Craftsman Lawn Tractor Problem

[Dimitrios Paskoudniakis]

My Craftsman Lawn Tractor (917.275702, 24 HP, 48" deck, electric start, automatic trans), is now 6 years old.

Today in the middle of mowing my 1 acre, I noticed the transmission getting sluggish, more and more so. I'm 90% done cutting the grass, but it barely moves and I cannot finish mowing with the tractor.

I occasionally tried to disengage the transmission then bleed air by moving the gear shift forward and back several times, but no improvement.

The manual indicates it could be just about anything: too much grass under mower, dirty air filter, dirty oil, faulty spark plug, dirty fuel filter, stale/dirty fuel, water in fuel, loose spark plug wire, dirty/clogged muffler, loose wiring, carb out of adjustment, or engine valves out of adjustment, or motion drive belt.

The engine sounds fine.

Based on experience, can someone point toward a specific issue? Can the transmission itself be shot? The manual didn't show this, but did suggest all of the above possibilities.

[WW]

My first thought would be check the belt drive. WW

[willshak]

WW wrote the following:

That was my first thought too. Belt slippage.

[clare]

And then the hydrostatic fluid level. But yes, the transmission itself could have failed. Important to keep the oil coolers clean - and common for them to be plugged with gras clippings.

[dadiOH]

Check the belt idler pulley. Whole belt too.

[Hustlin' Hank]

Your problem is a little vague. Here is a list of things we need to know........

Does the engine start and run as it should with the mower dis-engaged and sitting in neutral gear? If so, then it is probably not an engine problem.

Does the engine sound/act sluggish when you engage the blades or start moving? If so, could be an engine problem.

Does the mower move as it should with the deck dis-engaged? If so, possible deck problem. (grass build-up, bad spindle and etc.)

If the engine runs good and it seems to have enough power to run the deck, then check hydrostatic fluid level, belt adjustments to rear end.

I have also seen flat tires that are slipping on the rim cause the mower from moving. You can't see them from the drivers seat. Check both sides as your mower probably don't have posi-traction. Another possiblity is the key-way between the axle and rim is missing or broken. I have also seen this once on a mower where the guy took the tire off and forget to put the keyway back in.

Hank

[Dimitrios Paskoudniakis]

I removed the mower deck and saw that there is quite a bit of slack in the drive belt. It also has thin vertical cuts along the inside of its entire length. At one point the belt is supposed to be suspended above a metal bar that surrounds it (center span keeper), but the belt was dangling below. I also noticed a plastic housing that is part of the engine pulley and has clips to connect to a metal housing below (transmission?) is loose. I can easily lift it. Not sure what is normal and not here, but it seems I should replace the drive belt.

[hrhofmann]

This is a SEARS unit, isn't there an owners manual showing exactly how the various parts go together, and a list of maintenance items?

[Dimitrios Paskoudniakis]

Yes. In fact I see I have a replacement drive belt.

[Dimitrios Paskoudniakis]

The drive belt was replace and no noticeable improvement. Hydrostatic fluid will be next.

[Jules Richardson]

Assuming that the engine itself is producing the expected amount of power, some other thoughts:

bad pulley bearings, bad engine mounts, weak tension spring (or fouling of tension mechanism), oil leak onto crank pulley

cheers

Jules

[Andy]

Dimitri,

If , when you have the machine running normally:

If the belt is moving normally, And the drive pulley to the transmission is turning normally, And the shaft from the pulley into the transmission is turning normally, then the trouble is in the transmission....

One caveat, -- one poster suggested that both back wheels may be flat and spinning on the rims... I've never seen this, but it's easy enough to check...

Other than that, it's the transmission...

Andy in Eureka, Texas

PS I, too, have a Craftsman lawn tractor, but no hydrostatic transmission.... I have had no problems with mine....

[Hustlin' Hank]

I agree with your assessment except there is a possibility that the key-way that keeps the rear wheels from turning on the shaft could be sheared or missing also. I have never seen a sheared key-way on this model, but I have seen them missing. Probably due to the owner forgetting to put it in after changing a flat tire.

We'll probably never know the reason.

Hank

[Andy]

Andy comments: Thanks, Hank... I completely overlooked that ..... Andy in Eureka, Texas

[Dimitrios Paskoudniakis]

All, it was the hydrostatic module. Replaced, and it runs great. The module, from Peerless/Tecumseh, is a piece of garbage. Unfortunately I had to replace with the same model.