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1997 AWD guide for idiots

785 Views 5 Replies 5 Participants Last post by  tungtide
Can someone please explain to me how the AWD works on a 97? I do not have an engage button, or lever, or lockout. I’m assuming this means I have full time AWD with 3 diffs working to power all wheels with (perhaps) the ABS limiting individual wheel slip?
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Wheel sensors engage the AWD when the rears spin faster than the fronts. For an over simplification. Many parts need to function to make it happen. So many Astro owners change out the 136 transfer case for a 233 then install a manual shifter to obtain 4x4. So many options you will have to search and read. I kept my AWD 136 transfer case (for now) I installed a cast iron front differential with a LSD locker. I have several 233, but I’m. Not in a hurry to go 4x4. If the sensors and computer work the AWD is great especially in snow. Someone who knows more will be along shortly.
There are no sensors for the AWD, it's a full time viscous clutch based system.
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Yup. on the 97 it's 60% power to the rear, 40% to the front all handled by viscous clutch packs.

They went to encoder motors in late 98 and all 99's

ABS is for braking only.. apply brakes hard and if one of the wheels stops spinning (slips) while the others continue to roll, then ABS pump pulses the brakes.This part is handled by the wheel speed sensors.

FYI I'm pretty sure ABS/AWD/cruise are on the same fuse in the 99+ vehicles. I'm sure someone will correct me if I'm thinking incorrect on this.
Edit to remove post…. Dchan posted as I was typing…. Was saying the same thing.
Thank you gentlemen for the correction.
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