This is sort of a stupid question but I'm not clear on the differences between the f/r stationary gears on the 20B and 13B RE (2 rotor cosmo) and those found in the FD. I do understand that the FD uses better bearings in terms of oil distribution to the e-shaft. I've received a bunch of conflicting information which is leading to my confusion. I'll summarize....



Only one of the FD stationary gears is hardened (which one?)



It's adviseable to upgrade your 20B and RE stationary gears to FD (which one, or both?)



Essentially, should I be replacing both stationary gears in my Cosmo 13B (I've heard I only need to change the rear one out) and if so, are there other changes that are necessary? Do the REW thrust bearings and the REW's front counterweight need to be used in conjunction with the FD's stationary gears?



Thanks in advance. I'm not sure what ever happend to me just wanting to throw this motor in temporarily...curiosity got the better of me I guess :-)

the fd is supposed to use fd stationary gears, they share part numbers. however, the 20b ones might not be hardened? i dont know if the 13b cosmo uses the fd/20b style gears with the big thrust bearings and hardened gears. i would suspect that the 13b-re uses the "normal" 74-91 gears, and thrust bearings. they are all interchangeable though, and all the rotor wieghts are all the same



mike

One of the Cosmo gears looks identical to the TII gear. If I remember correctly, it's the rear. I have no idea about the front however....One of the popular mods to the 20B I believe is to use FD stationary gears. I don't know if that's all of them or just one, the rear, on the 20B. Anyone?

I couldnt say. Cosmos are completely a mystery to me.

Ok, apparently it's a good idea to replace both. I've found a used front, still looking for a rear stationary gear (FD). Anyone have one they would like to sell? Must be in good working order https://www.nopistons.com/forums/pub...#>/biggrin.png