My Lawnmower Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
I use a Craftsman 6.75hp self-propelled walk-behind mower to maintain a very rough one-acre property. Been using this mower for 15 years now, and frankly I'm amazed at how well it's done.

PROBLEM
Viewed from the operator's position (behind the machine), the left front drive wheel is very strong, always turning/driving, no matter what. The right drive wheel has recently stopped turning whenever unusual pressure is applied. In other words, when the machine and I are moving forward normally, both wheels turn and appear to be propelling the machine; if I raise the front wheels off the ground, they both turn. BUT if I lower both wheels to the ground with the drive engaged, the right wheel will stop turning, while the aggressive left wheel continues to claw the ground. Typically, both wheels would turn aggressively.

BEFORE I start pulling things apart
, can anybody clue me in as to what to look for?

About three years ago I replaced the gears in the front-wheel-drive self-propulsion drive housing. That's because BOTH drive wheels had become progressively weaker until they finally stopped pulling the machine forward at all. The current issue involves only ONE drive wheel, so I'm wondering if maybe a few plastic gear teeth inside the right wheel have sheered off. I hope not - those wheels are ridiculously expensive and must be purchased in pairs.

Thanks


 

·
Registered
Joined
·
5 Posts
Discussion Starter · #2 ·
Asked and ANSWERED...

Well, I took the left wheel off, and sure enough...half the teeth are sheared off. See image below.

Literally one half of the teeth are gone from just one side of the wheel...

Does something like that happen all at once, as the result of one single event? Or does that kind of wear occur gradually?

The fact that only one half of the circumference is affected, and the other half is not affected at all has me stumped...



Notice there's a chunk missing from the black plastic perimeter, at the top of the image. Maybe that and the weird wear pattern indicate a one-time "event"(?) This mower suffers a lot of "events" but I don't recall any one that was particularly "eventful"...

Any insights are appreciated.
 

·
Premium Member
Joined
·
5,898 Posts
Was there an impact event that knocked the wheel out of round or a premature wear in the impact area that progressively got worse? Make sure the axle doesn't have a pattern of wear on it. How does the drive gear look?
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #5 · (Edited)
Thanks, guys. I don't think there's anything unbalanced about the propulsion transmission. And those steel gears at the ends of the axles look perfect. BTW, steel gears vs. plastic wheel teeth seems like an "unfair advantage" to the gears (or maybe just a ripoff - an "unfortunate design flaw" ensuring future sales of LOTS of replacement wheels...

Typically I leave about half the property overgrown and the surface there is pretty choppy (rabbit burrows, etc.). I raised the deck as high as it would go and tackled that area on Wednesday (yeah, I wish I had a bush hog, lol). That's when I noticed the problem. And yeah, I did run into several trees along the way...and lots of unexpected holes, so maybe one of those impacts caused the damage to the wheel teeth.

It's odd though. The first set of wheels lasted about 12 years, and my recollection is that all the tire tread was worn off them, but the teeth remained intact...

I dunno. Anyway, yesterday I found a used tire/wheel - tread half gone, but fully-intact teeth. It cost me $5 (vs. $22 from Snears). I installed it and I guess we're good to go.

I'm going to keep that overgrown portion mowed from now until I sell the property, so hopefully no more "events".

Tom

Correction: My post above said I pulled the left drive wheel, but in fact, the right wheel is the problem.
Correction: Replacement wheels can be purchased form Sears individually, for $22(!)
 
1 - 7 of 7 Posts
Top