I purchased a World Class T5 transmission earlier this week for my 1963 Chevy C10. My other T5 had the main shaft bearings go so I decided to upgrade to a WC T5 instead of fixing the Non-WC T5. The new T5 needed the driven gear on the output shaft swapped so I could get the correct speedometer readings for my truck’s rear end gears and tire height.
After pulling the tail housing all apart, swapping the driven speedometer gear, and trying to put the tail housing back on, I was confronted with a problem that wouldn’t allow the tail housing to go all the way back on. This left about a 1/2 inch gap between the main housing of the T5 and the tail housing.
After nearly 8 hours fighting my T5 transmission tail housing, I finally figured out what was wrong. I found a thread on another site where a guy said he gave the fifth gear assembly a light smack towards the driver side of the transmission and it all popped into place.
I tried this but with no luck, and am not comfortable hitting on the transmission too hard even with a rubber mallet.
So I started playing with the shaft on the on the opposite side of 5th gear which connects to the 5th gear assembly, and discovered the shaft was pushed in towards the front of the transmission. This was causing the 5th gear assembly to lock into a funny position. I pulled back on shaft (pulling the shaft towards the rear of the transmission) and it all freed up.
Once I tried putting the tail housing back on everything went smooth!
Apparently it puts fifth gear into a weird position causing it to hit the side of the tail housing. This needs to be all freed up in order for everything to fall into place.
I hope this helps others with this problem who might find post in the future. There isn’t a lot of posts about it on the internet.
You can reference my thread on the 67-72chevytrucks.com forum here: