Steering Wander with Terra Grapplers

[jno]

I purchased a set of 285-75-16 Terra Grapplers from Discount Tire. All seemed well until I drove onto the highway. At 65mph it is all I can do to keep it in one lane. ( like 2-3" of steering play) I don't believe there are any mechanical issues since I replaced ball joints, shocks, and sway bar end links months ago. Also, I did not have any steering wander with my old worn out Cooper tires.
Does anyone know what the tire pressure is supposed to be with these tires?

They put 60 in the front and 65 in the back, could that be the problem?

Any Ideas?

Oh yeah, it is a 2004 crew cab with diesel.

Thanks in advance for any suggestions.

[skid326]

I have the same problem...I probably have 1-2" of steering play. I got mine put on and left straight from the shop for a 250 mile round trip to the beach. I thought I was going crazy and that something was seriously wrong. It felt like my rear end was floating all over the road

[jno]

That is funny. I had the new tires put on on Friday morning because we planned on driving to the beach and a concert that night. (about 200 miles) We figured it was safer to take the truck since we would not be getting back until late. (highway after midnight)
I figured I would have the wife drive up and I would drive back. We get on the highway and she is all over the road. Of course I said "pull over, let me drive". Well, she was correct, the thing would not stay in one lane. (never live that down)
Since we were already late I figured I would keep going. I will tell you that was one of the scariest white nuckle drives I have ever taken.

- what I looked like driving home (without the smiling)

The next day my BIL who is a mechanic came over and said both of my tie-rod ends were loose. I changed those (Moog-$250) and it has helped a little. It is going in for an alignment this weekend. I have messed around with the pressure a little and got it where it is at least driveable. (55 front-70 back)

I am wondering if my steering box is junk? Why would it be okay until I put the new tires on? I have read where it can be tightened, but I will wait until after the alignment to try that.

I do know one thing, I will NEVER buy the Terra Grapplers again.

[skid326]

My sister's mom has 33 inch terra grapplers on her 7.3 and it doesn't wander at all. I have a buddy that has them on his '06 duramax, same size as mine, and they don't wander at all so I think it might be something with the pressure or the trucks

[LHMissions]

ive had 2 sets of 305/70R16 Nitto Terra Grapplers and now a set of 295/70R18 Terras and havent felt any sterring wander?

[jno]

LH, what are you running for tire pressure?

[Davey~do]

Originally Posted by LHMissions

ive had 2 sets of 305/70R16 Nitto Terra Grapplers and now a set of 295/70R18 Terras and havent felt any sterring wander?

ditto. I'm on my second set of Terra Grapplers on my truck, my wife's truck still has a set on them, plus I had a set on my Jeep TJ back in the day and never had an steering issues other than worn steering components.

[jno]

Davey, what tire pressures are you running?

[EODguyJake]

I have Terra Grapplers (almost worn out) and I've never noticed the truck wandering. I always run more TP up front than out back, and I think you are running them too high. I don't know what your truck weighs, but I come in at 8350lbs which is kinda on the heavy side for an extended cab, short bed, SRW. I run 58 up front and 54 out back. Plus, I have about a 250-300lb grille guard hanging on the front end, and I'm still running lower PSI. So IMO your pressures are too high.

[Dasaliac03]

balljoints maybe

little rim, big tire = dont handle well