MTD transmission grease
transmission model 618-0163a
The bolt that holds the differential gears together broke and busted up the aluminum case. I was able to come up with a grade 8 bolt that I cut down lengthwise to fit, that works well thanks to mownie for suggesting I use a grade 8 bolt. I also patched up the case with JB weld, aluminum scrap and fiberglass. I cleaned out much of the existing grease that was in there except for inside the differential.
I didn't take the steel cover off the differential partly because there isn't a parts diagram available and because so far I didn't need to.
I wanted to put the recommended grease back into it but MTD lists their Bentonite type 0 for $20 for 8oz and they don't have any in stock. The manual suggests using Shell grease which with a little research I found to be Shell Darina type 0 clay based. Apparently they don't make it anymore and nobody makes clay based at all anymore. The closest I found was Shell Gladus type 0.5 $6 for 14oz from Mcmaster Carr.
Here's my question: If I'm going to switch grease, should I open up the differential so I can clean out the old grease in there? I'm not sure I want them to mix but they likely will a little, maybe not? I was thinking I should pack more grease into the differential, maybe I shouldn't? Anybody have experience opening one of these up?
A related question is: how tight should I make the bolt that holds the spider gears together? If I make it too tight the axles don't move smoothly, I can feel each tooth engaging as the axles turn. I'm thinking of locktiting the nut on just barely hand tight. Any thoughts?