Bobcat 440, I actually made a fix that worked!

Bret4207

Well-known Member
For years I've had problems with the variable speed pulley vibrating on my ancient Bobcat 440. It was the same with the original Onan and the new repower Briggs. Obviously the brass inner sleeve was worn, probably from some PO running it loose. I tried several ways of fixing it. Finally I decided that my only options were having a new inner sleeve machined or finding a way to center the assy on the shaft. 3 set screws, equidistant apart, as far out on the shaft as I could get them made all the difference in the world! It's reduced the vibration from me worrying it'd shake the bearings out of the engine to just a slight wobble. The shale was so bad before it broke the exhaust manifold from the weight of the muffler, and it was getting worse. It would move enough that the set screw holding the pulley on the shaft would loosen up in a matter of minutes causing the pulley to walk and ruining a $100.00 drive belt. Not anymore! Don't know why I didn't think of this before.

I'll never get my money back out of this skid steer, but it's the perfect size for my low ceiling barn.
 
Here I thought that I had an old one, a model 444; also with the Onan Engine!
It is currently not running, have had other projects to work on. But glad to see I'm not the only one who likes the older models. I think it is just as legitimate as a '60's classic tractor.
What are you using for a battery? Hard to find the 'Corvair' battery any more.
 

Huh, don't know why I wrote 440, mines a 444 too! I'm not sure on the battery. There are 2 or 3 that rotate among the Bobcat, Simplicity mowers and a JD40c. IIRC it's narrow and a "NF" type. I can try to remember to look. I know I made risers for the seat out of 2x4 to clear the terminals.

If you ever go to repower the 444 I can give you the basics you need to do. Got my engine from Small Engine Warehouse. I think it's for the 500, had to remove some adapters they make from the crank and build a new mounting plate, but it works lots better than the Onan. Lining the darn thing up takes more time than anything else.
 
I"ve got a old 444 also. Some previous owner repowered it with a Kohler. The issue I have is that the set screws for the variable pulley don"t seem to hold well. Every once in awhile when hydraulic pressure is applied to the variable speed cylinder it pushes the cylinder off the shaft, which then bends up or breaks the rotating fitting on the end of the cylinder, and they are not cheap. Did you have this problem and did your three new set screws help or solve this?

Without going into a long story about the backyard repower the PO did and all the misalignments which have beat the heck out of the crank and thrust bearings in the engine (I"ve fixed these issues), I"m probably looking at a new engine in the future. Have you been happy with the Briggs? Any particular reason you decided on the Briggs and not the Kohler (I see Small Engine Warehouse offers both for the 500).

I"m like you, I don"t have much invested in the machine, but it works.
 
I went with the Briggs they offered for the 500 IIRC, not because it was a Briggs or Kohler but because that's all they offered at the time. I've had equally bad luck with modern Kohlers as with modern Briggs. The Briggs is a commercial unit and I sure hope it does better than their consumer line for $2200.00! Of course half that price is SEW's crank and fittings, R+D, etc.

The VSP should be in 2 pieces. The moving pulley does not, or at least should not, ever be able to cause the fixed pulley to move. I think probably you have an alignment issue. Check the other pulley, the driven pulley under the seat and make sure it's opening and closing. If it's stuck or hasn't been greased and you use the variable speed selector you're altering the alignment. The other thing is the fixed half of the VSP moving by itself. If the set screws aren't holding then you need to investigate why. Mine has either 2 or 3 set screws- 1 on the key way and another that butts up against the brass inner sleeve. I have no idea if that is factory or not. It's not a big deal to add additional set screws and if you go through the inner sleeve you gain a lot of thread area. If the fixed half has any play when the screws are tightened down then yes, the screws at the end of the crank will help. Check and see if your set screws are stripped at all too. And check your alignment
again too. If the belt is running cockeyed you will have problems. I spent several hours figuring alignment out and still am not sure I have it 100%. Opposite halves of the pulleys move when you apply the VSP- the left half on the VSP and right half on the driven pulley. Makes it fun getting it right. You also want to check your crank for play and that inner sleeve for wear. Mine is belled out pretty good and needs replacing to work right without the set screws.
 

Noting you have a 444. Just purchased one. Where can I get a drive belt? Also, bucket is sluggish - oil seems up - can't seem to find a resevoir. heavier weight, possible water or is the pump crapping out?

Dennis
 

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