Scag Tiger Cub throwing the deck drive V belt

[Mad Mackie]

Hi Folks,
My 2008 Scag Tiger Cub with a V48 deck started throwing the deck drive V belt. I put the belt back around the tensioner pulley only to have it come off again in about an hour. With the deck drive belt off the deck pulleys, the tensioner arm had a lot of twisting movement. I removed the tensioner from the deck, pressed out the two bearings that allow the tensioner to turn and found the bearings to be badly worn. These bearings don't turn very much, but with the twisting affect, the balls in the bearings gouge deep spots into the inner and outer races. I replaced the bearings and also the two in the R/H spindle V belt tensioner and now all is back to normal. Machine has about 1,500 hours on it with a collection system installed and 2nd engine. This is a Briggs powered Tiger Cub.

 

[Dwellonroof]

I take it they are sealed bearings.?

 

[Mad Mackie]

Yes they are sealed bearings and there are two of them in each tension idler arm. Scag P/N 48224 which is a 99502H. These bearings are on all Velocity decks and may also be on older decks. These bearings don't turn very much during operation, but in time the balls make deep grooves in the outer and inner races and get sloppy causing the tension arms to sag allowing the idler pulleys to misalign. I was wondering why Scag decided to use ball bearings in this area, but I came to the conclusion that ball bearings were a better choice than metal bushings in this application having replaced the bushings on many other makes of decks much more often.

 

[jekjr]

They take a pounding in the tensioners. We have had to replace all of them on my Tiger Cat. Some of them more than once. it is a 2014 with about 2500 hours on it.

 

[Mad Mackie]

The drive v belt tensioner has the same bearings in it, I'm going to replace them and the drive v belt soon. I had replaced the pulleys a while back when I did the 2nd drive V belt change.