I bought this 84 Z28 H.O. Two years ago and enjoyed every one of its period correct 200 horses. So much so I blew up the stock NWC T5 in a year. In hindsight that was an awful idea.

I let the car sit for about 3 months while life got in the way of picking up a junkyard WC T5 and doing the swap. I finally pulled one out of an 89 and when I got home I noticed there was a bit more play than I would have liked in the input shaft. So I went out and bought the do it yourself DVD, some shims, synchros, and some other little things like snaprings . When I got into it I noticed it was bad, really bad, and the output shaft had worn the input-output shaft mating surface into a cone where the roller bearings should go. The output and the input where toasted. At that point I just should have said "I'm an engine guy and I'm too broke to do this the right way" and gone out and bought an s-10 one to get me by.
But I didn't, I went further into the project, then more personal drama happened, and I had to stop with two boxes of trans parts in my garage.

Then after about two months I finally had time to get into it and swap the output shafts, I didn't think it could be that bad. It was and I had parts everywhere and the thing ended up with a WC case, countershaft, and overdrive with an NWC input, output, and shift linkage/cover. So the thing was a bastard and required a shim between the 5th cog on the output and the snap ring but it shifted great on the floor and I thought I had done a good job.

I go ahead and throw it in my car with my buddy today, thing fires right up after sitting for far too long, I get all excited to pull it out of my driveway... and no 1st! I was able to pull out in 2nd though and took it for a little drive to the gas station a mile away to see what else was wrong. I do not have 1st or 3rd, it gets stuck in 4th, pops out of 5th, and reverse and second work beautifully. When trying to pull 1st or 3rd it just acts like the gear isn't there, I actually tried holding it in 1st and ended up with a bit of grinding and decided to back off. Rest of the car is running great too and I really want to drive it while I still have some summer left but I cant.

So now I'm wondering what could be wrong, almost sounds like its a linkage issue to me, not anything internal. I really don't know what I'm doing and I thought I'd come here for some guidance on where to start.

 

Thought I'd put this in a comment as bit of TLDR summary.

Built my tranny to the specs in the DIY DVD. Its a bit of a bastard child of a WC and NWC but as an engine guy and an amateur machinist feel like the things I did that were custom internally were not bad. That said now that its in the car I can't get half the gears (only have 2, 4, and R and 4 is notchy and gets stuck). After thinking about it, and after posting my first comment, I'm starting to think it may be that the shifter is being limited some how when trying to go into those forward gears. So I'm going to pull the rear top cover thing and investigate tomorrow and I hope it turns out that I just made a careless mistake and left something in there and it is limiting the travel.

The shifter is an aftermarket Hurst one but it worked well before I did the rebuild so I can't see it having clearance problems now...

 

Went out to the car today and swapped out the Hurst shifter for a stock one that doesn't have anything to limit the travel, same problem. I was actually able to hold it in first when I first took off but couldn't get it again and now its making a lot of noise in 2nd. I didn't get past that but it doesn't really matter at this point I'm thinking. Sounds like something is very wrong in the case.

So unless the internal linkage is somehow capable of making noise I'm going to be pulling this one again...

Anyone in Indiana looking to sell a t5?

 

Sounds like you may need to remove the top cover and post some pics.

 

my rebuild has been a nightmare to, not as bad as yours (I hope, still working on it) but that's why I always spin it and shift it before putting it into the car. but sounds more like sncyros or possible gears in the wrong place? bc the linkage is 1-2 shift fork, 3-4 shift fork, and 5th/rev shift fork. im surprised sofa or jmd hasn't chipped in, they were great helping me.