APDTY 711231 4WD Transfer Case Motor Encoder Ring

I had the famous service 4wd message. I started by swapping the dash switch. While that got me a new switch with lights that worked, it don’t solve the problem. This part did. No more random shifting, no more inability to shift, no problems. It’s nice to have my truck behave. If you can swap the encoder motor, you can change this. Dropping the front driveshaft was easy. Index the shaft, mark everything so you can line it back up and drop it. It will take longer to remove and reinstall the encoder motor than to replace this part. Pull the encoder motor. All of this is available on YouTube to watch. Don’t overtighten the torx screws, I broke one and had to drill and tap it. One last piece of advice. I use loctite on u-join bolts and then torque them to spec. Cheap insurance. Overall I’m very pleased. I should have done this a year ago.

The sensor was easy to install. Was able to do it myself and saved a lot of money. I had been getting a "SERVICE 4WD" intermittently for a year or more, then it came on and stayed on. The new sensor took care of the problem.

Ok I spent months reading reviews trying to resolve an issue with my 04 GMC. Hopefully, this will save time for someone. My four wheel drive gained a mind of its on like a wild mustang. I might start the old girl up and it would be in 4 lo, or 4 hi, or she may just accidentally be in 2 hi (leading you to believe the problem had mysteriously resolved itself. Sometime you may not get a lift at all. Regardless of where it was (unless it didn't light up at all) you could always press 2 hi and it would go there and stay there until the next time you put her in the stall. Then she got to where you couldn't change it at all. Once in 2 hi, there was no going to 4lo, etc. and the "service 4WD" light began coming on in the dash. I tried a few other things first (reviews are so misleading sometimes) like an actuator (easy to replace but was 60 bucks and she was still contankerous. Tried the selector switch (no luck there either, save your money). Finally caved and got the 39 dollar encoder ring and my worries are over! Now I'm just going to say that it was probably close to 11 pm before I decide to attempt this and a word of advice.... don't wait until you are tired or cranky! The removal process was straight forward and easy as anyone could ask for! Then removing the couple torx screws and replacing the ring itself, piece of cake also. Now.... it was after midnight and I had dirt in my eyes and lining that little spline back up to the transfer case had me just about as close as ever before at just putting the old girl out of her misery and sending her to her grave. All in all anyone can likely do this little job and save money from purchasing a new motor with the ring inside it. Just don't wait till late at night or your tired and pay attention to detail with the position of the spline on the transfer case verses the motor itself. Good luck.

Do not buy if you have a 2500HD with an Allison transmission, it will just stay in 4lo

Works great. I did not completely remove the drive shift, I just slid it off enough to get the yoke out of the way. Definitely mark your gears before removal, it will save a lot of time. I flipped mine over and the gear fell out before I had the chance to mark it and it was a pain, turning it one tooth at a time, getting back aligned.