610 Drive Sheave problems

[jeffscoggins]

After less than three hours of use after buying my 610 the drive sheave suddenly came off the crankshaft. It has a Honda engine in it and so there is no book that explains how to go about reattaching it. I've tried a number of things. It seems to be held on the shaft by nothing but two set screws which only tighten against the shaft. That just doesn't seem right. I can't get the set screws tight enough to keep it from sliding off the crankshaft within seconds. Does anyone have any experience with a set up like this?

 

[skidsteer.ca]

Is the belt alignment straight so as to prevent a sideways pull?
Also could you drill a small hole in the crank where the set screws go?
Take a look at the factory manual and see how it was originally fastened.
Ken

 

[jeffscoggins]

Is the belt alignment straight so as to prevent a sideways pull?
Also could you drill a small hole in the crank where the set screws go?
Take a look at the factory manual and see how it was originally fastened.
Ken

I've considered the drilling idea but that scares me. I don't know that I have it aligned correctly because there are all sorts of spacers in it that I have no idea where the go. I have lined up a straight edge along the two sheaves though and they are close. With the Wisconsin engine it's supposed to bolt to the end of the crankshaft. The Honda engine has threads to accept a bolt but unless it got lost when it came apart the first time it doesn't seem to have that. I've wondered if I could add one but don't know enough about how it works to know if I can do that. Jeff

 

[6brnorma]

Is the belt alignment straight so as to prevent a sideways pull?
Also could you drill a small hole in the crank where the set screws go?
Take a look at the factory manual and see how it was originally fastened.
Ken

Assuming you are using the factory sheave designed for the wisconsin engine.....those are NOT set screws designed to hold the sheave onto the shaft. They are holes designed to assist in pulling the sheave only and will have no bolts in place when the sheave is properly installed and operating. Correct installation is with a bolt inside the sheave that passes through the end of the sheave directly into the end of the crankshaft. Yours is the first I have heard of with a Honda engine installed. Most 610s came with a vh4d wisconsin engine and would have a short tapered crank end to mount the sheave. There were a much smaller number that came with diesel engines and I believe the Petter had a straight shaft so you might have a sheave designed for that. In order to help you, we need to know if you are using a factory sheave, is it designed to fit a tapered or straight shaft or is it some other sheave maybe from Honda.

 

[jeffscoggins]

Assuming you are using the factory sheave designed for the wisconsin engine.....those are NOT set screws designed to hold the sheave onto the shaft. They are holes designed to assist in pulling the sheave only and will have no bolts in place when the sheave is properly installed and operating. Correct installation is with a bolt inside the sheave that passes through the end of the sheave directly into the end of the crankshaft. Yours is the first I have heard of with a Honda engine installed. Most 610s came with a vh4d wisconsin engine and would have a short tapered crank end to mount the sheave. There were a much smaller number that came with diesel engines and I believe the Petter had a straight shaft so you might have a sheave designed for that. In order to help you, we need to know if you are using a factory sheave, is it designed to fit a tapered or straight shaft or is it some other sheave maybe from Honda.

Someone converted it from a Wisconsin to a Honda engine. I will see if I can research the drive sheave and find out if it's original. It looks just like the one in the manual, and it has obvious had some conversion done to it. For instance, there is a 1/8" thick brass sleeve inside to make it fit the Honda crankshaft. That sleeve has been drilled out to allow the set screws to go through it. If the holes were only for pulling then that means they were threaded in the conversion and perhaps were meant mostly to hold the brass sleeve in place. Maybe there was an end bolt that was lost when it all came apart. Is it possible to post pictures here?

 

[skidsteer.ca]

Someone converted it from a Wisconsin to a Honda engine. I will see if I can research the drive sheave and find out if it's original. It looks just like the one in the manual, and it has obvious had some conversion done to it. For instance, there is a 1/8" thick brass sleeve inside to make it fit the Honda crankshaft. That sleeve has been drilled out to allow the set screws to go through it. If the holes were only for pulling then that means they were threaded in the conversion and perhaps were meant mostly to hold the brass sleeve in place. Maybe there was an end bolt that was lost when it all came apart. Is it possible to post pictures here?

