OT - lawn tractor drive

[ScoutB]

I just bought a 2004 Huskee Supreme (MTD) 25HP 50" cut tractor for a song because the PO didn't want to mess with the leaky crankcase gasket. Other than the leak the tractor worked just fine. I put a new gasket in over the weekend and replaced the oil soaked lower drive belt from the engine pulley to the variable speed pulley on the transaxle. Now the tractor will not disengage fully from forward or reverse even after adjusting the idler/tensioner linkage from the foot pedal. There's some linkage underneath on the foot pedal that I didn't understand that's intertwined with the brake pedal linkage. My question is this: with the tractor in forward and my foot off the pedal the tractor shouldn't move because the mystery linkage shifts the transaxle into neutral or because there is enough belt slack that the drive pulley won't engage it?

 

[souNdguy]

Is this one of the models that has a cable operated tranny gear selector that has park at the bottom that you step on a brake to get to park, and has a little lever in a fender to select fore / aft?

 

[ScoutB]

There is a F-N-R shifter on the fender but it's a linkage rod to the transaxle, not a cable. The brake pedal is on the right and you lock it to park with a toggle on the dash.

 

[Hobo,NC]

I have got to re-do a gasket on one of those. I don't know what happen to the original gasket but the replacement slipped out of place. I assy it with out a gasket and checked crankshaft end play it was OK so did not use a gasket and used this.

https://www.permatex.com/product-category/gasketing/anaerobic-gasket-makers-flange-sealants/

 

[ScoutB]

I did a bit of research and found that it's pretty common for these motors to lose a crankcase gasket. I saw some photos online that showed just what I found - an inch or so of the gasket torn and sucked into the crankcase right by the starter. The advice I found was to use Permatex Hi Tack on both sides of the gasket. We'll see I guess. I hope your stuff works for you too.
My new gasket came with new bolts with pre-applied loctite and a tightening sequence with torque specs. The old bolts had no loctite and broke loose too easy. Maybe thermal cycling is what does them in.

 

[Hobo,NC]

Its been at least 3 years since I did the repair its held up they work the chit out of it I would say it gets run 4/5 hr a week maybe six 6/7 mon's out of the year...

I have built a few high HP 2 cycle boat engines and used only permatex aviation gasket maker to seal the crankcases.. Yes you fix may be a fix...Worst case you are only out a few hours to re-do-it...

 

[Hobo,NC]

The main reason the gasket moved it there lack of bolts used to clamp the SOB together...

 

[ScoutB]

(quoted from post at 21:34:32 06/09/16)
Its been at least 3 years since I did the repair its held up they work the chit out of it I would say it gets run 4/5 hr a week maybe six 6/7 mon's out of the year...

I have built a few high HP 2 cycle boat engines and used only permatex aviation gasket maker to seal the crankcases.. Yes you fix may be a fix...Worst case you are only out a few hours to re-do-it...

The original gasket went 12 years. If my repair lasts half that long it'll probably outlast the rest of the tractor.

Any thoughts on my drive problem? I'm going to adjust the belt as loose as it will go to see if that helps.

 

[Hobo,NC]

I have a limit on what I do I don't even like to put gas in my mowers.... I would not have tackled that job if it had not been for close kin....