H3 4WD servo motor
 

Hi,
I’m new to the forum and hope this is where to ask questions. I have a ‘07 H3 with 89K miles and it won’t engage the 4WD differential and I think the servo motor is bad.
Where is it located and is it difficult to replace. I don’t have the money for the GM dealer to repair. Any suggestions.

H3 differential servo motor.
 

I have a ‘07H3 with 89K miles and the 4WD differential will not cycle and I think the servo motor is not working.
Where is it located and how difficult is it to replace?

Check inside the glovebox? :rolleyes:

what you ask for should be on the transfer case not on the differentials. some have removed them and cleaned then re-greased it and put it back. sometimes it just need to be replaced. not too hard to access looks a bit like a wiper motor stuck to the side of the transfer case.

I MOVED and merged your duplicate question from the New Member section to this one. Works like this. ALL H3 questions go in the H3 Section, ask it once and wait for replies.

What you are looking for is the 4WD Transfer Case Actuator and like bronxteck said it is mounted to the Transfer Case, looks like this (#12 in diagram). Check the wiring to it and clean both sided of the connector with CRC Electronic Cleaner before you replace what ain't broke.
https://cimg5.ibsrv.net/gimg/www.hum...b9cd43bc00.jpg

https://cimg5.ibsrv.net/gimg/www.hum...5a2574b8f6.png

It would also be helpful if you describe what it does when attempting to change the T Case from Hi to Hi Lock or Lo Lock, when it stopped working/if it ever did, and which Model H3 you have.

I am also going to ask.... have you read the owners manual on how the T Case buttons work?

ACTUATOR, Transfer Case Shift Control 19300596

https://cimg1.ibsrv.net/gimg/www.hum...35eb319111.jpg

H3 servo
 

Thanks for your help I really appreciate the time and effort. Not much support available these days since GM left all of us hanging when they pulled the Hummer line!!!
In my opinion one of the all time great 4WD....I’m an old timer from the the Dodge Power Wagon days and the International and can’t forget the old CJ 5 Jeep’s.....
thanks again.
Phil Polaski
Cincinnati, OH