How bad is 1.5 degree too little caster on my truck?

Specs call for 4.5 degrees positive caster on my 04 Ram 1500 truck. I have 3.0 and 3.3.

There is no adjustment on my truck for caster, so I will need to install an aftermarket kit if I decide to correct this 1.5 degree error.

How much of an issue will this cause me?

275/60r20 in case that makes a difference.

 

caster doesnt cause tire wear. its what makes the front tires want to steer streight. if your steering feels light and doesnt seem like it wants to return back to center as easy as you want then correct with off set ball joints. if it feels fine to you then leave it alone.

 

I don't see it causing you any problems. Won't cause tire wear or pull as long as both are as close as they are. If there was a big difference from left to right it would likely pull but not likely cause tire wear. The specs usually give a range the caster can be within. I'm betting they are very close to one end of that range. Nothing has happened to the truck to drive the wheels backwards, has it? I doubt it or you would have been having some pretty serious problems before now.

 

It is pretty far out of specs, but pretty even.

I have driven over a couple of curbs to get onto parking spaces in the grass, and other than that, hit a couple curbs at very low speeds while parking. Will that throw it off this much?

Here is a pic of the AFTER diagram after the allignment. The caster is pretty far off the acceptable range...

 

So between 4.0-5.0 is spec. Rt side is out .07 degrees and left is out 1.0 degree in order to be within specs. If it feels good to you in turns I would just forget it. If it feels funny then get the kit put in. If it was mine I'd drive it as is and maybe get it checked again in a year or so.

 

It's good that both caster degrees are positive and fairly even. Having a caster difference between sides will cause one wheel to pull.

In my stock car building days, I set the left spindle at 1 degree positive and then the right side at 4 or 5 degrees positive. The car will always pull towards the direction of the least amount of positive caster.