JD drive belt

[jfal]

I have 2001 JD LT155 lawn tractor with 42" mulching deck. I replaced the drive belt routing atound all guides & pulleys. When I fully depress the brake pedal the drive belt slips off the rear pulley. If I slightly depress the brake I can successfully engage the drive. Any suggestions as to cause and solution?

 

[beenthere]

Welcome to TBN

Something bent and out of line, or ??

JD oem belt? M126009

 

[Spanner]

I suspect you've either mis-routed or are missing the shaped wire belt guide which fits across the rear of the chassis and over the transmission pulley.

Part No. M147132

Item #4:

https://partscatalog.deere.com/jdrc/sidebyside/equipment/66977/referrer/navigation/pgId/80686474

 

[Richard001]

I suspect you've either mis-routed or are missing the shaped wire belt guide which fits across the rear of the chassis and over the transmission pulley.

Part No. M147132

Item #4:

https://partscatalog.deere.com/jdrc/sidebyside/equipment/66977/referrer/navigation/pgId/80686474

Or item 17 -Belt Drive Guide

 

[Richard001]

Transmission	Tuff-Torq K51
Type	belt-driven hydrostatic
Gears	infinite forward and reverse
Oil change	sealed unit, owner service is not recommended
Hydrostatic transmission with two right-side foot pedals and right-side brake. Free-wheeling lever at rear of tractor.

Well I missed this at first. This tractor has a hydrostatic transmission, depressing the brake pedal should NOT affect the drive belt tension.

I would guess that the drive belt tension spring is not connected to the correct location on the frame.

Richard

 

[Spanner]

Or item 17 -Belt Drive Guide

No.#17 is the guide for the deck belt on the front (Crankshaft) pulley.
There are two versions depending on deck width and these are noted in the Parts List.

OP says his issue is with Transmission belt coming off at the Rear pulley.

 

[Spanner]

Well I missed this at first. This tractor has a hydrostatic transmission, depressing the brake pedal should NOT affect the drive belt tension.

I would guess that the drive belt tension spring is not connected to the correct location on the frame.

Richard

On this model (and LT166) The plate carrying the two tensioning idlers pivots when the Brake Pedal is depressed, causing the drive to release when the brake is applied.

Heavier brake pedal double-spring over-rides the lighter belt tension spring.

 

[Richard001]

On this model (and LT166) The plate carrying the two tensioning idlers pivots when the Brake Pedal is depressed, causing the drive to release when the brake is applied.

Heavier brake pedal double-spring over-rides the lighter belt tension spring.

Wow, so this is some sort of safety mechanism I guess. Seems like a dumb idea, but I guess one has to live with it.

 

[big bubba]

as a footnote, a worn idler pulley will throw belts in operation. check yours for play. unfortunately i have yet to find an idler pulley w/grease zerk good luck