JoeOh

I just bought a 1995 Jeep Grand Cherokee Laredo, I6, 4.0L, Automatic Transmission. I had to have the oil change (both filters), transmission fluid topped off (still needs to be brought up a little bit). I checked the tranny fluid before topping it off, it was red, clean, and did not smelled burnt.

This Jeep has several different drive modes, 2x4 RWD, 4x4 part time, and 4x4 full time.

I tested the 4x4 modes today after having to put a full quart of tranny fluid in. (I bring the transmission fluid level up to the proper level soon.) But what I want to know is, when I tried to use the two 4x4 modes, it caused the steering wheel to turn by itself to the left and right several times as I gently pressed on the gas pedal. after I got up to 5mph the steering straightened back out and drove fine.

I put the Jeep back into 2x4 drive mode and it drove properly as it did before I tested the 4x4 modes.

What usually causes this, and am I in for an expensive repair? I hope I explained it well enough. If not let me know.

Bustedback

Was the wheel straight at the time it started acting weird, were you on pavement?

VTJeep

probably just torque steer? if accelerating in 4wd the front tires will grab and cause wheel to move accordingly.

VTJeep

also, the difference in the 4wd modes:
-part time: to be used when all 4 wheels can spin freely, i.e. on dirt on when in the mud/snow.
-full time: whenever you want. great for areas where pavement is partially covered by ice/snow.

the difference is that part time engages the front DS at all times. so when you corner, there is a tendancy for inside wheel to bind and hop. but full time only engages torque to the front DS if there is wheel spin. so under normal driving conditions and when making a tight turn in full time mode, the front DS isnt getting any torque.

JoeOh

I was on level pavement and the wheels were straight. What exactly is a "torque steer"?

This never happened when the Jeep was in 2x4 mode. Just the 4x4 modes for a few yards then it stopped and drove like it should.

Just wondering if it is a clue to a serious problem is all.

VTJeep

usually associated with a fwd, torque steer is when the tires grab at uneven parts of road causing the steering wheel to pull back and forth a bit. the harder you accelerate, the more aggressive the torque steer.

edit, it wouldnt happen in 2x4 cause its just the rear tires applying the acceleration. the torque steer in a fwd issue.

721

I wouldn't be to worried about it.

Bustedback

1st, don't use 4wd on dry pavement, it will cause exactly what you're feeling. 2nd, you'll have torque steer because the front axle shafts are different lengths, the right shaft is longer and twists like a torsion bar where the left shaft is shorter and will not twist at the same rate as the right side, more power is making it to the ground on the left side and pulling more.

721

To clarify, never use 4Lo or 4 Part time on dry pavement, 4 Full time is fine on any surface.