Issues with bigger tires and transfer case

Ok, i just dropped my truck (02 XLT 4.6) off at the dealer 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 the Ford dealer went for a test drive with me. he drive 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, they are 235/85/16

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? thanks in advance for the help. I've been fighting with this dealer for a while tog et a bunch of issues resolved. Don't get me wrong, I love my Explorer, but with all of the problems I have had with it thus far, I want to get rid of it.

Your mechanic doesn't know what he's talking about.
If putting bigger tires on an AWD system hurts the transfer case, guess what....towing would be even worse!!(but it's not)

The only ways you can hurt the transfercase/tranny are....

1.)Driving style
2.)Excessive water
3.)Neglect, not checking fluid levels
4.)Using improper tire size combinations
5.)Lack of proper installment/ alignment


I just got a set of BFGoodrich M/T's on my Mountaineer, v8 AWD.
I went from 235/70/16, to 245/75/16.
They are quite a bit larger, fit in there nice.

I noticed it takes alittle more gas to get her moving, braking isnt quite as good.(never was anyways). And my steering was pretty much the same.
Also, the tires howl, and I get alittle vibration...which is normal.
The tires arent even worn in yet.


Ford made the AWD to withstand alot of load. Whether its tires or towing.
As long as you're tires arent low on air or mis-matched.

Also make sure to check your transfercase and tranny fluid.

Also try to take it easy with the truck, since it does have bigger tires.
According to the manual, O/D should be kept off during hard acceleration/towing/up hill climbs.

So next time you merge in traffic, just turn O/D off, then once you get to highway speed, turn it back ON.
Sometimes O/D is just a fifth gear, but according to the manual in front of me, O/D is more than that.


Also certain years of explorers are KNOWN for having transmission problems.
It's possible your truck is a lemon, or you drive it too hard.

I doubt the problem is your transfer case, since I believe AWD only kicks on ONCE you lose traction....I dont think it turns on during hard acceleration.
The problem is probably your transmission....although the transfer case is usually built into the transmission.


The manual says NOT to use over-size tires.
But heres the catch, it says to not use over-size tires ON THE ROAD.
Not because of the AWD system, but because Ford could be open to lawsuit on highways and government/state roads.....but NOT off-road.
(if you got a blowout or flipped your SUV off-road, Ford WOULD NOT be responsible and courts would rule automatically that it was Driver Neglect, or Reckless Driving.)

So this proves ONE THING.
AWD with oversize tires IS fine on the roads.
Ford only says not to use Large Tires on highways because of legal issues.
They tell you that you can do it Off-road though!!
(weird last time I checked....using AWD alot off-road is HARDER on the transfercase than using them on-road!!!)

Basically Ford is just sayin all that crap because if you get big 'ol mud boggers on your exploder, and then drive on the highway everyday and never check your air pressure....suddenly you got transfercase problems, now your blaming Ford. When it was really your own fault for not keeping up with maintanence.



Theres plenty of people on the forums here that use Mud Terrains on AWD v8 Mountaineers and Explorers.
Your problem is most likely just a coincedence, or a rare case.
Theres been people on here with AWD and using mis-matched tires for 30-40k and FINALLY start having minor transfercase problems. lol.

Besides your truck shouldnt jump or buck because of transfercase....that would be tha transmission! Or Clutch.

The power output is 65% Rear, and 35% Front anyways(AWD). That transfercase wouldnt have enough power to cause the truck to stumble or kick.
It'd either click on, snap a gear, or do nothing.

thanks for the info! i got it back from the dealer, and they swore up and down that was the problem, so i pulled the 4x4 fuse at the advice of them, and guess what? it still does it!

Same Boat

Sounds like the problems I was having with my 03 4.0L 4x4.

Under hard acceleration I'd have a loss of power and the engine would just rev, or on the highway trying to pass the thing would jerk and buck. I was afraid this may have been caused by my tires, 265/70/16, and I didn't want the dealer to void my warranty, so I stuck a set of stock tires on it before I took it in. I've only driven it a couple hundred miles since getting it back and it hasn't happened again. I still have the stock tires on it.

I know this doesn't answer your question about the tires, but I agree that it is unlikely it's your t-case since i'm have the same problems with a 4x4.

Not the tires...

MikeRi24 said:

thanks for the info! i got it back from the dealer, and they swore up and down that was the problem, so i pulled the 4x4 fuse at the advice of them, and guess what? it still does it!

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I have 265/70/r17, no issues from the tires. (I had a shifting issue, it would shift incorrectly going uphill, but that was resolved)

How was it resolved?

motorhead19 said:

Sounds like the problems I was having with my 03 4.0L 4x4.

Under hard acceleration I'd have a loss of power and the engine would just rev, or on the highway trying to pass the thing would jerk and buck. I was afraid this may have been caused by my tires, 265/70/16, and I didn't want the dealer to void my warranty, so I stuck a set of stock tires on it before I took it in. I've only driven it a couple hundred miles since getting it back and it hasn't happened again. I still have the stock tires on it.

I know this doesn't answer your question about the tires, but I agree that it is unlikely it's your t-case since i'm have the same problems with a 4x4.

Click to expand...

I take mine to the dealer with big tires, no problems. This Ex and the previous, no issues. What was your isssue (sounds like seals)

Donner said:

I take mine to the dealer with big tires, no problems. This Ex and the previous, no issues. What was your isssue (sounds like seals)

Click to expand...

