610 Bobcat Variable Sheave On Crankshaft

[bobcatman88]

Has anyone ever had a problem getting the variable sheave off the crankshaft. I put a bearing splitter on the sheave shaft and threaded in the two quarter inch bolts put the puller on and heated the shaft but it wont budge it just bends the quarter inch bolts. Anyone have any suggestions or recommended tools to use to get this thing pulled out. Also I broke off one bolt in the shaft now I need to get that out......I think my bearing splitter might have been to large and it was causing to pull on the outermost part of the bolts instead of in towards the shaft. Has anyone drilled these holes out bigger or is that a no no??

 

[Tazza]

Sadly i can't give you advise on how to get it off, as i have never done one but you are not alone. Many members in here that have worked on one of these has had issues getting it off too. Hopefully one of them will give you advise.
Can you drill the broken bolt out? Left handed drill bits work well for this. Drill a pilot hole and go up, some times it will pick up and un-screw for you.

 

[6brnorma]

Bobcat……I have always worried about the possibility of breaking one or both of those small bolts. It would definitely be best if you could "easy out" the broken bolt. If you try to drill 'oversize' you will hit the crank immediately so I would use a counter clock bit to start a pilot hole for the easy out, hoping it would back out with just the bit. I'm going to ask a couple of questions…..don't be offended. First, you did remove the crank retaining bolt inside the sheave before you tried to pull the sheave? and secondly….when you put in the two small bolts, they were short enough so they "shouldered" up snug against the sheave but don't hit the crank acting as a set screw? I have probably removed a couple hundred of those sheaves in my life using this method…..with some heat on the sheave and then a good smack or two with a rubber mallet, I have never had to do anything more…..it just pops right off. If you have done all those things my next move would be to get some Kroil or another penetrating oil in there to help. Don't break that sheave……it's cast and expensive. Also….when you get back to the point of trying to pull the sheave…..use grade 5 or better bolts in the side of the sheave and be sure they are short enough to not hit the crank and yet shoulder up to the sheave. Feel free to ask questions…..lets get this bugger fixed.

 

[bobcatman88]

Bobcat……I have always worried about the possibility of breaking one or both of those small bolts. It would definitely be best if you could "easy out" the broken bolt. If you try to drill 'oversize' you will hit the crank immediately so I would use a counter clock bit to start a pilot hole for the easy out, hoping it would back out with just the bit. I'm going to ask a couple of questions…..don't be offended. First, you did remove the crank retaining bolt inside the sheave before you tried to pull the sheave? and secondly….when you put in the two small bolts, they were short enough so they "shouldered" up snug against the sheave but don't hit the crank acting as a set screw? I have probably removed a couple hundred of those sheaves in my life using this method…..with some heat on the sheave and then a good smack or two with a rubber mallet, I have never had to do anything more…..it just pops right off. If you have done all those things my next move would be to get some Kroil or another penetrating oil in there to help. Don't break that sheave……it's cast and expensive. Also….when you get back to the point of trying to pull the sheave…..use grade 5 or better bolts in the side of the sheave and be sure they are short enough to not hit the crank and yet shoulder up to the sheave. Feel free to ask questions…..lets get this bugger fixed.

Thanks!! I'm not offended at all I always want to make sure I'm not forgetting something obvious. Ok so I used grade 8 bolts and I tightened them down until they bottomed out and then backed them out a couple turns. But I think you answered my problem I think I'm using two long of bolts so the head is not flush with the sheave they are sticking out about a half inch so when I go to use the puller it bends them over. And yes I did take the bolt out of the crankshaft I can see in to the keyway. I think my problem is my puller was not getting tight and just bending the bolts so with the head flush that makes since that they would not shear off and give you some nice tension. May I ask what puller and splitter you use because I might want to get one of these. This is the last step I have to go to get the engine removed for rebuild! I have everything else disconnected. Thanks again for all this helpful advice should have been on this forum a lot sooner.

 

[6brnorma]

Thanks!! I'm not offended at all I always want to make sure I'm not forgetting something obvious. Ok so I used grade 8 bolts and I tightened them down until they bottomed out and then backed them out a couple turns. But I think you answered my problem I think I'm using two long of bolts so the head is not flush with the sheave they are sticking out about a half inch so when I go to use the puller it bends them over. And yes I did take the bolt out of the crankshaft I can see in to the keyway. I think my problem is my puller was not getting tight and just bending the bolts so with the head flush that makes since that they would not shear off and give you some nice tension. May I ask what puller and splitter you use because I might want to get one of these. This is the last step I have to go to get the engine removed for rebuild! I have everything else disconnected. Thanks again for all this helpful advice should have been on this forum a lot sooner.

88……I'm a Snap On snob……since I don't know what I'm doing most of the time, I figured I should look good doing it So I don't recommend buying these tools but rather so you have a reference. I use Snap On bar puller #CJ84C and SnapOn separator #CJ951….that will give you an idea what to look for……you can probably find them at Harbor Freight for one tenth the price. You will have to find a couple of long bolts to finish making up the puller. So here's my procedure…….I pull the crank retaining bolt & washer, replace the bolt ONLY and snug it up (don't want to damage the threads in the crank with the puller)……put in the two small bolts as described earlier, then set up the puller with the pressure screw resting on top of the crank bolt that you replaced. Put as much pressure as you feel comfortable with, without breaking either of the two smaller bolts……then apply heat to the base of the sheave…..when you feel you've applied plenty of heat, smack it on the end with a mallet. My experience has been that about half come off with just the puller, the other half need heat and the mallet……I have never had to go beyond that. A word of warning…..do not allow anyone to stand directly in front of the sheave when you smack it…….I've had parts go flying every which way when it all comes loose.

