99 Suburban transfer case motor cracked!

[Joe Bltsphlk]

While finishing up a Y-pipe replacement job, I was looking around underneath my sub to see if there might be a special reason why the exhaust pipe decided to break off right at the exhaust manifold flange on the passenger side (for example, are the engine mounts broken), and I noticed that the flange on the transfer case shift motor is cracked! Check out the area around the top bolt in this picture. Anyone ever heard of this failure before? I'm about ready to order a replacement, and I'm wondering if the ACDelco 12474401 is really worth the $367 compared to the Dorman 600-901 for $137. Any experience with Dorman? I've seen a few negative reviews.

[Joe Bltsphlk]

This might not be a good sign. Plastic shroud over the motor was cracked, right out of the box.

Got another question: directions with the new motor say that it's shipped in neutral position, and to put the car's transfer case into neutral. Can I do this manually (with a wrench)? Because I sure can't do it using the broken motor.

[j cAT]

Originally Posted by Joe Bltsphlk

This might not be a good sign. Plastic shroud over the motor was cracked, right out of the box.

Got another question: directions with the new motor say that it's shipped in neutral position, and to put the car's transfer case into neutral. Can I do this manually (with a wrench)? Because I sure can't do it using the broken motor.

the encoder does come in neutral. this can not be moved because the brake in this prevents moving. the transfer case fork can be moved . try to move fork most have had success.

return broken new part ... where did you buy this ?

[ASJT3]

Originally Posted by Joe Bltsphlk

This might not be a good sign. Plastic shroud over the motor was cracked, right out of the box.

Got another question: directions with the new motor say that it's shipped in neutral position, and to put the car's transfer case into neutral. Can I do this manually (with a wrench)? Because I sure can't do it using the broken motor.

What I've done before is to pull off the plastic shroud, then unscrew the motor. You should be able to rotate the female socket on the encoder to match the transfer case position. Then reassemble motor/shroud and attach to t-case.

[Joe Bltsphlk]

Originally Posted by j cAT

the encoder does come in neutral. this can not be moved because the brake in this prevents moving. the transfer case fork can be moved . try to move fork most have had success.

return broken new part ... where did you buy this ?

It came from Amazon, and they replaced it with a good one without any problem. I was able to turn the shaft coming out of the transfer case with a wrench. It sort of moved one click counter clockwise, and that lined up perfectly with the encoder. When the car started, it was either in 4-Hi or it put it into 4-Hi, and I was able to shift it to 2-Hi. At that moment, I noticed that the plate is cracked right at two of the bolts! I'm pretty sure this is my fault, because thanks to my deaf ears, I didn't hear the torque wrench click at 15 ft-lbs when reinstalling the three bolts, so I bet I over-torqued them...sheesh. At least the "service 4WD" light went out. Maybe I can put a clamp up there.

I haven't take apart the old one yet, but I did find a lot of dirt between the plastic gasket (which goes between the transfer case and the motor's gearbox, and btw had to be reused) and the gearbox. Also, there's some kind of corrosion growing out from between the two halves of the gearbox, which probably caused the failure shown in my original post.

Then I changed the fluid (for the first time, ~125,000 miles) and was happy to see that it was not full of sludge; it was clear red. The new fluid, ACDelco 10-4017 Auto-Trak II Transfer Case Fluid, is blue.

Thanks for your help!