transfer case- 91 different from 93?

[gmcturbo]

i blew my transfer case and have found a few used ones for sale. now im getting conflicting stories from many people. do i need one out of a 93 (i got a 93 ty) or will 91 work. i thought i saw that only a ty will work in ty. whats the difference (if any). the reason i ask is because ive found some cheaper 91's and would get it if for some reason it would work.

thanks-

 

[jeremysyty]

I think the output shafts are different lengths/splines from the sy tranny and ty tranny...

 

[Loeryder]

Sy transfer case has 27 splines on the outpuit shaft
Ty has 32 I think.

My numbers may not be 100% but thats the only difference.

 

[gmcturbo]

ok cool, i guess ill just take my driveshaft with me to see if it fits on

 

[Captain Morgan]

I was also told by someone who had some side by side say the Syclone case itself was actually longer???

but yes, the output shafts are different, the Sy has a smaller, lower count spline and the Tys have a larger, high count spline.

I believe there is one internal difference too, but I cant recall what it is.

 

[Tommyquest]

I believe there is one internal difference too, but I cant recall what it is.

Sy case is 3 pinion planetary, Ty case is 4

 

['JustDreamin']

Anybody know how that compares to the Astro / Safari / Bravada cases?

From looking at rebuilders sites, I know the A/S/B tcases also vary by year (rear output shaft 27 or 32 splines) and I think the front flange also is different by year (2 different diameters). And the chain for the 'Stro case is listed as being different than the others (why I dunno).

Anybody got any further information?

'Dreamin'

 

[gmcturbo]

im interested in this as ive found a few bravada ones also. but from what ive heard, its the same if its the same year. maybe someone can chime in here.