BJ42 1st/2nd gear synchro? Not shifting into 2nd gear (1 Viewer)

[TristanFF]

Okay so basically from what I can tell in the H42 and H55(?) transmissions, only 3rd and 4th gear have the typical brass synchro gears. 1st and 2nd shift using a specialized 1000 dollar “ring” as toyota calls it or “piece” as everyone else seems to call it. It’s a shifter dog, reverse gear, 1st synchro and 2nd synchro all wrapped into one ridiculously expensive unit. I am having an issue with 2nd not wanting to cooperate. It doesn’t want to go into gear when I’m going up or down, it can be used if I shift in a 1-N-1-2 fashion. Sort of a double clutch idea, but if I unload the transmission and start decelerating in second it throws the stick back into N. So, can someone explain to me how this “piece” works without having brass synchro gears? And if anyone has any clue as to what’s going on with this transmission issue please chime in also.

Fixes that have not worked so far:
Replaced the shifter seat
Replaced the shifter pins
Replaced the master cylinder
Replaced the slave cylinder
Replaced shifter locking retainer cup

Transmission was rebuilt using a terrain tamer bearing and seal kit less than 20k ago, new pilot bearing, transfer case was redone at the same time, after replacing the shifter pins and seat it worked perfectly for 3 days then stopped again. (Just to add some confusion I suppose). HELP

 

[charliemeyer007]

So who did all this work? Back in my aviation days the shop I worked at rebuilt helicopter transmission. They were expensive because we put in a lot of new parts, not just the one that were out of spec. The fly boys next door bought some cheaper "rebuilds" but those never made it to the end of cycle because the worn parts that were technically correct didn't last, they didn't buy those anymore because in the long run they actually cost more.

Just because they are "new" parts doesn't 100% mean they are good, or correctly installed. A worn gear installed on a new shaft likely works about as well and as long as a new gear installed on a worn shaft with a loose keyway and a sloppy it in the case.

Goes bad in 3 days - that could be about 3600 miles at the most - should last longer than that or the 20,000 or that matter.

good luck

 

[TristanFF]

So who did all this work? Back in my aviation days the shop I worked at rebuilt helicopter transmission. They were expensive because we put in a lot of new parts, not just the one that were out of spec. The fly boys next door bought some cheaper "rebuilds" but those never made it to the end of cycle because the worn parts that were technically correct didn't last, they didn't buy those anymore because in the long run they actually cost more.

Just because they are "new" parts doesn't 100% mean they are good, or correctly installed. A worn gear installed on a new shaft likely works about as well and as long as a new gear installed on a worn shaft with a loose keyway and a sloppy it in the case.

Goes bad in 3 days - that could be about 3600 miles at the most - should last longer than that or the 20,000 or that matter.

good luck

I did the rebuilding in question. Using what I thought were good quality parts, all the bearings and seals were replaced and I inspected all the gears/shafts when it went back together. Worked great for a few years then suddenly lost second. That’s when I changed the shifter seat and shifter pins, worked great again for a few days then turned back into a 3 speed.

 

[peesalot]

FWIW the only time I lost 2nd and remainder worked was when the rear output bearing took a dump, lets output shaft and everything on it slide back a bit causing that 1,000 piece to not slide right. I dont think it can go back far enough fo rthe needle bearings between the input & output to drop out, thats why it stays working. The tapered ends on that piece cause it to spin, kinda like a torque converter, did you put all the snap rings & spacer in correctly when installing tcase ? sounds like the rear bearing is toast or not installed right.

 

[TristanFF]

FWIW the only time I lost 2nd and remainder worked was when the rear output bearing took a dump, lets output shaft and everything on it slide back a bit causing that 1,000 piece to not slide right. I dont think it can go back far enough fo rthe needle bearings between the input & output to drop out, thats why it stays working. The tapered ends on that piece cause it to spin, kinda like a torque converter, did you put all the snap rings & spacer in correctly when installing tcase ? sounds like the rear bearing is toast or not installed right.

Yeah I’ll open it up and take a look at that rear bearing. Would be really annoyed if that’s the case because it’s a KOYO bearing and has barely any KMs on it so will report back on that one.