# 4 wheel drive not working

**URL:** <https://community.cartalk.com/t/4-wheel-drive-not-working/24382>\
**Category:** Maintenance/Repairs\
**Created:** [January 4, 2009, 11:42pm UTC](https://community.cartalk.com/t/4-wheel-drive-not-working/24382 "2009-01-04T23:42:37Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![chevyblazer98](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@chevyblazer98](https://community.cartalk.com/u/chevyblazer98)\
**Post date:** [January 4, 2009, 11:42pm UTC](https://community.cartalk.com/t/4-wheel-drive-not-working/24382/1 "2009-01-04T23:42:37Z")

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why does my 98 chevy blazer shift from 2 wheel drive in to 4 wheel drive while iam driving??

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**Author:** ![pleasedodgevan](https://avatars.discourse-cdn.com/v4/letter/p/51bf81/32.png) [@pleasedodgevan](https://community.cartalk.com/u/pleasedodgevan)\
**Post date:** [January 5, 2009, 3:38am UTC](https://community.cartalk.com/t/4-wheel-drive-not-working/24382/2 "2009-01-05T03:38:03Z")

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How do you normally shift it into and out. Is there a lever or a switch?

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**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\
**Post date:** [January 5, 2009, 3:00pm UTC](https://community.cartalk.com/t/4-wheel-drive-not-working/24382/3 "2009-01-05T15:00:53Z")

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This may be vacuum activated like earlier models. If there’s a vacuum leak it may be causing the vacuum activator to switch it into 4wd without you activating the lever.