The more resistance the engine sees, the more torque it can produce. In a low-resistance situation like when you're in ice, the engine can only put so much torque out to the driving wheels before they slip, which creates the upper limit of torque it can produce.
Stepping on the brakes in that situation increases the amount of resistance the engine works into, thus it can produce more torque which can be used by the tire that has more traction. Remember, the tire with the least amount of traction is the limiting factor so stepping on the brakes makes the engine think it has more traction (it feels the added resistance from your braking action) which can often provide enough additional torque to the side with better traction to get you moving again.
So step on the brakes fairly firmly as you give it gas at the same time, it's a balance thing that can only be learned by a little practice. When one tire is spinning, step on the brakes (or pull the parking brake lever up a few clicks if it's a rear tire) to eliminate the ineffective tire spin and give it some gas. If conditions are not too bad and you've done it right, odds are you'll start moving.
This age-old technique has been around since the Model-T days, too bad it's a lost art for most drivers today.
I tried doing this with my jeep when i was in some dirt with some spinning wheels but it was too easy to stall trying to negotiate all three peddles.
While the tires are spinning and you've got a decently high number of RPMs (I don't try it below 2000 or so) that's when you get on the brakes. You don't really need to be slipping the clutch since your tires are already slipping lol. It's really fun (and you know you're in it pretty good) when you can have it idling in first gear and you're not moving and the clutch is all the way out and it's not stalling.
2003 TJ X Silver | 31x10.50x15 BFG A/Ts | 10k front tow hooks, factory rear tow hook | 2" coil spacers | Cobra 19 with RatShack 102" stainless whip on an Arizona RockyRoad tire carrier mount | Kilby Steering Box Skid | AtoZ Fabrication Rock Sliders | Olympic Slider Rear Bumper w Receiver | Skid Row Engine/Oil/Tranny skid (still sitting in my living room)
Awesome write up, I will try it just for fun the next time I can. . . I'll have to do the manual method. I noticed it most when I used to brake torque my Ranger to burn the tires. I could see 2 even black marks when brake torquing, but only one black mark when I would just dump the clutch and burn out. I never understood why until now. Thanks for the technical info!!!
__________________ 'There is nothing more deceptive than an obvious fact.'Sherlock Holmes
HUMMM Nice Write UP. Some confusion I see on TORQUE & TRACTION, and not many guys have been stuck in the ditch with 2 wheal drive car.
The idea is to MAX Traction. Std Jeep will spin two tires and on min traction like ICE very easy to spin tires. The WRITER also refers to ICE as a LOW TORQUE TO ENGINE SITUATION. So is we increase TRACTION by spinning more tires by using rear axle limited slip avail as jeep option, installing rear or front locker we can ALL increase traction, THUS AS WRITER SAYS MORE TRACTION IS MORE TORQUE FORCE ON ENGINE. If We Have More Traction We Have More Force ON Engine, He is calling that engine force Torque.
Second if you find youself in the driveway stuck on ice patch or in the ditch with car or jeep with the A SINGLE REAR WHEEL SPINNING. STOP!!! You can apply THE EMERGENCY BRAKE about 1/3 force with wheels stopped. Try to accerate gently again and E BRAKE may stop the spining wheel with enough force the wheel with traction will turn with enough force to move your car. If not, go to 1/2 force on EMERGENCY BRAKE and see if that gets you out. THIS IS STRICTLY AN EMERGENCY GET UNSTUCK SOLUTION. YOUR REAR BRAKES CAN GET HOT AND IT IS A STRAIN ON JEEP / VEHICLE TO TURN & SPIN YOUR REAR WHEELS. This has no effect on your front wheels. This is for use with open axles for the most part, not limited slip axles. EMERGENCY USE!!!!
This is a great topic for newbies and old timers alike! Although I have only had my jeep for about 5 yrs, this was one of the first "tricks" I learned while on the trails. Having open diffs kind of made it a requirement to keep up with more modified rigs. With a manual tranny, as mention previously, knowing how to run three pedals with two feet is something that takes a lot of practice to do properly. The end result though is priceless... Having a buddy in a brand new rubi being astonished at what you can drive over, and it takes all he's got to get through with lockers!!!
Maybe I missed it, but was there a thread for "Driving Finesse"?? I am sure there are more of these items out there...
Will work for jeep accessories!
[COLOR="DarkGreen"][B]Colorado Jeep Club Member #221[/B][/COLOR]
[COLOR="Silver"]USN Jeep Hull #696[/COLOR]
If this is true then whats the point of a locker? Doesnt a locked diff distribute 50-50 tq every time? And stock diffs usually create a "one wheel wonder" effect from what ive seen at the drag strip. If both wheels were getting 50-50 tq that wouldnt happen would it. Thats why we weld the diffs on some drag cars.
An open differential always distributes all of the available torque to each side in a 50:50 split. The problem there is that there's not always much torque being sent to the tires in slick situations so even though each side does indeed always get a precise 50% split of the available torque, it's not always enough to keep you moving since the amount of torque being generated by the engine in low traction situations can be nearly zero. Read the above article for info on that.
Lockers however can distribute 100% of the available torque to just one side, the side on the ground with traction... or half to each side if each side has equal traction. But if one tire is in the air, the tire on the ground with good traction will receive 100% of the torque which will be much higher if the tire on the ground has good traction. With an open (non locked) axle, the spinning tire in the air will limit the amount of torque being generated by the engine to nearly zero.
With an open differential, the greatest amount of torque that can be generated by the engine will be that which is needed to turn the tire with the least resistance... i.e. like the tire in the air. So in that situation, the torque developed by the engine will be essentially zero so 50% of that nearly zero torque is what the tire sees on the ground... not enough to get you moving in that situation.
I assume tru-trac is the best LSD money can buy?
I assume this due to hearing:
-it needs no servicing/maintenance
-it is never felt during DD situations
-and if you high center a wheel (IE: one in the air and the other is not) you can simply power brake 9/10 times. By applying some minimal brake pedal while accelerating.)