Pictures have to be uploaded to photobucket or other online hosting site then open the picture, (not a link to the picture, but the actual photo) copy it and paste it here.
More info in the faq section of the forum near the top
Ken

 

[6brnorma]

Someone converted it from a Wisconsin to a Honda engine. I will see if I can research the drive sheave and find out if it's original. It looks just like the one in the manual, and it has obvious had some conversion done to it. For instance, there is a 1/8" thick brass sleeve inside to make it fit the Honda crankshaft. That sleeve has been drilled out to allow the set screws to go through it. If the holes were only for pulling then that means they were threaded in the conversion and perhaps were meant mostly to hold the brass sleeve in place. Maybe there was an end bolt that was lost when it all came apart. Is it possible to post pictures here?

Jeff, I can help with standard but I'm not very good with 'conversions' so there are some very knowledgable folks on here that will be more help. A couple of things...it is important that the sheave be rock solid and balanced for several reasons. An out of balance sheave (sheaves are matched, balanced and marked) will eat up the crank itself in pretty short order, a sheave, improperly aligned and out of balance will likewise shorten belt life considerably (half an hour in some cases), not to mention the potential hazard to the operator when a sheave comes off the shaft. You're going to need to post pics.

 

[jeffscoggins]

Jeff, I can help with standard but I'm not very good with 'conversions' so there are some very knowledgable folks on here that will be more help. A couple of things...it is important that the sheave be rock solid and balanced for several reasons. An out of balance sheave (sheaves are matched, balanced and marked) will eat up the crank itself in pretty short order, a sheave, improperly aligned and out of balance will likewise shorten belt life considerably (half an hour in some cases), not to mention the potential hazard to the operator when a sheave comes off the shaft. You're going to need to post pics.

Here's what it looks like before tackling it.

Here the outter half is off.

Here you can see the set screws.

This is a closeup of the crankshaft. It's a little buggered up, but not too bad.

Here's a wide shot of the crankshaft. There are threads in the end.

It's a Honda engine.

Here's the inside of the fixed part of the sheave. You can see the brass sleeve that has been fitted inside.

The set screws go through the brass sleeve.

The silver in the back is the back of the roto-swivel. I haven't had to remove it. The whole thing just slides off. There might be room in there to put a bold into the end of the shaft with a washer up against the brass sleeve.

 

[6brnorma]

Here's what it looks like before tackling it.


Here the outter half is off.


Here you can see the set screws.


This is a closeup of the crankshaft. It's a little buggered up, but not too bad.


Here's a wide shot of the crankshaft. There are threads in the end.


It's a Honda engine.


Here's the inside of the fixed part of the sheave. You can see the brass sleeve that has been fitted inside.

The set screws go through the brass sleeve.


The silver in the back is the back of the roto-swivel. I haven't had to remove it. The whole thing just slides off. There might be room in there to put a bold into the end of the shaft with a washer up against the brass sleeve.

Good....the pictures are very useful. That is a bobcat sheave off of one of the diesels with the straight shaft. My guess would be that they had it bolted into the shaft and used the shims to adjust it's position due to the Honda shaft being slightly different then original equipment. One reason I say that is I see what appears to be some damage to the roto-swivel assembly where the bolt would be located. The set screws would then have been used to stabilize the sheave. If you are able to bolt it in and have it correctly aligned, I like Skidsteers idea of drilling slightly into the shaft to help the set screws but more knowledgable folk should advise you on that. I'm curious about two things.....is there an opposing hole to one of the set screw holes and is the cut out in the body of the bobcat at the other end of this engine round or square?

 

[7LBSSMALLIE]

Good....the pictures are very useful. That is a bobcat sheave off of one of the diesels with the straight shaft. My guess would be that they had it bolted into the shaft and used the shims to adjust it's position due to the Honda shaft being slightly different then original equipment. One reason I say that is I see what appears to be some damage to the roto-swivel assembly where the bolt would be located. The set screws would then have been used to stabilize the sheave. If you are able to bolt it in and have it correctly aligned, I like Skidsteers idea of drilling slightly into the shaft to help the set screws but more knowledgable folk should advise you on that. I'm curious about two things.....is there an opposing hole to one of the set screw holes and is the cut out in the body of the bobcat at the other end of this engine round or square?

please keep us posted as to how this works out eng spec# and family, this may be a viable alterantive.

 

[6brnorma]

please keep us posted as to how this works out eng spec# and family, this may be a viable alterantive.

How are they driving the Hydraulic pump?

