the sheave at all. I was about to drag it out to the curb with a free sign on it when i realized i had not only removed the shim i had placed under the allen, but backed it off considerably. I cranked the allen all the way in and..... and.... and... it works, lol. It's weak, ( needs a shim under the allen, lmao) but it seems to work! now i only tried it for a few seconds and i think i hurt my actuator as i am getting some oil leakage from around the swivel asm but it seems to work. I'm very relieved as to the progress, it's been a challenge. I talked to the mechanic who installed o-rings "in" the valve he says he never removed the thermal relief rod. well whatever, someone installed it incorrectly and it possibly goes back a couple owners as the guy i bought it from said it never worked right since he got it and he had given up and sold it to me. One reason i'm sharing my experience is to possibly help a nubee like myself. I couldn't find much if any info on the subject on this thermal relief asm. probably due to the fact there is very little to go wrong in there. maybe extremely rare to have a small chunk of debris in the seat but basically the only real issue is if it was put together wrong. worth checking nonetheless. I'll go back out and put a shim back under the allen and see it i get full actuation, fingers crossed.

 

[6brnorma]

thinking out loud here.. and maybe someone can let me know about the thermal relief rod movement. Mine comes out as soon as the engine fires up. the "manual" says "plunger must not move in valve body when belt is in high variable speed position with full engine rpm." From that vague description i'm thinking it should always be in. looking at the schematic, when the rod comes out, i'm assuming the ball comes off the seat. I tried to hold it in with large channel lock to test it, I thought i was but the sheave still wasn't holding. quite possible i wasn't holding it in all the way. even with the nut/spring cranked all the way tight it still comes out at start-up. the manual also states if you run out of threads to put a washer under the nut but i can crank it till the spring bottoms with no change so not sure what a washer would do. maybe missing the ball or something, who knows. I know it was suggested to go thru the valve already, i'm just hypothesizing)

Danny has some pics on his thread that are very useful and I added some comments there for rebuilding the valve. I believe your roto-swivel assembly was probably leaking long before you added a shim. You can rebuild that assembly for not too much of an expense……follow the manual and there are a number of threads in this forum that pertain to this procedure. Belt dressing is not the answer.

 

[Unicam]

Thank you for your help (so far, I know i'll need more). next item is probably get it charging, oh I forgot, it wants to vapor lock, that's probably next item. . this thing is a real can of worms . I just got done adding the same shim back in under the allen and I graded my parking spot gravel, machine seems to work awesome, just like I knew it could even turned around on ruff concrete! This machine has so much potential and i've wanted one for so many years, i'm very fortunate to have gotten it. I can't figure out how to post pictures but i did get it as far as uploaded to the sight. it won't let me type when i select html.... dunno. if you go to photos my album is called bobcat 610. it has a blue 4 wheeler in the background. anyways, thanks for your help so far.

 

[6brnorma]

Thank you for your help (so far, I know i'll need more). next item is probably get it charging, oh I forgot, it wants to vapor lock, that's probably next item. . this thing is a real can of worms . I just got done adding the same shim back in under the allen and I graded my parking spot gravel, machine seems to work awesome, just like I knew it could even turned around on ruff concrete! This machine has so much potential and i've wanted one for so many years, i'm very fortunate to have gotten it. I can't figure out how to post pictures but i did get it as far as uploaded to the sight. it won't let me type when i select html.... dunno. if you go to photos my album is called bobcat 610. it has a blue 4 wheeler in the background. anyways, thanks for your help so far.

https://www.amazon.com/Carter-P60504--Line-Electric-Fuel/dp/B000BZX92K/ref=sr_1_1?ie=UTF8&qid=1468173899&sr=8-1&keywords=carter+p60504
Answer to your vapor lock problem…..along with rubber fuel line hose……mount it on the side of the machine not the engine. You'll need to cut and paste the link.

 

[Bpu699]

https://www.amazon.com/Carter-P60504--Line-Electric-Fuel/dp/B000BZX92K/ref=sr_1_1?ie=UTF8&qid=1468173899&sr=8-1&keywords=carter+p60504
Answer to your vapor lock problem…..along with rubber fuel line hose……mount it on the side of the machine not the engine. You'll need to cut and paste the link.

Bringing an old thread back from the dead... my bobcat 610 restoration moves on... Rebuilt the variable speed sheave... no leaks! Yea! Moving the lever forward does nothing. Hooked up a pressure guage and valve works. 0 psi up to 60 psi... but 60 psi isn't doing anything. Google suggests that required pressure to work the variable speed sheave is 400 psi??? Is that correct??? Also, which Allen key spring do you shim? There one facing forward and one facing inward, I think... Thanks.

 

[6brnorma]

Bringing an old thread back from the dead... my bobcat 610 restoration moves on... Rebuilt the variable speed sheave... no leaks! Yea! Moving the lever forward does nothing. Hooked up a pressure guage and valve works. 0 psi up to 60 psi... but 60 psi isn't doing anything. Google suggests that required pressure to work the variable speed sheave is 400 psi??? Is that correct??? Also, which Allen key spring do you shim? There one facing forward and one facing inward, I think... Thanks.

400 psi … MAX…. the shims and adjustment is the forward facing plug.

 

[Bpu699]

400 psi … MAX…. the shims and adjustment is the forward facing plug.

Thanks! Any idea why the current PSI is so low? Is 60 PSI supposed to do the job?

 

[6brnorma]

Thanks! Any idea why the current PSI is so low? Is 60 PSI supposed to do the job?

I don't believe 60psi is enough but I'm no hydraulics expert. If you will go to a site on facebook…. Melroe Bobcat Owners of America….. there are a number of very knowledge folks there that have experience with the 600 series bobcats. Good luck.

 

[Bpu699]

I don't believe 60psi is enough but I'm no hydraulics expert. If you will go to a site on facebook…. Melroe Bobcat Owners of America….. there are a number of very knowledge folks there that have experience with the 600 series bobcats. Good luck.

Will do, thanks!