Difficulty backing up..self-propelled LawnBoy F-engine 680546

Phototone

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
I have this very nice self-propelled LawnBoy aluminum deck F-engine, Walbro metal carb mower, Model 680546. I have cleaned the wheel gears, both drive "dogs" engage and there is no resistance rolling forward. The self-propelled works fine. The ONLY thing is that there is a lot of resistance pulling back on the mower. The self-propelled disengages just fine when you drop the bar on the handlebar, but
there is resistance in pulling back, like you mow into a corner and you have to pull back manually to get out of the corner. Any advice?
 

lewb

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
I am assuming you have the same drive system I have on both of my LB's self propels, Sounds to me like the key is not rolling back into the groove. I did have a friction ring (rubber o-ring seal) that worn, the issue I got was not driving that wheel. Could be the plastic washer clutch that the key slides into when it disengages. If they ran out of grease I suppose they could wear out, both of mine 93 and 2000 work fine. Partstree should have all of those parts instock if you want to rebuild each drive assembly. Spring could be sacked out as well, mine seem to be ok.

I would clean everything up and inspect (probably will not see any wear) re assemble with new grease and see if you can get key to slide in and out with sprocket. I really like this design as it works well and seems to be very durable.
 

lewb

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
Looks like you have a different wheel drive but seems to be very similar. Spring tension may be something to look at as I believe that pushes the key when the wheel stops driving.
 

Phototone

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
Looks like you have a different wheel drive but seems to be very similar. Spring tension may be something to look at as I believe that pushes the key when the wheel stops driving.

My drive is NOT the drive as found on the "V" and "Duraforce" models, rather it is a slightly older drive system.
 

bogdaN

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
I see few having same problem,and it is in the gear box.
 

Phototone

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
Re: Difficulty backing up.I fixed it.

LB1.jpgLB2.jpg

Above are 2 photos showing what type of self-propelled transmission I have on my late model "F" engine mower. I rejected the idea that it couldn't be solved, so I took everything apart, and dismantled the tiny multi-plate clutch and washed each blade in carb cleaner, got everything inside clean and oiled and regreased and now it works like it should. The release and pull back on the handle are effortless. When you pull back on the mower, if the clutch friction discs stick or bind it makes it very hard to pull back. They need to be clean and not stuck to each other. This type of transmission does not loosen the belt when you release the drive bar on the handlebar, rather it releases pressure on the internal clutch.
 

bogdaN

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
You did job that not to many would do.I did many years a go and work.
 

bwright1818

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
Congratulations and nice work! I have had a number of machines with that drive and that problem. I am usually a glutton for punishment but I never went in that deep. I always looked at it, gave it some thought and sold the machine!! It did usually get better after using it for awhile...The machines with that drive are usually on the heavy side, anyway. I find it easier to use a light machine with NO self-propel, than to use one of those fancy guys, even when that clutch had limbered up with use.....Still, my hat of off to you! And is good to know that if I get another one, that there IS a solution. Thanks for posting it!
 

Phototone

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  • / Difficulty backing up..self-propelled LawnBoy F-engine 680546
Congratulations and nice work! I have had a number of machines with that drive and that problem. I am usually a glutton for punishment but I never went in that deep. I always looked at it, gave it some thought and sold the machine!! It did usually get better after using it for awhile...The machines with that drive are usually on the heavy side, anyway. I find it easier to use a light machine with NO self-propel, than to use one of those fancy guys, even when that clutch had limbered up with use.....Still, my hat of off to you! And is good to know that if I get another one, that there IS a solution. Thanks for posting it!

The transmission is not very complicated inside, actually has less parts than the self-propelled used on a DuraForce. The reason I went to the trouble was because this IS a lightweight mower, with the aluminum deck and all. Lighter weight than my Silver Series and Duraforce steel deck self-propelled.
 
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