Saturn Overdrive syncro.

Well Thought I 'd share this .. Was always curious if the T-90 brass synchro. would interchange with AD Saturn overdrive .. I had a grinding issue going into direct gear. So I installed a new T-90 synchro. ring. I compared the two and the only difference was ,that the T-90 was about .035 " thicker than the Saturn ring. So I put it in anyways, and went for a test drive. No more grinding going into direct.
Does anyone have anything add to this ?... I don 't think the .035 difference is going to matter...

 

I used to experience some gear clashing with my Saturn. This kinda hard to explain, but I'll try anyway. When shifting the OD I always shift "up" first, either the tranny or the OD. By that I mean if I'm in 4th and I want to downshift to 3rd gear OD, I shift the OD into Hi first, then shift the tranny down to 3rd, no clash. I go opposite direction if I want to shift from 3rd OD to 4th. That is, I shift the tranny "up" to 4th, then shift the OD into direct, no clash. I don't know if the clashing is related to the size of the gears and reciprocating parts in the T18 or not. They are heavy and I imagine hard for the little synchro in the OD to slow down. This works for me and I have no gear clashing.

 

I've found that the OD shifts better if the main transmission is in neutal. I think the synchro in the OD as John says is so small it has trouble changing the speed of the entire main transmission gears, shafts and even the clutch disk.
If the main transmission is in neutral, all the OD synchro has to overcome is the inertial of the transmission output shaft.

I also have good shifts from 2nd OD to 3rd direct (T14 3 speed) by moving both shifters at the same time. This is doing the same thing, the OD synchro only has to change the speed of the T14 output shaft.

Don

 

Are the T90 sychros the same size?

 

Yes that makes sense as I do have the Scout T-19 in it . (my modified M-38 ) . Over time ,the grinding had gotten worse .This seems to have fixed this.. Yes the sychros are identical except the T-90 ring is about 035" thicker... every other measurement is the same...

 

Nevermind. Answered my own question.