98 olds bravada stuck in awd

[muskie1970]

My 98 olds bravada is stuck in awd and started making a pinging sound towards the rear of the vehicle when you start to take off in forward or reverse. Do not hear the sound when you let off the gas pedal amd coast.It almost sounds like it is in awd but not all the way. Just would like some help as far as where to get started. Computer at Advanced only showed I need to replace O2 sensor. No awd light lit up on dash.

Thanks,
Jeff

[Chris Stewart]

I'd pull the AWD fuse then change the transfer case fluid.

This is part of a good post is from Muddog321

If a Bravada(??) then you really should be using blue AutoTrak syn fluid as the GM bulletin states for your full time case same with the AutoTrac 236 cases. Yours has clutch packs in it.

[maxwedge]

Welcome to AF. First of all the bravada is in awd all the time that's it's design, now there could be an issue with the the transfer case binding , requiring either a repair or a reprogram, but it sounds more like a driveshaft noise you are getting, "u" joint specifically, have it checked for the noise.

[Genopsyde]

Bravada is not in AWD all the time. Smarttrak is designed to engage when slipping is detected at the rear wheels, then disengages the front shortly after the slipping stops.

[ericn1300]

Originally Posted by Genopsyde

Bravada is not in AWD all the time. Smarttrak is designed to engage when slipping is detected at the rear wheels, then disengages the front shortly after the slipping stops.

Really? My understanding is that my Bravada SmartTrak is supposed to be AWD all the time. The power shift is 65% rear AND 35% front under normal conditions and can reverse under adverse conditions. The limited slip differential at the rear axel controls cross wheel slipage. I'll check the owners manual after the game.

Go Nevada, win one for the WAC on the smurf turf.

[Genopsyde]

it's possible that it works differently in the 2002+ models as compared to the 1st and 2nd gens.

[Chris Stewart]

The '91-'97 Bravada's Smartrac is engaged in 24/7 with the Viscous Clutch.
The '98's on are engaged electronically...encoder motor and I think an electro-magnetic clutch.

[ShadeTreeJack]

Muskie: Did you ever find the problem? I have one stuck in AWD. It doesn't like to turn sharp and it doesn't accelerate as good as it should. Great in the 6 inches of snow we got last week in Ann Arbor, mi. Yes, i am replying to a 6 yr old post....looking for answers/common issues/repairs done before starting in on it.

[Chris Stewart]

I believe ol'Muskee made that 1st and only post back on '06.

The action still holds today, I'd pull the AWD fuse then change the transfer case fluid.
After or if it comes unstuck, then plug the fuse back in to activate.

Some leave it unplugged until slick roads are anticipated, then plug it back in.

One of the more ingenious ones even made his to be engaged manually.

This is part of a good post is from Muddog321

"If a Bravada(??) then you really should be using blue AutoTrak syn fluid as the GM bulletin states for your full time case same with the AutoTrac 236 cases. Yours has clutch packs in it."

If the device that engages & disengages the AWD, known as an encoder motor, is broken, service work is required.
Search "encoder motor" here for some really good info.