I have a '01 2500HD Ext Cab Short Bed 315/75-16 8.1L Allison


I took it in the mud over the weekend...While out there it got stuck in 3rd gear and i had a hard time getting it into reverse...


Now everything is normal when I first start it...After everything gets warmed up...engine to noraml temp and when the trans hit about 160-170 deg. the shift indicator dissapears and it get stuck in 3rd gear again no matter where i put the shifter...except N R & P but R is a pain the get into...


Can anyone help me with this ?


Thanks in advance, Artie

nsbu switch on side of trans, gaurenteed (sp*)

Do you have a suggestion as to where I should get it from ?


And also, What does NSBU stand for


Thanks, ArtieEdited by: 2500HD2001

http://dieselplace.com/forum/forum_posts.asp?TID=3279&PN=1

Try this link, Transmission Control Module. Me thinks "NSBU" stands for neutral safety back-up switch.

arite, www.gmdieseltech.com (http://www.gmdieseltech.com)


Nuetral Start Back Up switch


where in MI is pinckney?

its 15 miles west of ann arbor


Thanks, Artie

artie, I dont have it yet, but working on a step by step on changin one

The black unit on the right just behind the torsion bar. The newer styles are no longer black but tan. Stands for Nuetral Safety Back Up

http://www.uscom.com/~hoot/cars/duramax/gmc/allison/allisunder.jpgEdited by: hoot

Artie


I bought one from a Detroit Diesel/Allison dealer for less than the Chevy Dealer


Good Luck