Craftsman lawn mower has bent crank shaft

[Rich R]

Hi All,

I'd appreciate any help or direction here... I managed to bend the crank shaft on my Craftsman lawn mover (model 917.378641) and this type of repair is not covered under warranty... so I was wondering if this is something I can repair myself. How difficult is replacing the crankshaft? I've done lots of suspension, exhaust and engine work on my car and have all the standard tools... any special tools needed? Is there anywhere I can find a service manual that can step me through this kind of repair?

Thanks and appreciate any help, RR

[David Martel]

RR,

Such repairs are not difficult if you have the skills needed to rebuild an automobile engine. It may be better to deal directly with the engine manufacturer or his local sales rep.for parts rather than Sears. I think you can get small engine manuals at many auto stores. Check the price on a new engine and decide if you want to tackle the job. If the lawn mower is old a new engine may be the better choice but you indicate that the mower is still under warranty.

Good luck, Dave M.

[RockingRC]

[Henry77]

Did you check with Sears - if they ask how it happened just feign ignorance - they will usually look the other way rather than lose a future customer (just from what I have heard ;-) )

[My Name]

RR... Take it a local auto parts store that has a machine shop. Quite often the crank can be straightened on a jig if they have one in the shop. Then get rid of this thing and buy a mower with a Briggs And Stratton engine on it so the key shears before the cranks bends. Most of the time the Sears mowere uses a Tecumseh engine with a hard steel key in the flywheel that does NOT shear when you hit something. B&S uses a soft aluminum key that will shear and thus cut out the engine by virtue of its timing to the magneto.

[e-mail] (Rich R) wrote in news: [e-mail]:

[PAROADHOG]

You might wanna check with a well equipped mower shop. There used to be a tool that was designed to straighten bent vertical-engine cranks in the engine. It was a crude procedure as i recall but often worked well and saved a lotta money on a rebuild.

[Nate Weber]

The only special tool you will need is a flywheel puller, I usually hold a block of wood on the top of the crank and hit it with a hammer to remove the flywheel.

Find all the numbers you can on the engine cowling and take them to a small engine place. They should be able to cross reference them to the engine model and supply you with the correct crank. Buy a mechanics handbook for you engine while you are there, about $10.00 iirc. Check the condition of the bearings before replacing anything, the bent shaft could have trashed the bearings.

Nate

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[Bruce]

Yeah, it's called a 10 ton press, a set of V blocks and a dial indicator. No sweat.

[Don Young]

[Jeff Cochran]

Pain in the ass to do yourself, but usually realatively inexpensive at a mower repair shop.

Jeff

[DR, Bob]

[Chip Stein]

all rotary mower engines used alluminum keys with techumseh and briggs. i've replaced and straightened hundreds of cranks in both engines. it depends on where the impact occured as to whether the crank bends. Chip

[Eric Tonks]

Don't tell Sears of your diagnosis, just tell them it doesn't work right, or that it shakes when running, or if it won't start, tell them that.

[Bruce]

You know, this sucks and is part of what is wrong with America. This guy runs his mower into a tree stump or a brick or something and now you're encouraging him to f*ck Sears because of his mistake. He needs to eat this one. The more people that play this game, the more we ALL pay for stuff from Sears. Grow up and take responsibility for God's sake.

[Eric Tonks]

One: his diagnosis may be wrong!

Two: Sears will check the engine out, or at least that is their job to do.

Three: Sears will then decide whether to send him an estimate of the repair, or they will decide to replace his mower under warranty. That is their choice and their decision.

Four: Not telling Sears of his suspected diagnosis is not cheating nor is it morally wrong. However, his diagnosis may taint the service staff's opinion with the idea that the shaft is bent, and they may not check to see if it is something else, which they should do. Often things are not what they seem to be.

[Bruce]

Well, to quote him, "I managed to bend the crank shaft on my Craftsman lawn mower." He seems to be pretty clear that there was an "incident" that bent the crank.

Sure but he should expect a charge for that if it isn't a warranty covered repair.

Fine but again, he should expect a bill.

I agree that it is ok to provide only symptoms if he takes it there but it would be morally wrong to NOT say, "I was mowing, heard a loud bang, motor quit. When I lifted the mower, I found a boulder hidden in the thick grass. It vibrated after I started it again."

[Jeff Wisnia]

I have a framed sign on my office wall. It reads:

"There is no right way to do the wrong thing."

Your advices speaks for you and says a lot about your lack of morality sir.

Just my .02,

Jeff

[Bruce]

Amen Jeff.

[Henry77]

Umm - whatever. The point of my post was to have Sears determine if they would cover it (as someone else suggested). If you are looking for Morality and are looking on the Internet for it your in for a rude surprise. Unfortunately it's a dog eat dog world out there in the real world.

[Rich R]

Wow... Thank you all for all your comments and recommendations. Just to make things clear... It's a Briggs engine and yes, it was I who hit a stump and bent the crankshaft. I new it was bent and Sears confirmed it with a $220 quote for repair. Instead of having Sears do the repair, I ordered a new shaft which cost me $75 including shipping and I'll attempt the repair myself.

Right now, I'm having a tough time getting the flywheel off. I'll try to get it off with hammering a piece of wood against it... although, I think I should find a repair manual somewhere for this Briggs engine... cause after the flywheel comes off, it looks like the lower pan needs to come off. It's looks challenging but should be time well spent tinkering in the garage.

Thanks again for all your help and direction.

RR