Sten's #00 grease. I use a very old hand drill with a 1/8" bit and carefully drill a hole as high as I can get on the box, near a corner. Turning the hand drill slowly brings out the cutting so it doesn't go into the box. Then I cut the tip off the grease bottle spout and inject as much as I can. You have to remove the tip from the hole a few times to let air off. Finally I put a small O-ring on a short self-tapping screw and plug the hole. You probably don't even need the O-ring but it serves to keep the screw from vibrating out. This will last for years. You may not have to do it but once, depending on how long you keep the mower.
I assume you hit the grease zerk fittings on the clutch assemblies on the rear wheel adjusters with your grease gun with #1 1/2 or #2 white lithium grease once a year, usually just one pump.

Thanks for the info Saxman1. I was thinking about removing the box case to repack it with grease but your method sounds easier.
Yes I always hit those zerk fittings at least once a year. Never had a problem yet with the clutch assemblies or the transmission gear box.

Hi 1saxman - I've got a 10515 (1995) with the tranny out as I was looking into some issues. All cleaned up and ready to be packed. The manual requests 6 oz of #2 lithium based grease. Is there anything wrong with using this, or do you still think Stens#00. Curious as your reasons.

And if I end up drilling a hole, don't you need a drainage hole as well - otherwise won't you be overfilling it?

If I end up keeping things simple and repack with 6 oz #2, how long until doing it again?

Thanks for any insight.

You do not want to over pressure the casing and damage a seal . lithium is old school lubricant , still has its uses but much better grade greases available today . I prefer Moly Grades , since they protect better from oxidations , galling and scoring of metal parts . In your application thinner lubricity is prudent since extreme pressures are not involved . Everyone has there preference , old grease over time and pressure or extended heat loses its lubricating properties as it drys out . Whenever possible , purging this old grease it better but not always practicable lol !

Thanks ssewalk1. An FYI there is no seal on this box (if that makes any difference to you). Are you talking about a moly grease like this you can find at Wallys?

So, are you also recommending to drill a hole as 1saxman does? And if so, a drainage hole at the bottom?

If the mower has ever been washed- it has water in it. It looks like you have pulled but not disassembled the transmission? Were you having binding when it shifted? If so, it should come all apart and be cleaned. If you flop the transmission on its top and remove the bottom cover you can semi clean it w/o taking the gears etc. apart. Get as much of the old grease that is stuck to the case as you can. There are no heat issues with these so it comes down choosing lube that is thin enough to be fluid enough to actually lubricate and thick enough to stay in the box. Like Sax, I think 00 is a good choice. 00 is kind of between grease and gear oil in thickness. Any other semi fluid lube could do the job. A number 2 lithium doesn't get mixed around enough to get where it needs to be and I always faulted Toro for that. You could take the opportunity to put a fill hole and plug if you wanted to top it off fresh every year or two. If you put enough lube in that would fill the bottom cover, that should work out. Seal the cover if you wish. The excess will just seep out the axle bushings.

Thanks tomplum. Over the weekend I removed the transmission and opened it up. I'ved disassembled the intermediate shaft and cleaned each of the parts. Removed and cleaned the pinion (that connects to the pulley). Kept all of the pieces on the output shaft but individually cleaned each piece on it as much as I could - about 99% clean.

Issue was a bushing on the output shaft (part 60-8850) is completely worn down. Never seen anything like it. Waiting on the this part before disassembling the output shaft getting the last 1%. I will replace this part and potentially the pinion/bevel gear/2 washers on the intermediate shaft (I ordered them and will look at their condition compared to the new ones before deciding.)

Your explanation regarding the 00 grease makes a lot of sense, and I like the idea of drilling a hole. What I don't understand is, if you only fill the box up to the top of the bottom cover, how does enough grease get to the intermediate shaft, and more importantly the pinion/bevel gear?

Also, if I follow sax's advice and fill it up to the top (which would surely be enough to cover the pinion/bevel gear, to your point, doesn't it just seep out the axel bushing?

The gears that reach into the lube will bring it up above as they rotate. If you feel that it should be higher to get the lube up above, that would be the right call. It isn't the end of the world if the box gets filled, but it will work its way out.

Another thing that just came to mind was that I put the mower on it's side to take off the blade / clean the deck a several times a summer. Even more seeping here? What are you thoughts on 0 grease - for example John Deere's 0 'Corn Head' grease. Yes it's less fluid, but it seems like there wouldn't seep, would it?

Tim , I think your over thinking the application . Since you have completed the most labour intensive work , simply repack with a quality grease . Being you have no seals , rather interference grade bushings then a general service grease will do. I only use Lithium on low pressure , heat applications on slow moving or revolving applications . Moly either M , MP or MEP on higher pressure , temperature and higher speed revolving applications . If plastics or rubber or synthetic fibres are involved then Silicone grease would be preferable . In your application I would advise #1 viscosity grease (soft) not semi fluid 00 or medium soft #2 . The fluidity of the grease will ensure adequate dispersal to required components . Unless your mower was submerged for a extended period of time very little moisture entrainment would be of concern . As I previously advised Quality Moly does have rust inhibitors which prevent oxidation should thermal heat cycles cause any internal moisture to accumulate .

The trans boxes I drill are the ones that are not readily serviceable. The ones with a removable pan without taking the trans out of the mower you obviously would take the pan off. If you plan on doing this at oil change time and you run it out of gas, you can turn the mower upside down so you can pack the box with grease. Yes, the lighter grease will leak around the axles but if you do this every year it will be adequate. Typically when you open one you'll find the #2 moly grease is solidified and can't lube anything. At least the lighter grease stays fluid and is carried by the gears.

When I say 'trans' I'm not talking about a multiple speed transmission - just the Toro/Lawn-Boy simple 'ring and pinion' that changes the axis of rotation. Filling it up is necessary because of the need to lube the top bushing on the vertical shaft.

#1 Moly will supply input and output shafts bushings and gear clusters with adequate lubrication without seeping out or hardening as OEM #2 does over time . This normally is required only once or twice during the life of a residential mower . Commercial units perhaps more frequently due to substantially more usage .