This mower wouldn't roll backwards, forward was fine. It's a 3 speed and it lacked power on a steep hill. When it wouldn't roll backwards, I took off the wheels and gears, and the shaft would then roll forwards and backwards and I could hear the transmission gears turning. I cleaned and lubed everything, and reassembled. After reassembly, everything worked correctly, except it didn't move quickly up a steep slope. After about 20 minutes of cutting, the rear wheels started having problems again rolling backwards. I finished in about an hour and the rear wheels wouldn't budge backwards. Any advise would be appreciated.

 

Sounds like trash is getting in the works and making it stick, or the moving parts are rusty? Did you grease the stuff, or just spray with lube? I'm having a hard time remembering what the drive system looks like on that mower, but I seem to recall a srping loaded pin that catches on the ratchet drive in the wheel in one direction, and ratchets freely in reverse. If this pin gets crud under it, or gets rusty or stuck, it won't allow the wheel to turn backwards. Does it sound like I'm describing comonents like your mower has?

 

Thanks Cheese,
I used lithium grease on the parts. The shaft spring that supports the shaft key on each side was clean. Each wheel ratchets when moving forward, but locks up when it tries to reverse. I think when it moves in reverse the wheels rotate the belt and allow the transmission shaft to turn with some resistance. After I had been cutting for about 20 minutes, the wheels started to drag in reverse. They would roll in reverse if I released the clutch lever, but after a while this had no effect.

 

Ok, I remember now...the spring loaded key. In fact, that wouldn't even cause it to not roll in reverse like I was originally thinking. I would suspect your cable is too tight for the self propel. There is an adjsutment (2 10mm nuts on the cable at the handlebar) to tighten and loosen it. See if loosening it helps any. If it is even slightly grabbing, it will be hard to pull backwards.

 

This must be an older Harmony II. It has a speed lever on the right side of the vertical support of the handle for speeds 1,2, and 3. This lever is held on by a 10mm bolt that goes thru a hole on the right side of the handle and a hole in the lever assembly. There is no apparent way to adjust this cable. I took the speed lever assembly off the bar and moved the cable around and it had no effect on the wheels being able to roll backwards.
It also has a bar on the cross/horizontal part of the handle that moves a cable to engage the transmission. This also has no adjustment. I looked under the housing and the cable is making its complete travel and moving a lever that goes into the transmission Again, I tried to move the wheels in reverse as I moved the clutch lever underneath the housing with no success.

 

Aw shoot...I'm striking out on this one huh? It'll help if I can dig up a manual on this thing. There are so many different harmony mowers, most of them very similar but just different enough to make it hard to not be specific. I'll see what I can find.

 

Thanks for hanging in there with me on this one.

 

Ok, the clutch cable on the left side of the handlebar (when viewed from the rear of the mower) is the cable that I was talking about. If it is even a little too tight, it will not let the mower roll back. It should have a spring on the end, then the cable housing attatches to the control box with 2 10mm nuts on a threaded end of the cable housing, correct? The other end attatches to the transmission. If it can't fully return to the relaxed position, this could cause it to not roll as well. (maybe grass is jammed in the way of it moving the full range of motion?)

 

Thanks cheese. The clutch cable and throttle cables go thru a housing attached to the vertical handle bar by one bolt. I did adjust the clutch cable by sliding it in the housing and retightening the bolt. This put more tension on the cable and was able to roll the mower backwards (yeah!) . Now the wheels have more reisistance moving backwards, and forwards with the tranny moving them, so I guess I need to play with the clutch cable some more?

 

Sounds like it. I believe that you'd want to relieve tension on the clutch cable instead of increase it...if I'm thinking right...but apparently increasing it has helped..so...

 

Thanks again for your help.

 

I also have the same problem. I cleaned all around the top of the transmission, and the arm on top where the drive clutch cable attaches moves very freely now. Still won't roll backwards, but will roll forward with ratcheting sound. I also cleaned all of the grass clippings in the rear wheel assembly, and make sure that the pin, and pinion gear was o.k., and put in correctly. Any thoughts on what might be my problem. Thanks.