Front drive shaft spins when in 2H

BLANKFORD101

MEMBER
2000 CHEVROLET TAHOE
5.3L
V8
4WD
AUTOMATIC
139,000 MILES

When I slowly back up I can feel a vibration. Put it on a lift and it turns out that when It is in 2WD 2H it is spinning the front drive shaft. I can put it in 4WD and the front transfer case engages and works. Comes in and out of 4WD fine. Curious if the Transfer Case shift motor needs to be replaced or is it an other issue? Everything else works.

Saturday, July 20th, 2019 AT 9:13 AM

5 Replies

KASEKENNY

MECHANIC
18,907 POSTS

Hi Blankford,

This sounds like a possible shift motor but it could also be something inside the unit not releasing 4WD. However, I would suggest to just remove the actuator and see if you can manually shift the transfer case and see if you can get it into 2WD. If you can then the actuator is your issue.

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Sunday, July 21st, 2019 AT 4:36 PM

KEN L

MASTER CERTIFIED MECHANIC
54,144 POSTS

Yep, the front drive should not be spinning so it sounds like the encoder motor is not working right here are diagrams and instructions to help you fix the problem. Check out the diagrams (Below). Please let us know what happens.

Images (Click to make bigger)

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Sunday, July 21st, 2019 AT 4:39 PM

BLANKFORD101

MEMBER
2 POSTS

KASEKENNY1, Can you clarify what you mean by actuator. What is it and how to remove it?

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Monday, July 22nd, 2019 AT 10:50 AM

KEN L

MASTER CERTIFIED MECHANIC
54,144 POSTS

The encoder and actuator are the same thing.

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Monday, July 22nd, 2019 AT 11:00 AM

KASEKENNY

MECHANIC
18,907 POSTS

Yes. Sorry. I meant to include the same attachments that Ken did. Saved them to my computer and forgot to attach them. Other OEMs call them actuators but it is what Ken attached to the first post. Thanks.

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Monday, July 22nd, 2019 AT 11:33 AM