Bent axle

[TechWrench]

First thing I would try is to place a long straight edge across each of the rear wheels, horizontal with the ground. Comparing how each wheel aligns with the front wheels will tell you which side has a problem. Also, I would jack up the rear end at the pumpkin, and rotate each wheel to see if either one has a wobble when turning. If either side has a wobble, then your issue is either a bent wheel or hub. If neither side has a wobble, but one side has an alignment problem with the front wheel, that it is probably a bent axle tube on that side.

 

[Antoddio]

Oh it's an issue. Heavy tire wear on the outside of tire. Horrible sliding on slick or loose surfaces.

Ah. A lot of people complain about sliding on surfaces if they don't have full time awd. I can't imagine a bent axle would change that a whole lot, but I could be wrong. Tire wear doesn't lie if its happening quickly and all are inflated correctly, etc. So that's good to look at.

 

[jus10]

If neither side has a wobble, but one side has an alignment problem with the front wheel, that it is probably a bent axle tube on that side.

This. No wobble at all.

Ah. A lot of people complain about sliding on surfaces if they don't have full time awd. I can't imagine a bent axle would change that a whole lot, but I could be wrong. Tire wear doesn't lie if its happening quickly and all are inflated correctly, etc. So that's good to look at.

Driven in northern Utah since I was able to in every type of vehicle (sports cars to heavy haulers) with good and bad tires in all kinds of weather. This 4runner is the most uncomfortable thing I've ever driven in snow. I was getting passed by RWD cars on low pro's left and right because my rear end was pulling back and forth depending on which tire decided to have more traction (going in a straight line).

I rotated the tires around just to be sure and in less than 500 miles I can tell the uneven wear.

Dealer I bought it from more or less told me it's my problem. Fun times!

 

[ElZilcho]

I can't imagine a bent axle would change that a whole lot, but I could be wrong.

If the axle is bent causing toe-out it would cause the thrust angle of the truck to change every time the traction bias of the rear tires changed. i.e changing cross winds, road crown, steering input. OP mentioned 1.34* toe-out on one side. Drift cars and hill-climbers put about 0.5* toe-out to purposefully upset the balance of the rear of the car and make it easier to slide around.

 

[Antoddio]

This. No wobble at all.




Driven in northern Utah since I was able to in every type of vehicle (sports cars to heavy haulers) with good and bad tires in all kinds of weather. This 4runner is the most uncomfortable thing I've ever driven in snow. I was getting passed by RWD cars on low pro's left and right because my rear end was pulling back and forth depending on which tire decided to have more traction (going in a straight line).

I rotated the tires around just to be sure and in less than 500 miles I can tell the uneven wear.

Dealer I bought it from more or less told me it's my problem. Fun times!

We dang, we need a picture of this!

 

[Antoddio]

If the axle is bent causing toe-out it would cause the thrust angle of the truck to change every time the traction bias of the rear tires changed. i.e changing cross winds, road crown, steering input. OP mentioned 1.34* toe-out on one side. Drift cars and hill-climbers put about 0.5* toe-out to purposefully upset the balance of the rear of the car and make it easier to slide around.

Are we talking inches or degrees here? Mine has to be at least a couple degrees out on one side.

 

[ElZilcho]

Are we talking inches or degrees here? Mine has to be at least a couple degrees out on one side.

Degrees.

To be fair, adding toe-out is frowned upon in professional circles, but that doesn't mean people don't do it.

Two degrees of toe-out on any axle would be...terrifying to drive. Road tires generally break loose at ~3% slip ratio (depending on compound) and VSC intervenes around 2%. I'm making some generalizations here. I don't know Toyota's design specifications for traction control but that's the window most manufacturers use. If you were running 2* toe (in or out) I would imagine VSC would be interfering constantly or would fault out and throw a code/service light.

This is my experience with cars in general, not specifically this gen 4runner so take this all with a grain of salt. I'm happy to be corrected.

 

[TechWrench]

This. No wobble at all.




Driven in northern Utah since I was able to in every type of vehicle (sports cars to heavy haulers) with good and bad tires in all kinds of weather. This 4runner is the most uncomfortable thing I've ever driven in snow. I was getting passed by RWD cars on low pro's left and right because my rear end was pulling back and forth depending on which tire decided to have more traction (going in a straight line).

I rotated the tires around just to be sure and in less than 500 miles I can tell the uneven wear.

Dealer I bought it from more or less told me it's my problem. Fun times!

OK, so did you try the straight edge test, as I suggested? If so, what were the results.

If the tube is in fact bent, it needs to be fixed pretty quick. With the tube bent, it will change the angle of the axle bearing that supports the half axle shaft that goes to that wheel. This can, over time cause the bearing to fail, and could possibly cause the axle shaft to fail because of the constant flexing in the shaft. It may also result in damage to the differential assembly.

 

[jus10]

It's degrees as mentioned before but there's no "obvious" bend so pics won't do anything. I did measure it and there's approximately 1-1.5" discrepancy between the front of the rear tires and the back of the rear tires.

Everything ElZicho is saying is exactly what I'm experiencing.

 

[TechWrench]

It's degrees as mentioned before but there's no "obvious" bend so pics won't do anything. I did measure it and there's approximately 1-1.5" discrepancy between the front of the rear tires and the back of the rear tires.

Everything ElZicho is saying is exactly what I'm experiencing.

If you use the straight edge method, as I suggested, you should be able to isolate the problem to either the left or right side axle tube. One side should align with the front wheel, and the bad side should be the one that doesn't.

 

[jus10]

If you use the straight edge method, as I suggested, you should be able to isolate the problem to either the left or right side axle tube. One side should align with the front wheel, and the bad side should be the one that doesn't.

Thanks! I've tried but I can't isolate the bend as it sits. I'm pretty sure it's right at the end of the axle near the bearing and I know which side it is.

 

[TechWrench]

Thanks! I've tried but I can't isolate the bend as it sits. I'm pretty sure it's right at the end of the axle near the bearing and I know which side it is.

The straight edge method will not tell you where in the axle tube the bend is, only which side and if the bend is to the front or rear. So far, I don't recall you mentioning which side the problem is, only that the excessive toe is causing outer edge tire wear. So, I am assuming that the axle tube on the damaged side is bent forward, which should cause the front of the wheel to toe in, which would cause outer edge wear. If the toe was out, that would normally cause inside edge tire wear. The only other possible issue could be if the camber on that side is also bad, with the bottom of the wheel in further than the top, which also would cause the outer edge of the tire to wear faster. You could quickly check the camber angle by using a level held vertically against the wheel. But I assume that if you had the alignment checked by a competent shop, they would have already given you this information in the report.

 

[jus10]

Updated first post. Thanks everyone for their thoughts and help! Swapped the axle out with an identical used one and a weird thing happened, it drives straight while in the snow. Ha!

 

[ElZilcho]

Do you mind if I ask what you ended up paying for the used axle tube?