I have a 1986 with 50k miles on it. I took it out for a drive and it made it to my driveway with no problems. Coming to a complete stop, I attempted to let out the clutch to pull up slowly over my driveways dip and it died. Attempting to restart it, it kept dying when letting out the clutch. It wouldn’t even jump forward like a car does when you kill it. I tried to put it in neutral in order to push it in my driveway and it still wouldn’t move. The car wouldn’t budge. I disconnected the driveshaft and pushed it into the garage as it was quite a hot week. Reading forums, it seems like the 4+3’s are common to have linkage problems. I have disconnected the 3 linkages and attempted to put it in neutral with the 2 main levers in the up position. After, I tried spinning the driveshaft with my hands, thinking it is now in neutral, and it still won’t spin. I am going to take the cover plate off next but wanted to get any ideas that you guys may have. I’m thinking I’m more than likely going to have to pull the transmission out. Thanks in advance!

 

Is there any oil in it? It's not a typical way for 4+3 to fail. Does the clutch fork move when you have someone step on the pedal?

 

Hey man! Thanks for the reply. So there was plenty of gear oil. There was a tad bit of metal dust that I collected with a magnet. I mean just a very small portion. However, sitting on the bottom of the gear case was a full sized washer. It wasn’t torn, beaten or broken. A full size washer about 3/4 inch in diameter. It blows my mind how it got there unbroken or not chewed up lol I pulled the transmission today and is in neutral. The gears spin perfectly while turning the input shaft. However, the output shaft is completely locked up. It has to be an issue with the overdrive unit. I bought the car a couple of months ago and the overdrive never worked. I wasn’t too concerned as I just planned on short distant drives. I wish I would’ve inspected it more thoroughly in hindsight. Could a failed overdrive unit literally lock the transmission up that you know of?

 

Hi,
I had the same problem with my 85. The shift fork was broken.
Couldn´t get a new one, so we welded the old one. Works fine for 5 years now.

 

I had the same problem as well. Broke the 1-2 shift shaft, luckily when it was in neutral. No idea how. I was 600 miles from home and managed to make it using 3-4-od only.
I ordered another shift arm off eBay, but it turned out to be from an early 70's super T-10. The angle of the flats for the shifter plate that bolts on the outside was all wrong. I had to make a new shifter arm for it, and after about 4 tries, I finally got it right. I made it out of 1/4" plate steel, with a sawzall, drill and die grinder. As there were no flats on that shifter arm, I extended the wires and installed an electric proximity sensor that picks up the shifter in 4th gear, and trips a relay to close the contact to enable the OD unit.
There can be absolutely NO play in that arm, or the tranny will lock up and not move. Or it will sit in 1st and not shift out unless you played with ALL the shift arms until something went clunk inside.
This happens when two gears are engaged at the same time.
I've also heard that the planetary gears in the OD unit will seize up on failure, allowing only reverse, and no forward gears, or the opposite, all forward and no reverse.
Frustrating as hell.
The OP needs to make sure that the transmission is absolutely in neutral, before determining what is locking it up. I think that removing the OD unit from the tranny willl tell the story as to which one is seized.