ID 1966 Scout 800 Transmission

[Tyler]

I'm looking for help IDing my transmission. I believe it's a T-18, and not a T98 like the gear cover says, but any wisdom you guys could give me would be greatly appreciated. I'd like to rebuild this transmission myself. It looks pretty good except for that first large gear. The clutch is definitely shot, so I'll be replacing that at the same time.

What parts am I going to need for the rebuild? What's my gear ratio on this, or how can I figure that out? Is there a better gear ratio I should change it to while I'm at it?

1) Scout 800
2) 1966
3) 4x4
4) 4 speed
5) Not sure of the axles
6) 152 4 cylinder
7) which ignition system variation?
8) 2 tanks
9) single cylinder
10) Supposedly it was a military vehicle on the Yankton air force base.

 

[Hondo]

What is the history of this transmission, did it come out of the 66 Scout 800? Was it running? They came with 3 speeds or 4 speeds. Looks like the one in your pictures is short a gear for a 4 speed. Pictured is a wide T19 4 speed, which is very similar to the T18, but has synchros on first gear whereas the T18 does not. Reverse on a T18 is also to right and forwards, T19 is to the right and backwards. The rectangular opening on the top of yours also does not indicate a t18 or T19. To determine gear ratios is a matter of counting how many turns of the input shaft it takes to turn the output shaft one full revolution.

 

[Robert Kenney]

His photo is of a 4 speed. First and reverse share the straight cut large gear.

 

[Hondo]

Ok, never had the top cover off the T18 in my 72 Scout. From what I've read, wide Scout T18s (6.32:1 first gear) are pretty rare. If it is a T98, it should have a very deep 6.39:1 first gear.

 

[Tyler]

Ok, never had the top cover off the T18 in my 72 Scout. From what I've read, wide Scout T18s (6.32:1 first gear) are pretty rare. If it is a T98, it should have a very deep 6.39:1 first gear.

I counted the turns and got the following. First gear was 5:1, second 2:1 third 1.5:1 and 4th is 1:1.

Is this gearing going to be ok for daily driving? My first gear will be to be replaced, so would 6.39 be better?