I just wanted to be safe (every dealer is different), plus I had the tires, so it was cheap insurance. I originally brought it in for the tranny problems, but when it was all said and done:

- new ring and pinion in the rear
- new valvebody in the tranny
- new fuel sending unit
- 2 new cats and associated O2 sensors
- flashed the pcm with update

Only 60k on it and very well maintained ( I'm **** about maintenance) and all under warranty! I've never had a vehicle with so many problems at such low mileage. I'm beginning to hate this truck......

It'll be okay...

That's a pretty extensive list for 60K... and it must be frustrating because you take great care of your vehicle... And you're right, each shop is different. But usually they're pretty fair (especially since they modify vehicles too. It would be awkward if they gave you grief, and yet they service their own mods.

My list of repairs is pretty short... I do admit my other vehicles (Exs too) never had any issues of note. This 03 has had a few... I bought it new. The only time, IMO, that I would trade out is if it kept me stranded at the side of the road too many times. Even then, F150 or Mustang

The dealer I am going through (where i bought it) is like THE best knows Ford Dealer in the area, and now they wont even talk to me again until i take my tires off, and they still swear up and down thats the problem. I have had this thing in 7 times since i bought it in August for various problems, and have barely put 3200 miles on it. Im about to go and tell them to buy it back because this is getting rediculous

MikeRi24 said:

The dealer I am going through (where i bought it) is like THE best knows Ford Dealer in the area, and now they wont even talk to me again until i take my tires off, and they still swear up and down thats the problem. I have had this thing in 7 times since i bought it in August for various problems, and have barely put 3200 miles on it. Im about to go and tell them to buy it back because this is getting rediculous

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Wow, that's gotta be frustrating. I hope it's under warranty or at least the dealership is absorbing some of the cost! With as many explorer's there are out thereyou'd think they'd know what's going on. I had my tires on for 15k miles before the tranny problems, so it's hard to say if it caused it. As far as the dealer is concerned, it has only had stock tires on it.

If you don't have the stock tires, try getting a used set to throw on there and see if it stops. I know the used tire place by me has lots of 235/70/16's and sells them for $40 each installed. I'm currently looking for another set of rims to put my 265's on so I don't have to keep mounting and unmounting. At least you'll know whether or not it's the tires causing the shifting problems.

Is this their warranty?

MikeRi24 said:

The dealer I am going through (where i bought it) is like THE best knows Ford Dealer in the area, and now they wont even talk to me again until i take my tires off, and they still swear up and down thats the problem. I have had this thing in 7 times since i bought it in August for various problems, and have barely put 3200 miles on it. Im about to go and tell them to buy it back because this is getting rediculous

Click to expand...

Is this the factory warranty or extended warranty? The problem might be that you know as much or more about the vehicle... and they're giving you a hard time.

They don't have the option to decide which vehicle is covered by the warranty and which is not. Did you say this was the service mgr that made the decision not to assist you?

MikeRi24 said:

thanks for the info! i got it back from the dealer, and they swore up and down that was the problem, so i pulled the 4x4 fuse at the advice of them, and guess what? it still does it!

Click to expand...

Yep, they are wrong.
Theres no way it's your transfercase if you yanked the fuse!
That pretty much isolates the transmission.

Sounds like you just have a lemon man!
(check your state laws to see if your covered under lemon law maybe.)

I would go to other dealerships if possible and get some Free estimates or let them take a quick diagnosis of the problem.


My neighbor also had a problem similar to yours, it turned out to be a transfercase or transmission problem,something to do with the fact that the T-case is built into the transmission...which is a BAD idea Ford did.
He had STOCK tires on his exploder too.....


Theres plenty of people with AWD mountaineers and explorers that have oversized tires, off-road every weekened and play around, and NEVER have problems.
Im telling you AWD systems are usually EXTREMELY dependable.
It's one of those things you almost never hear about, unless it's product defect.

But for the ACTUAL 4x4 T-case to have problems....that's another story.
Im not sure how the Explorer rep is....but I know most trucks have a reputation for failing 4x4's....(usually due to vaccum hose or minor electrical problems, or gear problems.)

But AWD's usually are made of steel 99% of the time and never fail.

I am having this same problem, I would describe it as "chugging" while accelerating going up hill. My warranty is up so I haven't brought it in because I don't drive it up in the hills much. I had my transmission worked on (bad solenoid block, I had that replaced). I also have larger tires (265/70 R16). I also changed out the fuel filter and got no change. I have about 88,000 miles on mine, 4x4 V8 EB. I would like to know what the problem is cause the winter season is here and I will be driving it up to the snow.

Motorhead19: what did the dealer do to you explorer? Did they change any parts?

1 V8 Merc: What was your neighbors problem?

Anyone?

Thanks,

I've had the exact same problem on my 02 xlt with stock tires. Seems like under hard acceleration it detects that rear spins a bit faster than front and therefore engages 4x4 because of our Auto 4x4 system. I don't think shock loading the transfer case like is any good. I solved this problem by doing the brown wire mod. Now i can roast the tires no problem. I've never experienced any overdrive problems that people mentioned or anything. I just have a 9 amp switch hooked up and i didn't go the relay way cause i didn't see the need. I dont think the coil draws more than that. Nothing ever warms up so it's all good : . When doing the mod though, keep in mind that there is two brown solid wires. It's the thiner one you need to put a bypass on. The thicker one controls your rear windows. Anyone tried putting an lsd in a 02 with the independent suspension?

Hi. I have the same problem and have suspected that oversized tyres were the problem. Where did you get with this?

I have been told by the dealer that the 4x4 module is faulty, but I doubt that this is the problem.