Truck Pulls to the Side

[LARIAT 85]

I started driving Lucille a bit more lately, and I have noticed that she pulls to the LEFT quite noticeably whenever I let go of the steering wheel.  If I hold the steering wheel completely straight, it pulls to the LEFT quite quickly.  I took it to my local tire shop and had the alignment checked, and it was dead on.  The mechanic thought it may have been a tire issue, so he swapped the two front tires around.  But the issue remains.  

Does anyone have any ideas?

[Pete Whitstone]

Might be a brake dragging on the left side? Or some other kind of resistance like a bad bearing? If you jack up both front sides, are the tires about equal in the amount of force it takes to rotate them?

[1986F150Six]

I was thinking the same thing. Years ago, I had a vehicle which would do the same and even sometimes pull the opposite direction when the brake was released. One of the front flexible brake hoses had broken down inside. The hose would baloon when pressure was applied and then collapse when pressure was released.

[Rembrant]

Hey Rick,

Did the shop to a 2 wheel alignment, or four? I think I'd also check the back end to make sure nothing is loose or out of line somehow.

To rule out anything in the steering box, you could maybe pop the power steering belt off and take it for a drive?

[mat in tn]

the accuracy of the alignment is a real point. not all know how to properly set up twin I beams. I have had trucks come to me having just been quoted dead on and I could see them being off with the naked eye. in fact, I stopped using shops twenty years ago for alignments because I do modifications and I got grief, so I do them myself.

[LARIAT 85]

I don't think anything is dragging.  My idle speed is set to 500 RPM in gear, and my truck still rolls away whenever I take my foot off the brake.

Thanks guys.  

Could it be my steering gear box?  Would that match my symptoms?

[BigBrother-84]

Ok, I'll say something probably completely stupid... But, does Lucille pulls to the left on ANY road?
I had Big Brother pulling to the right on some streets here, and found that it goes straight on the highway and some other roads.
Some streets have slopes or are domed enough to make the truck pulls one side, even in a straight part.
It saved me an alignment job.