Traction Control Problems related to tire size?

[SDVike]

Now that I am debt free I was thinking about getting a spare that matched my 265/75R16s. I was going to get a used one at that size, and throw it on the spare rim that came with the truck, but the tire salesman told me unless it was almost exactly the same size as the tires on the truck it would wear out my 4 wheel drive. It has something to do with the traction control kicking on and off. He wanted me to buy a fifth tire and rotate it with the other four. His explanation made sense, but it also sound like he just wanted to sell me another tire.

Should I buy 1 more new tire now that I have 10,000 miles on the old ones, or can I get away with a worn spare.

 

[SDVike]

Also, If there is a problem with tire size affecting the traction control, would the brown wire mod fix that if the spare has to be used.

 

[RoadBully]

I may be completely wrong... but I really think he's just trying to sell you another new tire.
I mean we're talking about a spare here... so if you EVER use it, it will be just to limp you home till you get your good one replaced right?
If you had matching rims, you'd probably rotate in your spare, and then yes.. I can see buying everything to match.
different size tires will hurt your 4wd system, but as far as a worn 265 compared to a new one... I really doubt it'll do too much damage before you can get the good one replaced.

Just my .02


Ben.

 

[SDVike]

Thats kind of what I was thinking. My only concern is I plan on doing a 70 mile trail latter this year in a remote area of Colorado. If I should blow a tire 30 miles in, all I would have is that spare, until I could get back to civilization.

I just might get a new spare if the wear isn't to bad. That would give me an excuse to by new rims. Do you feel like building 2 tire racks?

 

[RoadBully]

That's a possibility,
I should have mine done in the next couple weeks.
I'll post some pictures up when it's done.

 

[Mbrooks420]

You should be fine. I've had my front tires wear and go much balder than the rears, and my t case is as fine as should be expected.

 

[SDVike]

I don't think it both tires are bald it affects the sensors, just one. I also would be really suprised if 10,000 miles worth of wear would affect it.

 

[RoadBully]

yeah, I'd say you'd be fine... that's nowhere near even being a full tire size smaller.

 

[JCUZ]

Maximum tread when new on these tyres is around 8mm (1/3"). Minimum legal depth is 1.5mm, therefore the maximum difference between old and a brand new spare would be 13mm, or 1/2" - I wouldn't think that's enough to affect the traction control and 4WD system. And if you had a spare that was around 50% tread (say 3 to 4mm, or 1/6" remaining), then you're talking at most, 1/4" difference or thereabouts. Again, not enough to worry about. Once you get into a whole inch or more difference, then it may cause issues, but even then, really only if you had LSD at each end (which I don't think the explorers do anyway).

 

[Carguy3J]

Mbrooks420:
You should be fine. I've had my front tires wear and go much balder than the rears, and my t case is as fine as should be expected.

You're playing with fire, and sooner or later, assuming you keep the vehicle and don't pass your problems on to someone else, you will get "burned"

Maximum tread when new on these tyres is around 8mm (1/3"). Minimum legal depth is 1.5mm, therefore the maximum difference between old and a brand new spare would be 13mm, or 1/2" - I wouldn't think that's enough to affect the traction control and 4WD system. And if you had a spare that was around 50% tread (say 3 to 4mm, or 1/6" remaining), then you're talking at most, 1/4" difference or thereabouts. Again, not enough to worry about. Once you get into a whole inch or more difference, then it may cause issues, but even then, really only if you had LSD at each end (which I don't think the explorers do anyway).

Not true. Modern T-case/drivetrains are VERY sensitive to even small differences in tire circumference. See the following articles:

http://www.rsgear.com/articles/2006_10.pdf

http://www.atransmissioncity.com/?menu=nuggets

http://www.rsgear.com/articles/2007_12.pdf - particularly read Step 1, which begins on the lower right of page 1 and continues on top left of page 2. It address the critical nature of tire uniformity.

This is also a good article to read: http://www.transmissiondigest.com/tech/TD200606/UpToStandards/Up To Stds HTML.htm
While it doesn't specifically address the tire size issue, it makes, and illustrates, a good point about the need understand and account for how many, seemingly unrelated, vehicle systems work together and can affect one another. Rather then just "guessing" or "throwing parts" at something, one must step back and carefully evaluate the true cause of a failure.

EDIT: I just saw, after posting, that this thread has been "dead" for 4 years! So much for not "jumping the gun"

Oh well. It is still a valid point, and something that has been discussed, with much misinformation. So, I'll leave this post. Hopefully the links will still be useful to someone!

 

[waskly]

when you buy tires you buy 4, if you change mfg you buy 5.

 

[Styx]

If you get a spare that is close to the same tread depth as the ones on your truck and it's the same size, type, and manufacturer, you will be fine..
Also the brown wire mod would totally resolve the problem....

 

[Mbrooks420]

You're playing with fire, and sooner or later, assuming you keep the vehicle and don't pass your problems on to someone else, you will get "burned"

When this was posted my truck probably had 120k, maybe a little more. I've recently rolled over the 200k mark with no driveline issues except for the common v8 front drive shaft failure. I never rotate my tires like I should, and the fronts and rears always have a noticeable tread difference by the time I get new tires. I don't think the viscous coupling setup is all that sensitive. My truck is amazingly stock considering the tons of plowing, the way I drive, and the general lack of maintenance.

 

[fusseli]

http://www.rsgear.com/articles/2006_10.pdf[/url]

http://www.atransmissioncity.com/?menu=nuggets

http://www.rsgear.com/articles/2007_12.pdf - particularly read Step 1, which begins on the lower right of page 1 and continues on top left of page 2. It address the critical nature of tire uniformity.

This is also a good article to read: http://www.transmissiondigest.com/tech/TD200606/UpToStandards/Up To Stds HTML.htm
While it doesn't specifically address the tire size issue, it makes, and illustrates, a good point about the need understand and account for how many, seemingly unrelated, vehicle systems work together and can affect one another. Rather then just "guessing" or "throwing parts" at something, one must step back and carefully evaluate the true cause of a failure.

EDIT: I just saw, after posting, that this thread has been "dead" for 4 years! So much for not "jumping the gun"

Oh well. It is still a valid point, and something that has been discussed, with much misinformation. So, I'll leave this post. Hopefully the links will still be useful to someone!

Yup, I believe that Ford says in the owner's manual somewhere that for both A4WD and AWD the difference in tire tread should NOT exceed 2/32" (1.6mm).

I have used my spare tire once, so when I switched to oversized tires I bought a mostly worn out spare of the same size for $40 from the tire shop. It doesn't make sense to have a new spare unless you do a five tire rotation, but you definitely want a spare of at least the same tire size.

Either way I don't think it'd be wise to go a a several hundred mile trip on a spare, anyways

 

[NICKYMUM]

Look at it this way.......

Thats kind of what I was thinking. My only concern is I plan on doing a 70 mile trail latter this year in a remote area of Colorado. If I should blow a tire 30 miles in, all I would have is that spare, until I could get back to civilization.

I just might get a new spare if the wear isn't to bad. That would give me an excuse to by new rims. Do you feel like building 2 tire racks?

........what if you blew TWO tires ...... would it matter then?????

 

[Bandit23]

holy old thread batman...

 

[projectnitemare]

Old thread or not, I can tell you putting a different size tire on that doesn't match the other 3 in size will screw with the traction control. I had to do it once when I had a valve stem snap off a TMPS, the spare was smaller. You will get the traction control coming on because there is a distinct difference in wheel speed. Also fyi...if you have a limited slip you need to put a smaller spare on the front, you will toast the limited slip.