# Cant tighten new belt on a vintage 917.255521



## Geoff813 (May 17, 2018)

The tractor has been running fine for a few decades now. The engine was replaced about 15 years ago with a 15 hp B&S OHV and a well used replacement deck two years ago; the old one rotted away. I did all the side to side and front to rear adjustments back then

The old belt wore out and I had to by a genuine Sears locally which is too loose in the correct lower hole in the rock shaft assembly, the blades barely turn. The belt is the 106085X.

It appears that the complete deck has to be moved back. OR is there a slightly shorter belt that will seat in the pulleys well? The original is a 79".

Any ideas?

Geoff


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## sixbales (May 18, 2011)

Howdy Geoff, welcome to the forum.

Are your spindle bearings and idler bearings tight, or do they have some play in them? How about the idler arm bushing? I would first make sure that all bearings are tight with no play. 

Can you make a new anchor for the belt tensioning spring to increase stretch by about an inch? 

A NAPA auto shop can get you a belt just about any length you want, but my luck with changing belt lengths has not been good.


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## Geoff813 (May 17, 2018)

Thanks for the reply

The spindles are fairly new, tight and regularly lubed, and the idler assembly is fine also.

Ive thought about making up a new anchor point for the spring as belt life has always been poor on this and my other similar tractor. BUT Im mowing a bit over an acre plus several trails to the back of 5 acres where I pull tree branches. 
OTOH there is no play in the clutch lever and the tension at the top is very tight; it almost seems like Im missing something and at 77 that isnt impossible

Could it be possible that all 38" decks are not the same?

Geoff


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## mastrkee (May 8, 2017)

Have you measured the new belt to insure that you have the correct length belt. Another thing, as you mentioned the deck difference, the pullies could be smaller. Is there any chance you could measure the old ones?


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## wjjones (May 28, 2010)

Do you grease the belt tensioner pivot point? They get all rusted, and debris in there which will keep it from keeping the belt all the way tight. I do know craftsman never riggs them right to begin with even the new mowers have to much slack on the deck belt, and drive belt.


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## Geoff813 (May 17, 2018)

Pivot is well lubed, spindles turn free, spindle brakes are pulled back plus the belt guides are moved in as far as they go before hitting the spindles and that tightens the belt a little but not enough. It mows OK on short grass but not the jungle which has formed the past week in some places....even on the highest height setting.

Today I'll roughen up all the pulleys and maybe add another guide on the deck to tighten the belt. I remember having to do that years ago on another deck. 

Ive heard that belt dressing is no good?????


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## Geoff813 (May 17, 2018)

Success of sorts as I finally remembered something I did about 20 years ago when I first started playing with these Sears 80's era tractors found in the junk pile at the local transfer station. Usually it was a simple electrical problem that took 15 minutes to fix (Mostly just bypassing a nanny state switch/sensor) Others were dirty carbs or frozen deck spindles.

Anyway I remembered that I had problems with new Sears belts back then and nothing appeared amiss. What I wound up doing then and today is to remove the outboard bolt from the idler bracket, cut the bracket height down an inch with the Sawzall, and install a 5/16 bolt with a clean shank of sufficient length, place a nut on top and another on the bottom with a flat washer and lock washer. I backed off the spindle guides a bit which now leaves me with 4 adjustments as the belt wears before having to go to the top hole in the rock shaft.

That works just fine and i finished my first of the year mowing.

Thanks for all the help.

I'll probably be back again as I transplant a frozen up transaxle from a serious oil burning 12 HP Tecumseh OHV into another one that I'd already replaced the blown B&S 12.5 hp flathead with a 2 cylinder 16 hp flatty a few years ago. Leave it to Sears to not provide an accessible lube point in their transaxles.

Geoff


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