Last post on Feb 05, 2008 at 3:55 PM
You are in the GMC Safari & Chevy Astro
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GMC Safari, Chevrolet Astro, Transmission, Van
#1 of 3 1991 awd drive train issues
Feb 05, 2008 (6:31 am)
New man on the post!! This seems to be a great site for all things astro. Hope someone can help me out.
I recently bought a 1991 astro awd with 208k miles. It's been kept up fairly well. Anyway my question involves the drive train. I replaced one front cv axle as the boot was torn. The issue is when I turn sharply left or right, going forward or backing up, the wheels seem to want to bind up, stop moving etc. Seems to be mainly in the rear although can't really tell for sure. The rear tires seem to slip a bit while going slowly up steep grades, like steep driveways, while turning sharply in either direction.
The mechanic that replaced the axle called a dealer and they said this was normal with this year astro. It doesn't seem right that a truck would be made to do this as normal.
Thought it might be u-joints or the transfer case Other than that the truck runs pretty smooth. Hoping someone can point me in the right direction.
Thanks for any help.
#2 of 3 Re: 1991 awd drive train issues [snowy23]
Feb 05, 2008 (8:00 am)
Within a previous reply (in a different thread), I wrote:
"- Rear end locked on tight corners. Fluid changed and problem went away. Today, we only use Synthetic 70W90 gear oils (front and back axles).".
If they replaced your rear axle with a posi-trac axle then yes, one of the rear tires will dig-in then slip on the tight corners. If they replaced with a limited slip axle then its axle gears are sticking. Ensure thicker Synthetic replacement oil is used.
Hope this helps...
#3 of 3 Re: 1991 awd drive train issues [spike99]
Feb 05, 2008 (3:55 pm)
Thanks for the reply. I meant that I replaced one of the front cv axles not the rear. It most likely has the posi -trac rear axle. I'l be doing a complete fluid change soon and will confirm exactly what type it is. I guess since it's awd, it's like a 4x4 all the time, and they do act a bit funny on tight turns. I have a 79 IH scout and this all makes sense once I thought about it. A local transmission shop also confirmed this behavior. Anyway thanks again.