4WD HI pulling left

So I threw it in 4x4 HI this morning on the way to work, going about 30-40MPH. I do this occasionally just so that it gets some use switching b/w 2WD and 4WD, and so that when push comes to shove and I really need it, it'll work.

The only other times I've had it in 4x4 were last winter in the snow, and on a camping trip crossing a stream in very loose gravel (this occasion I was going pretty slow).

Well this morning I noticed that it pulled left. I was going straight, but on pavement. I always make sure that I'm on a straight stretch of road when I engage 4x4 on cement. As soon as I clicked it out of 4x4, it tracked straight. I did notice that it only pulled left when I had my foot on the gas. If I let off the gas pedal, it tracked pretty straight from what I could tell.

Is this an alignment issue?

 

I do this from time to time too. I never do any turns or anything, just going straight, usually sitting in traffic on the highway.

Is this not a good move?

 

Mine tends to pull a little to the left as well when in 4x4. I thought it was normal.

 

No.... it shoudln't be. A bad allignment would cause you to track left ALL the time and not just in 4WD.

How far left does it track? Pretty badly or mildly?

Do you have to literally hold onto the wheel to keep it going straight?

 

I realize you "shouldn't" be in 4WD on pavement. I also realize that the issue that arrises from this is due to turning and the outter wheel needing to spin more than the inner wheel in a turn, thus binding the components of the 4WD drivetrain, which is why I make sure to drive perfectly straight when I do this.

Janster, I do have to hold onto the wheel to keep it in the lane. It's more like it'll drift left, I'd consider it somewhat quickly. It's not like it jerks left or anything.

Just curious if this is normal.

 

I'm really guessing here....but I'm wondering if you don't have any 'drive' to one of your front wheels. Hard to tell because I don't know how/where the 4wd actuator is on these trucks. Looks like the actuator is on the passenger side of the diff. Hard to say....and it's only a WILD guess.

Without even trying to offer any suggestions, since you have an 09...I'd just take it to the dealer and let them figure it out. If its that obvious...then you should be able to replicate the problem. It's definately not normal and should be looked at and under warrantee.

Good Luck and report back!

 

Are the front drive shafts equal lengths? I'm thinking it could be torque steer or some related driveline-wind-up effect.

 

All factory parts. I have billy 5100s up front @ 1.75, and an AAL in the rear, with aftermarket wheels, 265/70/17 tires. All the rest is factory, not sure how the drive shaft lengths would be different.

 

I have a prerunner, so I can't go look at front driveshafts. If the front differential is off to one side or the other, you end up with a short drive shaft on one side and a long one on the other. In FWD cars this leads to torque steer under hard acceleration.

 

So I think I figured out the issue, and I'll admit it probably would have been wise to explore this problem a bit further before posting for help.

Last night I checked the tire pressure, front left was a hair under 31, front right was 34. Temporarily I lowered both fronts to 30 and test drove. Issue seemed gone. I filled the fronts up to 34 and rears up to 32, tested again this morning, and it tracks straight.

I hadn't checked the tire pressure since I recently had the tires/wheels road force balanced. Apparently the shop didn't bother filling them equally.

 

Good to hear you got it figured out!