Toro 20334 Personal Pace Mower - Strange Noise When Engaging/Disengaging Drive

[cruise42]

Rivets...I did try moving transmission shaft in all directions both sides...all was good. When I change out pinions I'm thinking of stacking a few extra thrust washers on each side of mower between pinion and adjustment bracket to take out some of the axial float of transmission shift in attempt to keep pinion & wheel gear teeth better engaged. It would be nice if Toro increased face width of wheel gear...that way forces would be reduced/more evenly spread across width of mesh.

What do you think ?

Bill

 

[Rivets]

Sorry, my mistake. I reread the entire thread before I posted and I combined different problems into one answer. That’s what happens when there are posts about different models in one thread. For cruise42 you have worn drive gears, which will cause the grinding sound. I have seen the pinion and bevel gears inside the tranny wear, but very seldom, unless severely worn do they make noise. Most of the time this wear is caused by the bushing on each side of the tranny wearing first, then taking out the tranny gears.

 

[cruise42]

Hey Rivets...

Any idea what year Toro stopped using some form of spring loaded key clutch mechanism on their rear wheel Personal Pace lawnmowers ?
My Model 20334 (2016 vintage) has no such key. Drive pinions have squared off bores that lok it to transmission shaft having milled flats on each end...no keys.

simplifies drive system but when you stop to think about it you are constantly pulling thru slipping belt when dragging mower backwards. System relies on drive belt going slack due to transmission rotating forward towards engine decreasing tension on belt.

Would much rather have drive pinions keyed to shaft with some form of clutch mechanism that would engage drive pinion when going forward and allow pinion to basically freewheel when backing up.

Interested in your comments.

 

[slomo]

I've opened a couple of those transmissions up. All were bone dry lacking lube. Gears were noisy as you might guess. Cleaned them out with Diesel and an old paint brush. Refilled with 00 Snapper grease if I recall correctly. Took all the noise out. The ones I did were on Super Recyclers.

slomo

 

[Rivets]

Toro switched to keyless drives 6 or 7 years ago. Your understanding of the keyed drive is not quite right. The only time the key disengages is when you pull back on the unit, allowing it to roll easily backwards. The belt drive system is the same on both units. I have not run into any units that did not have grease in the trannies.

 

[cruise42]

Rivets...I took a real hard look at LH side of mower. It does appear wheel axle bracket is slightly "toed - in". If I force wheel straight grinding noise is greatly reduced. Have you had any luck in hard swimming bracket to correct toe-in ? Would you consider use of steel washer shim permanent fix ?

I'm guessing bracket and/of steel deck deflects when pivoting mower on rear wheels to navigate turns,etc.

 

[Rivets]

Pretty hard to bend that large bracket and deck, but anything is possible. Because the tranny is closer to the left wheel (where the belt tension is) I’m still leaning toward a worn bearing, bearing hoc and bushing on that side. Any or all of these is possible, but I’m not there to see what you see. How you proceed is up to you, but trying to find a shim and installing it is not something I would try without removing and inspecting the parts I talked about.

 

[cruise42]

Rivets...

Finally got around to replacing Drive Pinions on both sides of mower. Noise is greatly reduced especially these are straight cut gears running unlubed.

Still more noise than I'd like on LH side of drive. Even though bearing, sleeve bushing look tight I'm going to replace. Can you tell me how pivot arm is held in place ? Does it screw onto bearing retainer, or is there a retaining ring I'm not seeing ?

Thanks for your help.

 

[Rivets]

What do you mean by pivot arm?

 

[cruise42]

What do you mean by pivot arm?

"Pivot Arm" is flagged as Ref. # 8 on pages 12 and 13 of attached Toro Parts Manual for my specific Model and Serial No.