4 Wheel Drive/SUVs/All Wheel Drive

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Expert: - 1/6/2012


Question
I have a 1998 Oldsmobile Bravada with the Smarttrack all wheel drive. Ive haad this vehicle for a year now and im kinda in the dark about exactly how the smartrack system works. Do the front tires only engage if the back tires are spinning or do they automatically start pulling at a ceritan rpm? Also for the last few months if i turn to the left or to the right to slow or to sharp i have a popping noise coming from the front of my vehicle. I have been told that its the diff slippin but honestly i dont think thats what it is. I was just wondering if you could clear this up for me and a posible way to fix it.

Answer
Dillon,

Normally full time or all wheel drive vehicles only apply traction to the front, or rear of the vehicle (depending on the type of transfer case) and when the vehicle detects loss of traction, power is applied to the non-driven axles.
If you are having this type of noise from the front end, I would doubt very seriously if it is the differential.  I would check out the axle cv joints as this is the most common failure in this type of drive system.  
If it was a differential, then the noise could occur intermitantly, or fail completely, but not just in turns.  
If it is a cv joint, then it not a real difficult fix and takes about 2 hours per side.  I would take the Bravada to a reputable transmission shop and have it checked, or get an estimate for repair.
If you want to trouble shoot, or repair it yourself, then I would purchase a repair manual at a local auto parts store.  They have step by step instructions on trouble shooting and repair along with pictures of the components, and a list of any special tools needed.

Carl

4 Wheel Drive/SUVs

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Carl Brandt

Expertise

Will discuss suspensions, lifts, lockers along with tire suggestions. Trail ratings and possible requirements needed for specific type of trails. Safety equipment and what you should carry with you. Certified off-road instructor. I am not a mechanic, and 4-Wheeling is a hobby, so if I can't answer a technical question it is due to my mechanical knowledge being related to vehicles that I have owned, or have worked on. I do not have manuals on all vehicles.

Experience

40 plus years of 4 wheeling in a variety of vehicles. At the present time, my major off-road rig is a 94 Jeep Wrangler with a spring over and a 1 1/2" suspension lift. This gives me a total lift of 7" or so. I have lockers front and rear. I have removed the track bars, and sway bar for maximum articulation. I am running a stock 2.5 ltr 4 cylinder with a Jacobs ignition along with a cold air high flow filter. It has 4.56:1 gears with a Dodge NV4500 transmission along with a 3.8:1 Atlas II transfer case. This gives me a final ratio of 105:1 in low gear/low range. Other vehicles I own, are a 96 Ford F-250 with a 6" lift, posi rear end, 36" Hummer tires, 5 speed with a fuel injected 460 ci engine, an 87 Samurai with an 8" lift, Ford 9" rear end with a spool, Chevy Dana 44 front end with an electric locker, 5.88 gears, 16% reduction in high range and a 6.5:1 low range with 35" Baja Claws, and a stock 2003 Grand Cherokee Overland. Trails I have run are the Rubicon (10 times), Dusey Ershim, Fordyce Creek trail, McGrew trail, several trails in Moab, Utah along with local monthly runs.

Organizations
Lost Coast 4x4's Cal 4-Wheel Corva UFWDA Blue Ribbon Coalition

Education/Credentials
Certified off-road instructor - Certificates in engineering/electronics

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