I don't know what is recommended either. I tend to lean towards overkill maintenance for my Lawn Boy 10552 (same as yours + electric start).

With that in mind, I used Amsoil 2000 Synthetic Racing Grease in mine. Since these 2 cycles are no longer made, maybe my Lawn Boy will be "the last man standing". (If not, maybe the gearbox will). No problems here (I use it every week). Synthetic Grease is cheaper than discontinued Lawn Boy parts.

I would agree that the best thing is to pull the cover and lube. Anything will do for lube. #2 lithium I believe is what it was born with. Also, if you wash your mower- keep the stream away from the box as they are sealed poorly.

OK...Thanks for the info. I like that "last man standing". All of us die hard LB fans want to be in there too.

You may want to consider drilling the pot metal housing for a grease fitting, just make sure to pick a spot where the zerk doesn't interfere with anything internal or external. You can give the gears a shot of grease the same time the wheel drives get it.

weed cutter is right. It has been discussed before that the best way to maintain the gearbox is with the addition of a zerk fitting and regularly greasing it. Another good point is the one about washing. These gearboxes are not meant to be washed.

If you pull the cover to lube then take the time to remove the old grease which is likely thickened and caked on the inner sides of the case. Then add one of the new lubricants.

A side note -
To much grease into the wheel zerks may bind up the prawls on the axle that allow free-wheeling in reverse, making it difficult when you pull back the mower. I give mine 1 pump from the grease gun anually and they may still hang up for a couple of mows.