Questions on Steering and Alignment

[btanchors]

I have a 2006 Tundra DC 4WD that I bought new back in January.

Around 8,000 miles, I began noticing the passenger side front tire wearing on the outer edge to a significantly greater degree than the other three tires. In fact, the other three tires appeared to be wearing perfectly evenly. This appeared to me as being an obvious problem with alignment.

At the time, I was also experiencing another problem, but one that I did not attribute at that time to alignment. During turns, it "felt" like the truck was in 4WD mode on dry pavement. In other words, it felt like there was a scrubbing sensation on the tires. About the same time I started noticing this sensation, I had also changed all the drive train fluids to synthetic, and since I have a Limited Slip Differential, I thought that I might be experiencing clutch chatter, especially since I had not added the special additive used on LSDs.

Well, I finally decided today at just over 11,000 miles to take the truck into National Tire and Battery (NTB), a local chain that sells tires and does other work such as alignments. I took it to them because they always give you the complete alignment data, both before and after the alignment.

The guy told me the alignment was "way out". He said they don't align these trucks at the factory, and it was rather common for them to be out of alignment when new. Now that I have the truck back after the alignment, I no longer have the "scrubbing" sensation when steering. It appears the alignment fixed that problem. Only time will tell if it fixed the uneven wear problem as well. I had them rotate the tires - Front to back and back to front.

My questions are:

1) I figured that they don't align these at the factory, at least, not in the sense alignment is performed when you take your car in for alignment. But I did assume they must have some method of assuring a newly manufactured car/truck is pretty close to proper alignment when it comes off the assembly line. This is the first time I have ever had a new vehicle significantly out of alignment when new. However, this is also the first pickup truck (and 4WD vehicle) I have purchased as well. Is it really common for them to come from the factory out of alignment? I don't recall ever running over any curbs or potholes since the truck was new.

2) When I have had cars out of alignment in the past, I have never noticed the sensations during steering I felt when the truck was out of alignment. Is the steering on the Tundra such that being out of alignment could cause this sensation, or was I "grossly" out of alignment? Could it be that 4WD trucks are more sensitive to this issue, or could it be the fact that the tires on this truck (17 inch, 265/275, can't remember which) tend to have this issue when out of alignment?

Anyway, what I am trying to say is that the only symptoms I have ever observed on vehicles that are out of alignment are pulling to one side, or uneven wear. I've never had a vehicle "bind" or "scrub" when the tires are out of alignment.

[DJ]

Excellent questions, and a fabulous post!

Vehicles come off U.S. assembly lines at about one per minute. Toe alignment MUST be adjusted properly on each vehicle to make the steering wheel level when the vehicle rolls in a straight line, and to prevent tire wear, since incorrect total toe can wear tires out VERY quickly. The factories generally have five "production toe set" machines, which are VERY expensive alignment machines they use only for setting toe. Usually, one is down for maintenance and calibration while four are in operation, thus allowing four minutes per vehicle to adjust toe. It works well.

However, these machines are most definitely not suitable for adjusting camber and caster on a Tundra. Instead of doing so, I think Toyota simply sets the cams for adjusting camber and caster to "nominal" positions and relies on the wide tolerances "allowed" (+/- 0.75 degrees) to accept the resulting camber and caster values as "OK". The result is that each vehicle comes off the assembly line with its camber and caster alignment somewhere "in spec", but not necessarily close to what is required for proper handling and/or long tire life.

So, yes, they usually come from the factory with poor alignment.

Ideally, when the wheels are steered to one side, you could extend the axles of all four wheels (figuratively speaking, of course) and they would meet at a common point. The vehicle would steer about that point.

But the steering system of the Tundra is far from "ideal". Even when it is perfectly aligned, the two front wheels do not steer about a common point. The result is that one or the other, or both, of the front tires have to scrub sideways a bit when you turn a corner, any corner, at any speed. This is the cause of the black rubber tire prints that you leave on clean concrete when you make a turn, even a slow turn.

A poor alignment accentuates this. If it's bad enough, you can see it, feel it, and hear it. That's why you no longer feel a "scrubbing sensation" after the alignment.

Ya done good, and it seems you've found a good alignment guy.

[tempetom]

I always wondered about the tire prints when I back and turn out of my daughter's clean driveway. Now I know. I'm really reluctant to get my ball joint recall work done because right now, I feel my truck is aligned perfectly (just the way it drives and tire wear is good).

[btanchors]

Well, I spoke too soon. I'm still getting a scrubbing/vibration/shudder/rumble sound that seems to be coming from the front of the vehicle. Because I am no longer sure this is a steering and suspension issue, I have posted a new topic in the engine and drivetrain forum:

Strange Vibration Problem

Folks, have a look - Could use some help trying to identify this issue, for those of you interested in this sort of thing....

[81toypu]

Changing to synthetics is a great idea. But why in the world did you not put the additive in when you changed the gear oil? If the Synthetic you used does not state that it does not require it then you must add the required Limited slip additive in order for the clutch packs to opperate properly.

Change the oil again! But use the additive!

[btanchors]

Thanks for your response...A couple of points:

The back of the bottle of Amsoil Severe Gear 75W-90 states, "Compatible with conventional and synthetic gear lubes and most limited slip differentials. If limited slip chatter occurs, add AMSOIL Slip-Lock additive."

I do not think what I am experiencing is Limited-slip chatter...For the following reasons:

a) I drove the vehicle around in figure-8's at 5 and 10 mph. I could not get the problem to occur.

b) Others with the same model of truck and Limited Slip Differential are using this same oil without chatter, and without the additive.

c) The sound/vibration sounds like it is coming from the front of the vehicle, not the rear, although I am not 100% certain.

In spite of this, assuming the problem IS LSD chatter, is this how that problem would normally manifest itself? If I go ahead and add the LSD additive, and that turns out NOT to be the problem, will the fact that I used the LSD additive cause any problems, even if it was unneeded?

Thanks for the help!

[81toypu]

Well i was guessing you meant you had a LSD in your front diff. But, no adding the additive should not affect any thing if you have just an open differential. However, if the clutch plates dont slip and just grab it could cause a problem, especially if one side is grabbing more than the other. Its really hard for me to tell you for sure what the problem is with out driving the vehicle myself in this case. kinda an unusuall sitituation.

Does it make any popping, or clunking noise when you turn one way or the other? Another possibility is a defective CV Joint.

[btanchors]

There is no popping or clunking noise when turning, or at any other time. This is the only problem I am experiencing. Does LSD clutch chatter generally happen only when moving, or can it occur when accelerating from a stop? In other words, how do I recognize if I am indeed experiencing LSD clutch chatter?

I do not think the Tundra 4WD front differential is limited slip - I think only the rear is....Anyone else know for sure?