Jeep grand cherokee quadra drive
The Jeep Quadra Drive systems have a limited slip differential in the transfer case as well as the front and rear axles - which allows you to run all wheel drive on all surfaces. This matters because without limited slip capability your transfer case & axles would break.
Have your transfer case and axles serviced by a dealer, really a real dealer for Chrysler Jeep. These diffs and transfer cases can use unique gear oils that you don\'t want to mix up with regular gear oil.
That howling, clunking, grinding noise is your dog-clutches slipping (as designed) as you go around the corner.
Additional Details below:
So what\'s the Diff?
All differentials are is a way to allow for different wheels to travel different distances on the same vehicle. What-he-say? Yep, when we turn a corner all 4 wheels go a different distance around that corner... oh yeah well everybody knows that. Think about it, your making that hard left turn at your favorite Fast-Food joint; your left front wheel is 2 feet away from the curb, but the back left wheel rubs the curb... why?
As you make that 90 degree turn, your left back wheel travels 4 feet, your left front wheel travels 6 feet, your right rear wheel travels 7 feet, and your right front wheel travels 8 feet.
Ok you say, what\'s the big deal? A couple feet slip here a couple of feet slip there... Well remember your sticky rubber tires on dry asphalt don\'t really give very much and u-joints, axles shafts, and even pinion and ring gear damage can occur. Fortunately for us, Leonardo DaVinci (yeah really) saw this problem coming and designed the Open Differential. There are mini-gears inside your open differential that allow for that slippage, these mini-gears are called spider gears. Problem is when your in snow, ice, mud the spider gears of the open diff allow all your power to go to the wheel with the least traction (and your stuck).
Ok let\'s put another powered axle up front and call it 4x4. Umm no.
A normal 4x4 is not really true four wheel drive. At best it\'s the worst 2 wheels you\'ve got - driving you forward. Until both wheels on the same side are in a ditch, and your stuck.
Well what the heck Leonardo? I want something better than stuck!
The old-time dragster dudes of the 50\'s & 60\'s agreed with you and they welded those little spider gears together for true positraction across both wheels. Ever been close to a big monster truck in a parking lot and heard its tires chirping around the corner? Or an old Jeep crow-hopping it\'s way around a corner - Letting out little tire noises (like "erp" "erp" "erp")?
That\'s because these 4x4\'s have been modified to not have any differential action. None. This is great in a 1/4 mile dragster race or a mountain climbing rally car. A locked front differential can (and most likely will) cause you to crash... not good for daily drivers.
You\'re in luck, the Limited Slip Differential (LSD) has clutches instead of spider gears, which engage as wheel slippage increases. Subaru and Audi are 2 companies that really brought this to market with All Wheel Drive decades ago. Jeep and other SUV/Pickup manufacturers have utilized clutch-based LSD\'s as well. Clutch-based LSD\'s however, have a limited lifespan and can require special gear oils. When Clutch-based LSD\'s fail, they basically become an Open Diff.
Automatic locking differentials were brought to market in the 70\'s & 80\'s by companies like Detroit Locker, and these engage a fully locked set of gears as soon as any slippage occurs. Problem is it can become very difficult to steer, at all. Forget about U-turns, just go around the block. And while your at it, stop and pick up another set of tires because it will feel like you are dragging your outside tires around every corner.
Jeep and Daimler-Chrysler developed another type of LSD that utilizes a small hydraulic pump to engage a set of clutches and gears, which lasts much longer than traditional LSD\'s. It was called a Gerodisc differential, and it worked fairly well. Not as much traction as a full locker, but good LSD performance. The problem was the Gerodisc couldn\'t control itself in the car-washes, and would build-up pressure as the tires slipped over the soapy rollers, and launch the Grand Cherokee across the car wash. Yeah, it was freaky. So freaky that the National Car Wash Association of America (yeah they have an association, who knew?) prohibited all Grand Cherokees. Look it up.
The King Daddy of differentials is the selectable locker. These little gems are very expensive, but you get all the benefits of both the open diff for maneuvering, and lockers for traction only when needed.
So that noise, while it may not spell imminent doom, surely ain\'t good.
Jan 02, 2014 |
Cars & Trucks