I think so… i just dropped my truck (02 Explorer XLT 4.6) off at West Herr for an issue which i thought was with the transmission. under hard acceleration under load (like going up a thruway on ramp), the truck would buck and jerk in the driveline. I thought it was the transmission slipping because i know these things are known for bad transmissions.
So, the “shop foreman” at West Herr went for a test drive with me. he drove it, felt the problem and said “its the transfer case, which is slipping and caused by your tires.” I recently just put new tires on the truck, which are Interco TruXs MTs. They are a LITTLE bigger than the stock size, but not by much at all.
The “shop foreman” proceeded to lecture me on how these trucks are very very sensitive to tire circumference blah blah blah and that if the circumference is off by even 1/2" then it will effect the the transfer case and if you blow out one tire you have to always buy 4 new tires otherwise it will be thrown off again blah blah blah. So he gets it to replicate the problem with me in the truck on a test drive, and in the middle of it doing it, he puts it in 4 wheel and it stops.
now, my question is, if the tires were causing the AWD to be messed up like this, wouldnt it do this ALL OF THE TIME and not just under hard acceleration under heavy load? I know the AWD system in these things works by sensing if the rear tires slip more than 1/4 turn, then it locks the front diff in. I posted on the Explorer forums, and the general consensus about this system seems to be that as long as the axles are turning at the same rate, there should not be a problem at all. I also had this problem a few days before i got new tires (no way they believe that thought because it wasnt documented).
I have the feeling they are going to end up diagnosing this based on what will cost them the least amount of money. My warranty is almost up, and they know this, and probably figure as long as they can get me through the end of the warranty they dont have to deal with it after that. Opinions? suggestions on what to do or what to tell them?
With most AWD cars and trucks you want to replace all the tires at the same time because of the rolling diameter is different therefore causing binding in the t-case, at least thats what I have been told. how much of a size differance is in the new tires complaired to the old.
all 4 tires are 100% identical. I read on the Explorer Forums that having different sizes on the front and the rear will cause this problem, as the the “system” will notice that the front axles are turning at a different rate than the back ones, and use the AWD system to compensate/correct that. That makes perfect sense to me, but all of my tires are the same size.
I believe the old ones were 245/65/16 and the new ones are 235/84/16. the way the dealer was talking, they said if you have 4 tires that are half worn, and you need to replace one (due to a blowout or whatever) then you need to replace all of them because that minor difference in the the tread of the new tire to the other half worn other 3 is enough to fuck up the system. Im sorry, but that sounds so rediculous to me, and i have a hard time buying it.
Exactly, as long as all the tires are the same and replaced at the same time it doesn’t matter if they are larger or smaller.
And tires WEAR more than 1/2" in circumference during their lifetime; it’s all about keeping them even.
The dealer is actually correct, if you have 3 tires that have 1/2 their life gone, you need to match the 4th tire. They all need to be the same in a 4wd system, or it causes nightmares.
but as long as all 4 of my tires are the same size, it shouldnt matter how big or small they are compared to the old ones, just as long as all of them are the same size, correct?
Dealers love to get away with cheap fixes. Hence why I called gm direct numerous times about my Silverado when paddock would not fix it. I have not yet called Toyota, northtown seems to be good about fixing stuff, and when a tsb comes out they replace the parts without question. they have been dicking my g/f around about her new r32 though, the ipod interface has not worked yet and its been a month, so tomorrow we are going there wanting a rental and for them to take the car until its fixed! We will keep track of the miles also. My friend took his mustang gt to “a dealer” for warrantee work, got it back filthy and 67 more miles.
Tell them you think its something more and you also think there just trying to put the real problem off till its out of warentee, so they better look into it more then just a test drive or your calling ford direct.
I would advise you to determine EXACT circumfrence measurements. Easily done with a piece of rope wrapped around the exact center of the tire, then measuring it after you’ve wrapped it around. Make sure it’s not elastic at all. If you find them within 1/2" rolling diameter, then press further.
And actually, I’d have the shop do it with you there.
yeah the only thing that sucks is going in there and being like “well these people on these forums said you’re wrong” will never work haha if only it was that easy.
i dont know if this is in any way related or will help, but blazers had a problem with there trans. slippin/ not going into 4x4… and when the case was slippin, the fix was a 3 nipple vaccum “box” that screwed on to the top of the trans, and fixed the problem…
#1: If all 4 tires are same diameter it’s not an issue, as has already been said.
#2: If you just want to fix the issue and stop wasting your time with the dealer, change the fluid on the transfer case. Those auto 4wd transfer cases are very particular about having fresh fluid. I have to change the one on the Expedition every 20k or so or it starts clunking on accelleration. Change the fluid and it’s as smooth as can be for another 20k.
It’s like $10 in fluid and 30 minutes of your time. I don’t know what your time is worth but mine is worth enough that I don’t like wasting it fighting with some asshole stealership.
