I am still in the process of working out kinks in my 350 5sp swap and right now the only problem left is that the transmission wont go into 5th gear or reverse. I was told that the transmission worked fine before and since gears 1-4 work great i believe it. Whats wierd is that the trans shifter will go into 5th gear position sloppily(without actually engaging) and wont go into reverse position at all. I really have no idea what else it could be other than the 5th reverse shift fork or something internal but if anybodys had any experience or even suggestions for testing anything with regards to my situation I would Greatly appreciate it.

 

I'm pretty sure 5th and reverse share a synchronizer and if its going bad then that could be your problem.. I had the same problem in my T-5 and replaced the synchros and everything worked perfect again.

 

reverse isnt synchronized

check the easy stuff first, see if theres anything lodged in your shift plate (under the shifter) or something :P
I say this because I just reassembled my t5 and threw it in the car only to find out I was stuck in 4th, then stuck in 3rd or 4th.. I didnt drive the roll pin for the shift lever flush and it was tearing into the bottom of my shifter

 

Sounds like while it was out of any car, some nimrod took off the bolt thing that looks like a drain plug except it's not, on the driver's side of the transmission (opposite side from where the plugs are); and the shifter link thing that falls off, is fallen off. So now the transmission has to be disassembled to put the little clip back on that holds the shift lever piece to the thing that looks like a drain plug.

OOoooopppss, that wasn't you that took it off, was it? Sorry, if it was.

 

That false drain pug thing just might be it. Looks like Im ripping out the trans tomorrow.

 

I had a Dodge 3500 diesel 4x4 in the shop yesterday. No 5th gear (OD). NF4500 tranny. Tranny oil was very metallic.

Pulled the tranny out to locate the problem and found it was in the back section. Took apart the back section where the OD gear is to find the retaining nut that holds the gear onto the shaft had broken and the gear slid back off the splines. Because of the amount of metal that contaminated the oil, we just installed a reman tranny.

The reverse and 5th use the same shift fork but not the same syncro. The reverse syncro is in the main part of the tranny and a secondary fork operates the syncro in the back section of the tranny for the OD gear.

Not sure what the T5's look like inside but the theory is all the same.