Trouble Shooting

[Rschap]

I could use a little help troubleshooting. I have a 99 classic, K3500 that I blew the tranny on 2+ years ago. I finally got around to rebuilding the tranny, getting it reinstalled last week. During the test drive it acts like it’s in 4 low as far as shifting and power but the front wheels aren’t powered up and it should be in 2wd. It’s shifting through to 4th before I’m going 20mph when the selector is in 2 high. I shifted back and forth between 4 low, 4 high, and 2 high and got it to shift normal on a drive and it was working great but now it’s doing the same as before.

I did change the fluid and refilled with Valvoline Max Life Full Synthetic Dexron VI when I reinstalled it in the truck. I made sure all the connectors were reconnected.

 

[Schurkey]

Sounds like a transfer case problem/electrical control system, rather than a transmission issue. Concentrate on the transfer case and it's electric-shift system--wiring, fuses, encoder motor, etc.

A scan tool will likely be a big help.

 

[Rschap]

This is the way I am leaning, thank you. I'm having a little trouble identifying the case as well, I think it's a BW 4401 but need to confirm incase I need to order parts. Any help would be appreciated.

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[Rschap]

Well, I believe I found my issue. I'll be rebuilding the T case now. I appreciate the feedback.

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