Which T case so i have? casting number 25909

[GregJ77]

Hey guy's so i bought a truck off this kid, (dumb i know) but i got a good price, I'm a cummins guy and not to familiar with the chevy T cases. I know theres 3 different spline types for 1/2 ton 3/4 and one ton? The kid ripped the tag off and the only number on this thing is the casting number on the rear housing. I have 31 splines so is mine the 261hd or 263hd? Any help would be great i just wanna make sure i order the right parts. I also have the inch and a half chains, thanks guys, Greg 2004 GMC 2500HD LB7 DURAMAX ALISON TRANSMISSION.

 

[TheBac]

Moved to Tcase/Axles section

If thats the original Tcase off a Duramax/Allison (or ZF) truck, manual shift will be 261xhd, electric shift will be 263xhd. IIRC, they are the same inside.

 

[GregJ77]

Hey thanks for the reply. I was thinking it was the 263XHD but someone said those aint 31 spline.