Slipping out of 2nd

[Oldfireguy]

After reinstalling the T90 with new blocking rings and small parts repair kit, trans still slips out of 2nd gear. This occurs when coasting to a stop after downshift, etc. It doesn't happen when upshifting. I also installed new poppet springs and balls plus a new 2nd/3rd fork in the tower. The small cogs in the syncro assembly looked OK as well. Along with the rear seal oil leak, I'm about ready to resign myself to living with the issue. I'm anxious to get the tub/front clip back on and start driving it. I definitely won't be tearing the whole thing down again. Thoughts? Thanks in advance!

[bmorgil]

The clutching teeth are probably worn on the second gear and shift collar. A common thing as a tranny wears out. especially if it had an EP oil in it for a while. The first sign is it spitting it out when you back off the gas, "coast". When it gets real bad it will jump out under load.

If you don't have the tub on yet, now is the time. It needs a new second gear and a second third shift collar.

[Oldfireguy]

I'm assuming that the shift collars are the same thing as "blocking rings". They're the yellow metal material. They are new on each side of the syncro. Clutching teeth looked fine on the gear itself, when compared to the new shift collar. Thanks for your input.

[bmorgil]

The shift collar is the piece that slides with the fork. It is the piece that first engages the Bronze Synchronizer ring or "blocker ring". Once it engages the ring it presses forward and engages the clutching teeth on the gear. The angles cut into those teeth and on the gear, are very precise. As they wear they loose surface area. This causes a lack of engagement force. It takes surprisingly little wear to start to loose engagement. You have covered the other bases that would make it jump out. A bad poppet spring, worn shift rail etc. The bronze rings wear on the inside at the cone clutching surface. They would not cause jump out, only difficult shifting. If it shift's well and the up shifts are positive and solid, it is most probably worn clutching teeth on the gear and or collar. There is not much else it can be in second gear, unless the gear is wobbling on the main shaft. You would have noticed that on reassembly for certain.

The attached photo shows too worn to stay in gear.

[Oldfireguy]

Thanks again for your time. Good stuff!