Won't Go Into Low Range, 2005 1/2 Ton

[bfr57]

Have an 05 Avalanche that won't go into low range. When I push the low range button, I get some very loud clunks from transfer case as if it's trying to engage, but eventually cycles back to 2 high. I can get it into 4 high no problem. Any suggestions?

[RaddHazzard]

Maybe your transmission has to be in neutral to shift into 4L?

[Big Whiskey]

Maybe your transmission has to be in neutral to shift into 4L?

 

Yes, that's the first thing I thought too. You can go from 2HI to 4HI on the fly, but you have to be in Neutral to go into 4LO.

[bfr57]

It was in neutral. I usually don't drive the truck, but did this weekend and noticed the Auto 4WD light was on, so put it back into 2HI. When I did this, the light said 2HI, but truck was in neutral. Tried it again once I got home on safe ground and did the same steps and it would catch in 2HI, but pop out once gas pedal pressed. Have to be in AUTO 4WD in order to drive. Still no low range, just get the loud clunks trying to engage. Encoder motor?

[ColoradoSkiCountry]

You also need to be moving forward at about 2-3 MPH, in neutral when pressing the 4-LO button. Did you try that?

 

 

It was in neutral. I usually don't drive the truck, but did this weekend and noticed the Auto 4WD light was on, so put it back into 2HI. When I did this, the light said 2HI, but truck was in neutral. Tried it again once I got home on safe ground and did the same steps and it would catch in 2HI, but pop out once gas pedal pressed. Have to be in AUTO 4WD in order to drive. Still no low range, just get the loud clunks trying to engage. Encoder motor?

[bfr57]

I've had this truck since new and shifted the 4x4 many times, and there's definetly a problem, not operator error....

[nickvrebel]

sounds like something is not allowing your tranfercase to shift properly, encoder motor is a possibility, do you have any "service 4wd" message or anything like that?

[bfr57]

About three months ago my wife mentioned the Service 4WD came on while driving, but went out after a re-start. Hasn't been back since.

[ColoradoSkiCountry]

It may have stored a code with that Service 4WD message, have you checked on that?

[bfr57]

No, haven't checked for codes, but I've also replaced the battery since then....

[bfr57]

Fixed it!! Bought a new motor from Autozone, followed the directions, and works like a charm. The only thing I had to do is turn the shaft on the transfer case to align with the female splines on the motor.

[ColoradoSkiCountry]