hey everyone,

Today as I was using 4 wheel hi/low, I got a strange noise coming from the area around the break pedal. it was like a rattling noise when I pressed on the gas. when I stepped on the brake, it went away. I wasn't going fast at all, just barely even moving. I've also had the noise happen when I go over a hard bump. anyone have this happen to them?

 

Can you be more specific?

 

I'm not sure how to be. it sounds as if you were to take the brake pedal and make it go back and forth to cause a rattle. but it isn't in the brake pedal it sounds like it is coming from somewhere around the firewall under the dash.

 

DI or DII?
What gear was the t-case in?
Were you stopping, starting or driving?
How fast were you going?
Dry road, wet road, gravle road, or off road?

 

DII
high first, then low, then back to high
I was stopped and it happened as soon as I started rolling
1-2 mph
off road, in mud

 

Ok, that was your traction control. It uses the ABS to prevent wheels spin, so what you heard was the ABS module stopping the wheel(s) from spinning thus increasing traction, perfectly normal.

 

woah woah woah, I had no idea they could use the abs to sorta work in a reverse fashion. that is cool

 

Its pure physics, a spinning wheel is wasted energy, it has no traction so it does no good, so by applying the brake to the spinning wheel it stops spinning and then the power transfers through the axle to the wheel that is not spinning giving it more power to do the work of two wheels.
That is how they do traction control on all ABS equipped cars and trucks.
My wifes Volvo has TC, it works the same way, we can turn it off on the car though, so we can smoke the tires. Its fun.