 

[bobcatman88]

88……I'm a Snap On snob……since I don't know what I'm doing most of the time, I figured I should look good doing it So I don't recommend buying these tools but rather so you have a reference. I use Snap On bar puller #CJ84C and SnapOn separator #CJ951….that will give you an idea what to look for……you can probably find them at Harbor Freight for one tenth the price. You will have to find a couple of long bolts to finish making up the puller. So here's my procedure…….I pull the crank retaining bolt & washer, replace the bolt ONLY and snug it up (don't want to damage the threads in the crank with the puller)……put in the two small bolts as described earlier, then set up the puller with the pressure screw resting on top of the crank bolt that you replaced. Put as much pressure as you feel comfortable with, without breaking either of the two smaller bolts……then apply heat to the base of the sheave…..when you feel you've applied plenty of heat, smack it on the end with a mallet. My experience has been that about half come off with just the puller, the other half need heat and the mallet……I have never had to go beyond that. A word of warning…..do not allow anyone to stand directly in front of the sheave when you smack it…….I've had parts go flying every which way when it all comes loose.

Hey thanks for the tool part numbers and advice that was really helpful!! Went and bought a similar puller at harbor freight had to add a couple longer bolts to get the separator to separate a little farther. I got the grade 8 bolt drilled out.......(mushroomed the hole a little and made it to big so will have to have that fixed maybe tap it out a size bigger...). But anyways I just set the bolt in the hole and used shorter ones like you said used the new puller and the impact and heard a big snap and the thing flew right off towards me... but is stood to the side like you said. Now I have the engine out and its off to get a rebuild. Thanks for all the help!! Be good to get the thing up and running again such a useful machine. Does anyone know anywhere that rebuilds Wisconsin engines in the Minnesota/Wisconsin Area?

 

[OldMachinist]

Hey thanks for the tool part numbers and advice that was really helpful!! Went and bought a similar puller at harbor freight had to add a couple longer bolts to get the separator to separate a little farther. I got the grade 8 bolt drilled out.......(mushroomed the hole a little and made it to big so will have to have that fixed maybe tap it out a size bigger...). But anyways I just set the bolt in the hole and used shorter ones like you said used the new puller and the impact and heard a big snap and the thing flew right off towards me... but is stood to the side like you said. Now I have the engine out and its off to get a rebuild. Thanks for all the help!! Be good to get the thing up and running again such a useful machine. Does anyone know anywhere that rebuilds Wisconsin engines in the Minnesota/Wisconsin Area?

St Paul, MN
http://industrialenginerebuilders.com/

Green bay WS
http://www.barilengine.com/

 

[6brnorma]

Hey thanks for the tool part numbers and advice that was really helpful!! Went and bought a similar puller at harbor freight had to add a couple longer bolts to get the separator to separate a little farther. I got the grade 8 bolt drilled out.......(mushroomed the hole a little and made it to big so will have to have that fixed maybe tap it out a size bigger...). But anyways I just set the bolt in the hole and used shorter ones like you said used the new puller and the impact and heard a big snap and the thing flew right off towards me... but is stood to the side like you said. Now I have the engine out and its off to get a rebuild. Thanks for all the help!! Be good to get the thing up and running again such a useful machine. Does anyone know anywhere that rebuilds Wisconsin engines in the Minnesota/Wisconsin Area?

Glad I could help. There are several things I would make sure are correct while I was this deep into the machine. Just a few…….check to make sure the bushings in the 'jackshaft' sheave are in good working order, if not, now is the time to rebuild it (there are three pen bushings and two main bushings)…..absolutely do not overlook this one. Also, clutch linings (4), hydro filter, alt. belt and main drive belt for starters.

 

[gearbox]

Glad I could help. There are several things I would make sure are correct while I was this deep into the machine. Just a few…….check to make sure the bushings in the 'jackshaft' sheave are in good working order, if not, now is the time to rebuild it (there are three pen bushings and two main bushings)…..absolutely do not overlook this one. Also, clutch linings (4), hydro filter, alt. belt and main drive belt for starters.

If you change the hydraulic filter [ under floor boards ] raise the front wheels as high as you can [ car ramps ] then you can change the filter . and not leak much oil . if you open the can while sitting flat you better have a sack of floor dry handy ask me how I know . also when you get the filter it does not come with the big O ring . order one and replace it . Gearbox

 

[bobcatman88]

Glad I could help. There are several things I would make sure are correct while I was this deep into the machine. Just a few…….check to make sure the bushings in the 'jackshaft' sheave are in good working order, if not, now is the time to rebuild it (there are three pen bushings and two main bushings)…..absolutely do not overlook this one. Also, clutch linings (4), hydro filter, alt. belt and main drive belt for starters.

Ok Thanks, I was planning on a new belt it needs one and I was planning on changing the filter since its easy to get at. Also I am putting a new alternator belt on while I am that far. Going to do a nice look over to make sure everything that could be fixed easily while the engine is out gets fixed. Lots of nice room to work with now.......