T18 2nd Gear Shifting Issue

I've done a lot of searching and am struggling to find a similar situation.  The T18 was completely torn down and rebuilt(minus the upper shifter housing) with everything else.  Trans shifted fine in to all gears on the bench.  Now I can shift into every gear no issues except for 2nd.  The only time I can get into second is running to a stop and get lucky on timing.  I've been using 3rd ok to get going but don't want to try the clutch.  Any thoughts?  I've heard to check clutch adjustment but can't find any solid info on what to do.

Hydraulic clutch systems have no adjustment.
They are troublesome to bleed. Most of us suggest that if you can get the truck in gear just drive it and the bubbles will shake out up into the reservoir.

External slaves for the T-18 & 19 need a minimum of 5/8" 'throw' (actuation) and 3/4 would be better.

It could well be that your shift lever assembly is worn out or bent in some way, but you can catch 4th fine, correct?

I didn't think there was anyway to adjust it but wanted to make sure.  I need to confirm the throw still and will try to do that this weekend, but it doesn't hang up in any gear or grind, just won't go in to 2nd.

All gears are good except for 2nd.  I have considered the shifter but can't seem to find a Ford replacement, only straight versions.

I have also considered it might be a synchro issue, but no idea how to diagnose that.

The hydraulics were vacuum bled but it wouldn't hurt to confirm fluid level again.

Can you double clutch it into or out of 2nd?

If the case was torn down and rebuilt I'd expect new synchros if ANY wear was apparent.
If that was the problem the gearbox just wouldn't match speeds into and out of 2nd.

The fork could be bent or missing it's wear pads (but again, you pay close attention 🧐 to these things when the box goes back together)

Vacuum bleeding has failed for me before.
I bought an Excedy slave with an actual bleed nipple.
Then I took a clear tube and ran it up into the reservoir and just pumped clear fluid in an endless loop.

But I think if you have no problems with 3rd and 4th you don't have a problem with clutch release.
It really seems like a rail problem to me.
Let's see what others have to suggest...

I haven't tried to double clutch downshifting.  I never start in 1st so haven't tried it going up either.  The kit that used had subscription rings so they were replaced.  I'm also pretty certain the it contained the fork wear pads that I'm pretty certain were non existent on the factory trans.

This is the kit.
https://transpartswarehouse.com/bk114aws-ford-t18-2x2-4x4-4-speed-transmission-rebuild-kit-1965-on.html

My truck used to have a T-19 ( very similar w/ synchro 1st)
But it also had the plastic pads moulded into the forks, not little channels that slip on.

You might give double clutching a try just to see if anything is different.

I'm no expert but this is just a thought. You might wanna pop the lid anyway just to inspect. When you have it open, try putting the synchro sleeve into 2nd with your hands and see if it has more resistance than other positions. Things may be different than the bench now that the gearbox has spun under load. I'd want to find out if the top end of the transmission out of alignment or a shift detent is being stubborn. I figure if it was a seized blocking ring then you'd have grinding.

Double clutching hasn't seemed to make much difference.  Best luck I have is running to a stop and getting lucky.  I have zero grinding when shifting, although now that I'm paying more attention 3rd might be a little clunky.  It goes in with no issues, but isn't as smooth as 4th.  No issues with reverse either.  Wondering if I just need to buy the rebuild kit for the cover and get it done.  

My T18 was total junk and because I did not want to lay the truck up I bought a used NP435, still a granny first.

I dont sown shift into 2nd but to get it in easier I am rolling vary slow and double clutching and it will go in.
I do have to double clutch going up or down into 3rd as I think the syncro might be worn?

Now what I am not sure on is the main shaft end play?
I say that because I can hear a it clunk when trying to get it in to 2nd when slowing down to a stop.
I had to remove the front bearing retainer to cut it shorter when I installed the Advance Adapter over drive.
The front bearing retainer is what sets the shaft end play on how thick the gasket is.
I reused the gasket and used a little liquid gasket sealer when I put it back together and not add to the thickness of the gasket.

You also did not say what type of gear oil you are using.
I will not use any gear oil that is marked GL-5.
If the bottle says compatible with GL-4 or later I will not use it and this is all you can find in stores.
I use Red Line MT-90 and it did make the trans shift easier.
It was also sent with my over drive unit and why I went with it in the transmission.
The other oil I think is good to use is Royal Purple but would need to re-check that to make sure.

In my case other than the hard shifting up & down in to 3rd, double clutching helps, and that is not all the time, I am ok with my NP435.
Dave ----

Check with NAPA; they sell a straight 90w GL1 mineral oil that I've seen recommended for the "earlier" transmissions.  I bought a gallon and filled my T18 up with it.  I've only got 120 or so miles since the trans swap, but it shifts pretty well.  Of course the unsynchronized 1st can grunt every so often when you shift into 1st, but I typically have been taking off in 2nd anyway.

https://www.napaonline.com/en/p/NHF65201

This is what I ended up going with.  https://a.co/d/g7ukfiV

Glad I did though since the PTO cover is leaking.  Not terrible, but enough that I'll have to drain it and redo it.  I will try to pickup some Redline before I fix it, but funds were tight when I was in the midst of buying all the parts so went with what I could get locally for a decent price.