Four wheel drive low will not lock in

BTOLER

MEMBER
2007 GMC SIERRA
5.3L
V8
4WD
AUTOMATIC
143,000 MILES

When I turn the four wheel drive knob out of four wheel drive high or low, it kicks out hard; good jolt. Is this typical? Thanks

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Thursday, April 19th, 2018 AT 4:01 PM

5 Replies

KEN L

MASTER CERTIFIED MECHANIC
48,420 POSTS

You need to be stopped to change range gears. Do you feel a jolt when it is stopped? Please let me know.

Cheers, Ken

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Sunday, April 22nd, 2018 AT 11:14 AM

BTOLER

MEMBER
29 POSTS

Yes sir, both the high and low 4AWD coming out of 4WD a jolt.

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Sunday, April 22nd, 2018 AT 12:28 PM

STEVE W.

MECHANIC
13,597 POSTS

I run into this now and then if the front axle is not disengaging properly.

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Sunday, April 22nd, 2018 AT 6:09 PM

KEN L

MASTER CERTIFIED MECHANIC
48,420 POSTS

Nice, that sounds like it to me as well. Please let us know if this fixes it.

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Monday, April 23rd, 2018 AT 12:33 PM

STEVE W.

MECHANIC
13,597 POSTS

Check to be sure the front actuator is actually operating properly. As they wear they do not pull the release collar fully. Then as the vehicle moves you get some torque wrap in the drive line and "bang" as it finally releases. The other issue can be that the splines get twisted if someone tried to engage or disengage the four wheel drive when the tires are spinning. Both will cause the front interlock to bind.