T-90? T-86?

OK, my tranny case is stamped t-86AA. From what I have read, it probably has the T-90 parts on the inside. So, if I have the main shaft with straight splines, it's T-90 internals, right? Is there anything else to look at inside? If it is T-90, that means ALL the internals are T-90?

 

Mmm, I think first gear is straight-cut on a T-90 and beveled on a T-86 (quieter).

 

Yup. Dead on about the gear. The output shaft on the T-86 is spiral cut splines instead of straight cut splines also. I think the idea was to help first gear mesh a little easier than on the T-90.
If you have the straight cut 1st gear and straight cut splines then you have all T-90 guts. Can't mix and match the parts or you end up with problems. Nickmil.

 

Is first gear the one that slides on the shaft? My schematic doesn't show which is first gear.

 

Using the schematic in the tech article, #23 in FIG. 208. Is that first gear?

 

Looking at the picture, the sliding gear (#23) operates both 1st and reverse.

 

Looking In The Tranny, Nothing Looks Real Bad. The Syncros Look A Little Rounded Along With The Edges Of The Gears. The Tranny Goes Into 1 St And 2 Nd Fine, But Will Not Go Into Third (no Matter How Hard You Pull). Any Ideas?