can Tire Size Mismatch cause front differentiial failure on a AWD 2004 MOUNTAINEER

[mexico41]

Subject says it all....the dealer wont repair under my extended warranty because of this....is this true?

 

[kert0307]

Yes, that is true. Different size tires can cause premature wear to the spider gears in the diff.

 

[mexico41]

So im screwed?.....they said it was different tread !!

 

[Turdle]

On an AWD vehicle the tires must be rotated and replaced in sets of 4. A smaller tire rotates faster.

even same size tires of different brands will have varied revolutions per mile. So a different tread will make the overall diameter different also.

Now you know. You should never, ever put 2 sizes of tire on the same axle, unless you drive directly to a tire shop to have it fixed.

This is further compounded by the awd system. It needs to see all tires spinning the same speed, or, it assumes there is traction loss and it will try to "kick in" the awd function. This will wear the differential and transfer case prematurely.

 

[matt0248]

I believe the numbers I heard a long time ago was all tires had to be within 3/32" tread depth. This was in a TSB I read s long time ago.

 

[mexico41]

is this mentioned in the manual?

 

[kert0307]

It is in mine, but it's a different set up than yours.

 

[SteveBarker]

I can't imagine a single scenario where it would be necessary to have different tread designs (meaning different brand or model of tire) on the same axle. This is a basic no no for ANY vehicle. And even worse on a 4x4

 

[mexico41]

thanks for all the replies......so with all that does it void my warranty because when i took it to the dealer they call me saying it is indeed covered under my ESP but....since it was 0ver $1500 they had to call a ford rep to examine the truck so fast forward to now he said the tires cause so they wont approve the fix is that possible i cant find anything on my ESP that would indicate that if did this or that it would not be covered...do i have i argument ?or am i ####ed because i dont have $2500 to fix.

Thanks

Vic

 

[jtrasap]

I have the exact same truck. What exactly is the front diff doing? If you have two mis-matched tires on the same axle it can prematurely where your diff gears. If they are mis-matched from front to back, you can burn up the viscous coupling in the transfer case and cause premature diff problems. If it's just whining, try replacing the front tires with two that match, have the diff fluid serviced, and remove the front drive shaft until you can afford to get a fully matched set of 4 tires. If you can afford 4 matched tires, you don't need to remove the front drive shaft.

There is a TSB that recomends no more than 1/2" difference in tire circumferance. If a tire has a smaller circumferance, it will case the truck to act as if a wheel has lost traction do to it having a different rotational speed.

 

[Turdle]

thanks for all the replies......so with all that does it void my warranty because when i took it to the dealer they call me saying it is indeed covered under my ESP but....since it was 0ver $1500 they had to call a ford rep to examine the truck so fast forward to now he said the tires cause so they wont approve the fix is that possible i cant find anything on my ESP that would indicate that if did this or that it would not be covered...do i have i argument ?or am i ####ed because i dont have $2500 to fix.

Thanks

Vic

Make them show you where it is stated that a mis match of tires will void your extended service coverage.

 

[Joe Dirt]

Tread shape shouldn't matter, it's the rolling circumference of the tire, so I'd question that...

It's kind of a difficult situation, not sure how your ESP was worded or if it included some language in there about the tires specifically. If it doesn't, and they were replaced like that at the dealer supporting the warranty you've got a case. If not, you're probably going to be screwed even if there isn't anything written about doing it specifically in the ESP paperwork.

They are going to refer to text like that on pg. 184 of the owners manual:

"If your vehicle is equipped with AWD, a spare tire of a different
size than the road tires should not be used. Such a tire could
make the vehicle difficult to control as well as result in damage to
driveline components."

or this on pg. 159

"Your vehicle is equipped with tires designed to provide for safe ride and
handling capability.

Make sure all tires and wheels on the vehicle are of the same size, type,
tread design and load-carrying capacity. If you have questions regarding
tire replacement, see an authorized Ford or Lincoln Mercury dealer.

If you nevertheless decide to equip your AWD for off-road use with tires
larger than what Ford Motor Company recommends, you should not use
these tires for highway driving. If you use any tire/wheel combination not
recommended by Ford Motor Company, it may adversely affect vehicle handling
and could cause steering, suspension, axle or transfer case failure as well as
the increased risk of loss of vehicle control.

Do not use “aftermarket lift kits” or other suspension modifications,
whether or not they are used with larger tires and wheels.

These “aftermarket lift kits” could adversely affect the vehicle’s handling
characteristics, which could lead to loss of vehicle control or rollover and
serious injury.

Tires can be damaged during off-road use. For your safety, tires that are
damaged should not be used for highway driving because they are more
likely to blow out or fail."

It absolves them of liability for modified vehicles, and will probably catch yours now too, unfortunately. I don't know if, as Turdle said, that is enough to void your ESP, but that all depends on how it is worded.

 

[kert0307]

Why not try putting identical tires on all the tires and go to a different Ford dealer to have the ESP?

 

[Dan Whitaker]

Why not try putting identical tires on all the tires and go to a different Ford dealer to have the ESP?

I'm willing to bet Ford has a documentation on it now so I doubt it would work.

 

[ericautopart]

Have they documented a denied claim due to different tread? If so, make some calls. That's no reason to deny a claim. If you find yourself totally screwed, give me a call. I'll get you out of that situation for much less than the dealer is asking.

 

[mexico41]

Thanks for all the replies.....well i called the warranty place and of course giving me the round around i ask for documentation that the miss matched tires indeed cause front diff failure and WHERE does it states on my ESP that if i did put on miss matched tires it would not be covered on my ESP!...HE SAID IT DOES BUT HE WOULDN'T TELL ME OR HE DIDN'T KNOW HOW TO TELL ME!!..SO when i mentioned that i would need proof of what i just stated to show my lawyer(which happens to be my little brother)dude clammed up since it was now a legal matter WTF!!...so the ##### gave me the # to their lawyer which of course is out of the office until Monday...and all this while my truck sits in John Lance Ford waiting to be fix...my poor truck.

 

[imp]

Mex, in my opinion, here is what I would do if this were my situation. If the truck is driveable (the front differential noise is not so bad as to sound like it's coming apart), make sure BOTH front tires are the SAME DIAMETER, then drive it home. If it is so bad, you do not want to drive it, or cannot, take off the front driveshaft, or pay someone there to do it for you, throw it in the back of the truck, make sure BOTH tires on the front are the SAME DIAMETER, and drive it home.

Then call Eric for a replacement front center section. You might be able to get a used one for a fair price.

Unless of course, you want to be involved in that lawyer-**** they are talking about. Just my 2 cents. imp

 

[Joe Dirt]

That's a good point, imp... You're most likely screwed through the ESP, so you're probably going to be throwing good money after bad trying to fight them. I would look to plan B on the most effective way to get your truck fixed so you can continue to drive it...

If you're sour on the warranty, heck- see if you can cancel it out, get a refund on the remainder, and use some of it to fix your Ex... Just thinking out loud...

 

[mexico41]

The truck is at the dealer as they would say on the shelf with the parts on side and as for cashing in the remainder of the ESP ...its ends on Halloween of this year.so prolly aint worth much.......ill prolly dip in the 401K and pay for the *****...but if they. Can't provide me proof why my warranty was no good even though the damaged to the truck is clearly covered under the warranty......why. Can't they just honor my warranty I paid 1800 For the ####in thing!!!!

 

[SteveBarker]

Subject says it all....the dealer wont repair under my extended warranty because of this....is this true?

Just get the tires matched up and take it to another dealer. This thread has gone on way too long.