auto 4wd system question

scotts03le · Apr 15th, 2004, 10:40 AM

sorry for the dumb question, but when the 4wd system is turned to auto (I have an 03 LE) how much power is going to the front wheels? when I switch mine over the lights go on, and there is a big difference in the feel of the engine and steering, they are much tighter. I normally use 2wd, but in the rain the other night I switched.

lofrontier · Apr 15th, 2004, 10:54 AM

Quote:

Originally Posted by scotts03le

sorry for the dumb question, but when the 4wd system is turned to auto (I have an 03 LE) how much power is going to the front wheels? when I switch mine over the lights go on, and there is a big difference in the feel of the engine and steering, they are much tighter. I normally use 2wd, but in the rain the other night I switched.

50% to the front and 50% to the rear. Only fancy pants cars like Subarus have transfer cases that alter power fore and aft.

Steering feels different because the front wheels are being driven now that you're in 4wd. Engine feels different because there is more of a load on it. It's all normal.

scotts03le · Apr 15th, 2004, 11:12 AM

I thought in Auto it is RWD until the front wheels slip? what is the main difference between auto and 4Hi other than the locking differential?

MrOldLude · Apr 15th, 2004, 12:48 PM

I'm not familiar with the "auto" option on your SUV, but I'd suspect the distribution is intended to be 50/50. On highend autos (think skyline and porsche 911) they have systems which automatically biasing torque front to back that transfers power when slip is detected. On Honda CRV's (not high end) power is given primarily to the fronts, and the rears receive power when slip is detected.

Subarus have viscous center diff's that allow for their full-time AWD. Since the connection isn't truly mechanical like a gear (there is a viscous fluid that transfers power, but not as much as a steel gear). When you have 4wd engaged and try to take a tight corner, you can feel the gears binding. That's the biggest difference between full-time 4wd and part-time 4wd.

lofrontier · Apr 15th, 2004, 01:04 PM

Oh! an '03 Pathy. Huh, I don't know how the transfer case works on it.

My friend has an Escape that has a fancy center diff that'll transfer power to the front wheels when the rears slip. Maybe your car has something similar

scotts03le · Apr 15th, 2004, 02:24 PM

not sure, that's why I thought I would ask. It felt like 4Hi instead of part time??