 

[jeffscoggins]

Good....the pictures are very useful. That is a bobcat sheave off of one of the diesels with the straight shaft. My guess would be that they had it bolted into the shaft and used the shims to adjust it's position due to the Honda shaft being slightly different then original equipment. One reason I say that is I see what appears to be some damage to the roto-swivel assembly where the bolt would be located. The set screws would then have been used to stabilize the sheave. If you are able to bolt it in and have it correctly aligned, I like Skidsteers idea of drilling slightly into the shaft to help the set screws but more knowledgable folk should advise you on that. I'm curious about two things.....is there an opposing hole to one of the set screw holes and is the cut out in the body of the bobcat at the other end of this engine round or square?

I noticed the damage too, but have not been able to find a bolt anywhere in the vicinity of where it came off. There is not an opposing hole for either of the set screws and the cut out in the body of the bobcat is round. I have purchased a bolt that I believe has the correct threads. Tomorrow I will try to see if that does the trick.

 

[jeffscoggins]

I noticed the damage too, but have not been able to find a bolt anywhere in the vicinity of where it came off. There is not an opposing hole for either of the set screws and the cut out in the body of the bobcat is round. I have purchased a bolt that I believe has the correct threads. Tomorrow I will try to see if that does the trick.

I'm having a lot of trouble posting to this thread now. Keeps giving me errors.

 

[jeffscoggins]

I'm having a lot of trouble posting to this thread now. Keeps giving me errors.

It looks like I'm only having trouble replying to two of the replies above, so I'll just answer them in a reply to myself. Hydraulic pump is driven by another shaft out the opposite side of the engine. A large on about 3 inches diameter. The owners manual is for a Honda GX610, 620, 670. I'll see if I can figure which on it is.

 

[jeffscoggins]

Good....the pictures are very useful. That is a bobcat sheave off of one of the diesels with the straight shaft. My guess would be that they had it bolted into the shaft and used the shims to adjust it's position due to the Honda shaft being slightly different then original equipment. One reason I say that is I see what appears to be some damage to the roto-swivel assembly where the bolt would be located. The set screws would then have been used to stabilize the sheave. If you are able to bolt it in and have it correctly aligned, I like Skidsteers idea of drilling slightly into the shaft to help the set screws but more knowledgable folk should advise you on that. I'm curious about two things.....is there an opposing hole to one of the set screw holes and is the cut out in the body of the bobcat at the other end of this engine round or square?

All right, here's where things are. I found a bolt that would fit the shaft and bolted the sheave to the shaft. It's not as tight as it should be on the shaft, so I used the set screws to try to balance it and it worked fairly well for a while. It has loosened up again, however. It doesn't seem to be working it's way off the shaft, at least. So hopefully I can continue to adjust the set screws and get it into balance.

 

[6brnorma]

All right, here's where things are. I found a bolt that would fit the shaft and bolted the sheave to the shaft. It's not as tight as it should be on the shaft, so I used the set screws to try to balance it and it worked fairly well for a while. It has loosened up again, however. It doesn't seem to be working it's way off the shaft, at least. So hopefully I can continue to adjust the set screws and get it into balance.

We really need someone with experience with the straight shafts on 610s. On the taper shafts, you would use a bolt with a heavy washer that would shoulder up on a portion of the sheave in order to hold it in place. Pure speculation on my part but I would guess something of that nature would have been designed for the straight shaft. Do you have a key to accommodate the bushing used?

 

[jeffscoggins]

We really need someone with experience with the straight shafts on 610s. On the taper shafts, you would use a bolt with a heavy washer that would shoulder up on a portion of the sheave in order to hold it in place. Pure speculation on my part but I would guess something of that nature would have been designed for the straight shaft. Do you have a key to accommodate the bushing used?

Yes, the key does fit the bushing. I think it was custom made since the shaft and sheave required different widths. Your speculation about something designed to lock it onto the straight shaft makes sense. I'll try Googling around just to see if I can come up with anything.

 

[Tazza]

Yes, the key does fit the bushing. I think it was custom made since the shaft and sheave required different widths. Your speculation about something designed to lock it onto the straight shaft makes sense. I'll try Googling around just to see if I can come up with anything.

Did you try loctite on the set screw threads? Hopefully it will prevent them backing off and coming loose again.

 

[jeffscoggins]

Did you try loctite on the set screw threads? Hopefully it will prevent them backing off and coming loose again.

Yes, I used loctite. I'm not even sure it's a problem with them backing off so much as the different pieces moving around just a little.