Chevy & GMC Vans

First off let me say thanks to the members of this forum who have helped me out with my craziest rear end problems a few months back.

The van made the move from Illinois to California with out a problem towing a close to 4000lb trailer and the full family inside hehe.

Now on to my problem. My front drive shaft ate complete crap, meaning the u joint portion, I think I need a new drive shaft since it seems like its the part on the ujoint carrier thing thats broken.

My real question however is. I have searched from top to bottom and never really saw a direct answer.

If I have a 1996 Astro with the mechanical viscous transfer case, can I drive around with out my front drive shaft with out damaging anything for a little until my new one comes in or is that a no no.

I don't drive much just to work, school, and back on a daily basis but this is my main means of transportation.

Thanks for all your help,
Mike

For a short time and shorter distances you will be ok. Just remember that without the front shaft in, your an WILL roll downhill unless you use the parking brake. The viscous coupling will slip over time and that is why it rolls.

So Dean, you're saying that the parking pawl wont lock the driveshaft as in two wheel drive?

Ok I removed the front driveshaft and as I thought the thing is toast hehe. The van runs really smooth now in rwd mode, and I should have my replacement in 2 - 4 days.

And yes with the type transfer case I have, the one with the viscous coupling and the viscous liquid in it the car rolls very slowly down a hill of course depending how steep the hill, here in Cali pretty much everywhere :p but with out a front drive shaft the viscous coupling will slip a bit since it doesn't have enough preload just from the rear wheels. At least that's how it was explained to me .

Once againt thanks for the awesome info guys.

Smiliesafari wrote:So Dean, you're saying that the parking pawl wont lock the driveshaft as in two wheel drive?

That is correct. Seems weird but it doesn't lock.

Smiliesafari wrote:So Dean, you're saying that the parking pawl wont lock the driveshaft as in two wheel drive?

On a 2WD the parking pawl locks the tranny which is directly connected to the drive shaft. If both the rear wheels are on the ground, the van will not be able to roll.

On 90 to 98 AWD van the tranny is connected to a transfer case and THEN the drive shafts. The 90-98 transfer case uses a viscous coupling to connect the front and rear drive shafts. It uses clutches and fluid to connect the two. This allows the front to turn at different speeds than the rear making steering easier on dry roads.

So, since the front and rear drive shafts are not mechanically connected, if one is disconnected the transfer case will turn against itself causing the van to roll. The same reason an automatic tranny needs a parking pawl.

Thanks. Even at my age there's still a lot to learn.

I'm reading all the posts with lots of interest. I've never had any of my AWD tranfer cases apart in all the ones I've owned. Hence I don't know whats inside !! My Safari is a 97 and if I'm to understand this correctly inside the case there is a "limited slip" clutch pack similar to the rear axle except turned front to back or is it like a "detroit locker" where it's all mechanical with overrunning ball bearings ? My question is if it's a clutch pack wouldn't engine torque break loose the clutch pack and burn out ?

Thanks,
Terry

Well, after searching the net I've answered all my questions....I have too much time on my hands !!