TravisBiggie

Yes, I spent an hour reading threads on google.

Recently rebuilt a y1 transmission. replaced 3-4th synchros, along with a synchro hub.

Customer says 1-4th work fine, 5th gear pops out and never engages, and even when he holds the shifter in place, it grinds.

The guy who installed the tranny is mechanically inclined, nothing new here. Fluid was not low, fill to spill. New hasport shift linkage, new mounts, no leaks.


So, the guru I go to, is saying its either the gear itself, or the synchro hub, but when I'm reading online, I am hearing it can be the synchro, the synchro spring, or the main shaft bearing (i didn't read anywhere online it could be the hub, or gear)

I need some help. Thanks

Caoboy

Yep. Most likely if it's not going into gear at all, something is locking out, either synchro spring not installed properly, hub synchro not installed properly, hub is blown up (shouldn't be since you just opened it up, you'd have seen that) or the gear dog teeth are messed up.

Sounds like it needs to come out and be inspected.

TravisBiggie

thanks for the reply. its already out and i'm dissecting it tomorrow. just wanted to get some insight. The weird thing is, everytime we rebuild a tranny, we shift it and make sure its going into every gear, so I'm scratching my head as to why its not going in gear at all.

Caoboy

It'll definitely help if you take some pics and post them, before you take the transmission apart, or while you are, other more experience people will chime in.

TravisBiggie

I'll snap some pics.

I'm having a feeling the synchro hub is bad, it didn't look the absolute best, we can had to grind some lips off it, but it shifted just fine, what has me curious is as to why it won't go into gear. Is it not going into gear perhaps of the synchro assembly, because the transmission is moving? Much different than changing the gear with it out of the car vs it rolling I'm assuming... since the synchro assembly is specifically made to change gears while rotating? I'm still learning some what.

I am actually ripping it apart today around 5pm, if so, will post pics up later. I appreciate the responses.

holmesnmanny

The main question is was 5th originally working to begin with ? If so, then something must not be reinstalled properly or maybe something was floating around inside. It's likely you will need to replace the hub, synchro, spring, and gear to be sure it's fixed. But you will be able to see the damage when you take it apart.

Let's see some pics.

24TEN

iTrader: (2)

Very faint possibility but the little clevis piece that the interlock guide bolt rides along may have been slightly bent during reassembly. It's happened to me.