Have 4 high but no 4 low

[05tahoe556]

So I just picked up this 2005 Tahoe lt 4x4 a few weeks ago. Everything seemed good with it on the test drive. I put it in 4 high and it engaged in and out no problem and no service lights on. I didn't even think to check low if it went in high no problem. So fast forward to 3 days ago. I tried to use 4 low when pulling my buddies truck out and it would just flash for a bit then just go back to high. Tried in nutrual stopped ,slow roll, and with engine off. You could hear it and fell the truck bump a few times as it tried to. It didn't show service 4wd lights or anything just wont complete the shift. Tried fresh t case fluid with the gm auto track II still nothing. Cleaned the ground conections under the truck they are good. Even tried to reset the computer by unhooking the battery. Nothing has worked. The t case isn't making any funny noises or having any issues with auto 2 hi or 4 hi. What do yall think it could be?

 

[rockenthebowtie]

I know you said you tried it in neutral but were you at a complete stop thats the only way its designed to engage into 4 low

 

[05tahoe556]

Yeah full stop nuetral several times just makes the noise from the encoder motor like its tring then just goes back into where ever i had it either 4 high or 2wd. Tried rolling cause it said as long as its under 5 mph in nuetral in manuel. No luck no mater what I've tried.

 

[rockenthebowtie]

Sounds like it may be the ecoder motor actuator sensor.. are you good at taking stuff apart and putting it back togther

 

[rockenthebowtie]

If you get the sensor I can walk you thru it but your going to need to post pics and I can walk you through it step by step

 

[05tahoe556]

Yeah as long as i know what to replace i can do it

 

[rockenthebowtie]

Ok you'll need to go to the dealer and buy the transfer case encoder motor actuator sensor.. Once you get it let me know and I'll walk you through it

 

[05tahoe556]

Is there anything else I could try before dropping cash on an encoder?

 

[rockenthebowtie]

You don't need the whole actuator just the actuator sensor there not very expensive.. and no not really