$h*t! Did I damage my Ex with a donut tire?

[RedBowTies88]

I experienced an unfortunate flat the other day while out in the woods doing some target practice with friends.

The tire was unrepairable, and I never got a spare with my explorer. One of my friends was gracious enough to loan me his donut spare and since I mounted it on the front, and have the control-trac disabled I didn't think it would cause any damage.

After driving about 15 miles at low speeds (under 40) I started hearing a god awful clanking sound that sounded almost like a shock mount had broken off or a ball joint had really badly worn and was slapping in and out of its seating.

I stopped and jacked up the truck, and the hub is tight as is the shock is firmly attached and so are the ball joints. When I rotate the tire is when I get the loud clank.

So how screwed am I?

 

[koda2000]

By having one small wheel/tire what you may have damaged is the transfer case. 4x4's and AWD's must have 4 tires the same size.

 

[RedBowTies88]

Even though it was not engaged?

 

[koda2000]

Even though it was not engaged?

I believe with Control Trac it's always ready to be engaged if it scenes wheel slippage. Having a small tire can be interpreted as wheel slippage. I could be wrong, but I'm pretty sure that's how it works.

 

[RedBowTies88]

I believe with Control Trac it's always ready to be engaged if it scenes wheel slippage. Having a small tire can be interpreted as wheel slippage. I could be wrong, but I'm pretty sure that's how it works.

Normally I would agree, but the control trac is disabled on my explorer.

 

[Robman]

Well, information as to where the noise is coming from would be good to know.

 

[drdoom]

Do you have any contact of the donut rim to caliper, knuckle, or ball joints?

 

[drdoom]

And when you say you jacked the truck up, do you mean just the one wheel?

 

[drdoom]

Any updates?

 

[SoNic67]

The manual says "use equal tires at all times", it doesn't say "only if Control Trac activated".

The front differential is always engaged to the front wheels, even if the Transfer case is disconnected. Driving with two different size tires forces the differential to run asymmetrical. Also, the geometry on suspension for that side is way off, forcing the half-shaft to run with an extreme angle.

My bet is that the half-shaft on that side is blown.

 

[C420sailor]

Throw the proper size wheel/tire on and do tight slow speed circles in a parking lot or such. If it's a popping that gets worse when you do that, it may be a CV axle.

 

[manimal]

Running one size asymmetric on the front can cause the suspension to stay flexed in odd ways as long as the small tire is in play. I would guess the others are right about CV shafts, as you could have caused the CV to run at a severe angle continuously.

If it were me I would consider it an advantage since that CV was likely on its way out to begin with, you just never noticed during normal operation and suspension geometry.

Nevertheless you should really pull the donut and check to see what's making the noise, versus guessing.