Fresh rebuild trans pops out of 2nd and grinds immediately

[InfernoAE86]

So, thanks to you fine folks, I finally have my car running. I had the T50 rebuilt with brand new OEM Synchros by a very reputable trans shop in the area. It shifts into all gears smoothly, and they operate normally, as confirmed by myself on the bench before install. Well, now that the engine is running, I have all gears BUT 2nd. When I try to shift into 2nd, it pops out and grinds immediately, as soon as I let off the clutch. This also happens if I try to hold the shifter in gear. The clutch seems soft, even though I bled it, and it seems like there isn't much pedal travel. Would my clutch pedal (hopefully) be a cause of this? I haven't had the chance to adjust it out further, but everything I've read says "Pops out of gear? Synchros are junk, time for a rebuild". I'm hoping this isn't the case, as I JUST got this old girl running again and don't want to pull the engine/trans again.

On a side note, anyone have a good all-inclusive W58 swap writeup?

[TORPARTS]

Take back to shop and tell dumb asses to open repair manual
And follow instructions


Based on this stupid monkey misaligned the synchros

Take it to a real shop

[InfernoAE86]

Like I said, they're a very reputable shop. Is it possible that 2nd has worn teeth or something? All i asked them to replace was the synchros, which I provided them with.

[jondee86]

5th Gear (Or Any Other Gear) Pop-Out

Unfortunately, there is a lot of misinformation out there about 5th gear pop-out
(or any gear for that matter) being caused by worn syncros or some other problem
with the syncros. The truth is, the synchronizer rings have absolutely nothing to
do with a transmission staying in a gear or popping out of a gear. Synchronizers
only function is to "spin up" the gears as the engagement hub approaches the gear.
For a detailed look check out HowStuffWorks: Manual Transmissions They have
an excellent section about manual transmissions and synchronizers.

On the problem of 5th gear pop out, there are two sources of problems that can
effect the "pop-out" issue. It doesn't matter if it is 5th gear or 2nd and it doesn't
matter if it is a Toyota transaxle or a Renault. Gear pop-out is related to movement
in the transmission. This movement can either be external or internal.

The above lifted from http://www.wcengineering.com/articles/popout.html

Most likely causes will be missing or faulty detent, bent shifter fork or some
other issue that prevents the gears from engaging fully. Talk to the shop and
see what they say.

Cheers... jondee86

[allencr]

No, it is not the clutch.
No, it is not the syncro ring.
Going into 2nd all the way, shifter travel as far for 2nd as 4th?
How far does it take to engage 2nd? Idling in neutral, push clutch down about 3/4 or more and start pushing shifter into 2nd, feeling when 2nd's teeth/dogs just start touching & bumping along against each other. Then pedal down all the way, to figure out how far the shifter travels between just starting to engage to going all the way in 2nd.

[InfernoAE86]

The above lifted from http://www.wcengineering.com/articles/popout.html

Most likely causes will be missing or faulty detent, bent shifter fork or some
other issue that prevents the gears from engaging fully. Talk to the shop and
see what they say.

Cheers... jondee86

Jondee, thank you for your informative, and objective responses. Obviously I'd have to split the case to check the fork, but the detents, I can check while the trans is installed, IIRC. If it were either of those issues, though, would it shift smoothly and operably, while the car is off? It worked fine on the bench, is why I asked.

No, it is not the clutch.
No, it is not the syncro ring.
Going into 2nd all the way, shifter travel as far for 2nd as 4th?
How far does it take to engage 2nd? Idling in neutral, push clutch down about 3/4 or more and start pushing shifter into 2nd, feeling when 2nd's teeth/dogs just start touching & bumping along against each other. Then pedal down all the way, to figure out how far the shifter travels between just starting to engage to going all the way in 2nd.

I'll have to check the 2nd gear shifter travel this weekend, as I'm on a work trip for the moment.Thank you for this test. I'll be sure to give you an update ASAP.

[jondee86]

If it were either of those issues, though, would it shift smoothly and operably,
while the car is off? It worked fine on the bench, is why I asked.

Not being a gearbox guy, I had to do a bit of research on this issue. Kind
of interesting, so worth the effort. From what I see, the gears are in mesh
all the time, either free-wheeling or locked to a shaft by the synchronizer.
Through some kind of special engineering magic, the dog teeth of the
synchroniser and gear are prevented from separating under load by the
geometry of the teeth. However, this locking mechanism requires the
dogs to be fully engaged.

Flying apart would therefore appear to indicate that the dogs are not
fully engaging. Testing by hand on the bench may not generate enough
torque to "pop" the dogs apart. The test suggested above would be a good
place to start.

Cheers... jondee86

[InfernoAE86]

Thank you again for being so informative and helpful. I'll most certainly be trying this out as soon as I get home on Friday.

[InfernoAE86]

Okay, I was home for the weekend, and I managed to play around with the car for a little bit. The shifter moves the same distance in all 3 axes for each pair of mated gears. I.e. As far rearward in 2nd as 4th and Reverse, and as far left in 2nd as 1st. Everything seemed normal, except for the same issue where it pops out of 2nd and grinds, even if i'm holding the shifter with quite a bit of pressure. As for letting out the clutch and seeing where it engages, it engages at the very beginning of it's travel, which is the same as on my x-runner. The first inch or two of clutch pedal depression completely disengages the clutch from the gearbox.

So, where do we go from here?

[jondee86]

What did the shop say ? They are the experts

Cheers... jondee86

[InfernoAE86]

You present a great point, unfortunately, one that I forgot. I'll give them a call tomorrow. I don't believe that they touched the shift forks, as I brought them the split case and main/counter shafts, and that's it. That being said, I remember the 1-2 shift forks face opposite directions per Chilton's manual.

[jondee86]

I have discovered over the years that even experts make mistakes. None
of us are perfect, and the difference between a reputable shop and a dodgy
one is that the reputable shop will recognise that it could have made a
mistake, and make every effort to fix the problem. Not that I am in a
position to say that a mistake has been made. Only that the defect you
describe tends to indicate an assembly error.

If the box did not jump out of gear with the old synchros, then it is highly
unusual for it to jump out gear with new synchros. See what the shop says.

Cheers... jondee86

[InfernoAE86]

Well, after being out of town for a while, and picking up another t50 from AZ, I finally got around to calling the shop. They said to bring it in, and they'll fix it. So it looks like I need to pull my engine/trans yet again. I'll probably drop in the new(er) trans for the time being.

[allencr]

Didn't care about the clutch pedal at all, only about the distance needed to move the shift lever from when the dogs just begin to touch until the lever is fully home into 2nd.
Probably like TORPARTS writes above, even when parts are almost symmetrical & can be assembled wrong, it doesn't take too much looking at the part to see that it it won't work too well assembled that way and that checking a manual can save a lot of grief.

[InfernoAE86]

Didn't care about the clutch pedal at all, only about the distance needed to move the shift lever from when the dogs just begin to touch until the lever is fully home into 2nd.
Probably like TORPARTS writes above, even when parts are almost symmetrical & can be assembled wrong, it doesn't take too much looking at the part to see that it it won't work too well assembled that way and that checking a manual can save a lot of grief.

Oh, now I understand. Well, after much cursing, the old trans is out, so I have no real good way of testing it. I'll update this when I get new information.