HRR2168VYA rear wheel adjusters won't stay in place

[Claymoerni]

I've owned this mower for 7+ years and have never had an issue with it. 2 weeks ago while mowing, the right rear wheel adjuster came loose and the the mower dropped low enough to scalp the yard. I tried putting it back in place but there wasn't enough tension to allow it to stay locked in place. Upon further inspection, it seems the transmission shaft has developed some "play" and will now move side to side about an inch, giving either wheel adjuster the chance to become disengaged.
I contacted my local authorized Honda dealer and after consulting with the parts department AND the service manager, it was determined that there must have been some sort of failure inside the transmission to allow the "play". A new genuine Honda replacement transmission was ordered and I installed it this morning. Everything appeared fine and after mowing half of my front yard the problem reappeared. Everything pulled apart and reassembled as it should but the "play' is still there. The snap rings and spacers inside the mower deck are still intact, but it just seems like the spacing from side to side is a little too wide, allowing extra room for the transmission to "play" and cause the failure. Does anyone have any ideas on why this is happening and a possible fix?

 

[Claymoerni]

Well, after several hours of trying different fixes.I finally solved the problem with one flat washer. It had to be just the right size to slide on the driveshaft and had to be place first inside the right wheel dust cover before the pinion gear and two spacers. Everything is nice and tight and got the lawn finished with no problems.

 

[Briantii]

Consider cleaning the snap ring grooves and replacing the snap rings on the adjuster as well.