4WD Won't engage, '96 K1500 Suburban

[LIVE RUST]

Are you sure the fronts are spinning in low?

['72 Chevy Suburban]

Originally Posted by LIVE RUST

Are you sure the fronts are spinning in low?

I am pretty sure. I felt a clunk and heard the extra whine that is usually associated with the fronts turning and I didn't take it above 30MPH because of the whining. It had the same feel as 4LO. The only thing that I don't remember was whether or not the light stayed on in 4LO. I googled it at lunchtime and came up with a pretty interesting link. I am going to check this stuff out this weekend: http://autorepair.about.com/library/a/1/bl378.htm

Do you think that this system and troubleshooting would apply to my truck? It sounds like a similar setup and it goes back to your earlier comment about a leaking vacuum hose.

Thanks,

[DirtyLarry]

These electric shift junkers have 4 main components and 10 miles of wiring to go wrong.

1) Control head (button assembly)
2) Tranfercase control module (TCCM) - under the dash
3) Encoder motor - located on the tranfercase
4) Front axle disconnect – located on the front axle

If you actually hear and feel a clunk and the tranfercase will actually go into low range but you have no front wheel action, then you have a problem with the front axle disconnect. Unlike the link you posted regarding the S-10 Blazer, the full size rigs did not use vacuum to engage the front axle. 1996 was the first year for a fully electronic front axle disconnect from the previous thermal axle disconnect. It sounds like that or the wiring to it could be your culprit.

Click this link for the ultimate fix for front axle disconnect issues. http://www.4x4posi-lok.com/app_chevy-k.html