TV tire wear and 4X4 transfer case risk

[dpam]

I learned something new today about 4X4 vehicles and tires, so I thought I'd share this with MOC on an FYI basis.
My TV is a GMC 3500 4X4 truck. My rear tires have worn about 3/32nds more than my front so I'm in the process of getting a tire rotation. My GM dealer service dept. told me that if your front and rear tires vary more than 3/32nds there can be some risk to your transfer case. On an average it costs $3K to replace a transfer case. The service dept. said that if there is more than 3/32nds difference in tire wear the transfer case could be going through excessive wear. I was told the dealership had a customer that had a difference of 5/32nds between his front and rear tires and his transfer case failed and had to be replaced. Apparently GM, and other truck manufacturers do not provide warranty coverage if the issue is caused by the tires. I'm not an expert, but I was told that the transfer case gears are affected when 2 tires turn faster than the other 2 tires, which is due to the significant difference in "32nd" size of the tires.

[CORattler]

Never heard of this.. not doubting you however.

[DQDick]

That's a new one on me also.

[mlh]

That would be true if you were using the truck in 4X4 while on the road. Mud or snow would allow enough slippage that transfer case wouldn't be harmed.
Lynwood

[bethandkevin]

What the dealer told you is only partially true. If I'm not mistaken, your 3500 dually has a two speed transfer case. That is to say, your choices are 2wd 4hi and 4lo. If you were to run your truck in 4wd on dry pavement, what the dealer told you is true. I've never known anyone that even mistakenly has done this. As mlh stated, anything on the road that would create a degree of slip will counter this. This problem is more common in auto 4wd and all wheel drive applications. To my knowledge GM still does not make the NV263 transfer case in a auto 4wd model. Just to illustrate how pronounced this can be, do what is called a rolling circumference test. Mark all four tires (outer duals and fronts in your case) at the bottom with some chalk or a tire crayon. Driving in as straight a line as possible, have someone count to ten tire revolutions, coming to a stop with one of the marks in the same position it started out in. Now go to the other tires and see how far the marks you made on the tires are from the bottom where you marked them. Anything more than two inches difference in ten revolutions will induce driveline wear and transfer case in particular. While working at the dealership, I was a driveline specialist and performed this test a lot on all wheel drive vehicles in particular, but it applies to four wheel drive as well. This is why it is important to not mix tire brands even though they are the same size. As for the dealership denying warranty on such a vehicle, I would find another dealer. He seems to be looking out for anyone but you as a customer. This would never have been denied when I worked there.

[bigskyjimmy]

Had 4WD'S all my life some with Fulltime locking diffs and Yeah you do not want to match different size tires front and back but 3/32-5/32 off front and rear ????? I call B.S, in my younger years with very little cash I mixed and matched brands and different degrees of wear and NEVER had a problem as long as they Are the same size tire and one end is not New and the other Bald, Heck even on my current truck I run TOYO's up front and Michelin's out back with No problems and besides the front is not engaged 90% of the time anyway, Just my experience of 35 years of 4wheeling

[mhs4771]

GM uses a disconnect solenoid in the front differential when in 2 wheel drive, so there is no drive to the front drive shaft from the wheels, thus no drive to the transfer case. The same would be true if you had the old style manual locking hubs which allowed the front hubs to free wheel on the front axles.
I ran two different size tires on my 05 215s rear duals and 245s front (wanted a little wider tire on front because of the Duramax weight). Sizes were close but not exact. Put a lot of miles on those tires without a problem, and even ran in 4 wheel drive at times during the winter commutes.

[steelpony5555]

It may be true but it may also be one of those things where it would take 500K miles in 4wd to do any damage.

[dpam]

I see my post has created some debate and identified some difference of opinion, which is fine and it is normal for everyone to have their own opinion. The purpose of my post was to SIMPLY SHARE INFORMATION that I was given from what I consider to be reliable sources. I guess I should have also told you in my original post that similar information was provided to me from Costco's tire department and 2 other large tire retailers in Canada.

PS - Kevin, my truck is SRW and not a dually

[1retired06]

Interesting. I have had 4WD trucks for 25 years, and never had any issue caused by tire wear.

[Phil P]

Hi

All of the previous posts have some merit.

However the dealer is correct and to back up this stamen look at your GMC vehicle manual and you will find a recommendation to rotate the tires every oil change. This prevents the problem.

I grew up in my father’s heavy equipment shop and then worked with him in the house moving business. The information the dealer is giving you is correct and it gets much worse when you applied the same information to an all wheel drive vehicle that is operating under heavy loads.

When we had to come out of a field with a house and needed to do so with the TV in all wheel drive if we didn’t sand the road so the front wheels would slip we word break something in the drive line because of the traction difference between the drive axels still on soft ground and the drive axels on pavement.

The fact that the tires have worn different sizes isn’t what voids your warranty it is not following the recommendations in the vehicle manual.

So my recommendation is to follow the instructions in your vehicle manual and listen to the dealer he sees the problems created by not following the procedures recommended by the vehicle manufacturer.

Now something else I just learned from my Chevrolet dealer.

If you have an extended warranty policy on your TV and you’re doing your own preventative maintenance like oil changes and tire rotations etc you are violating your contract and you extended warranty is void.

Phil P

[Art-n-Marge]

I keep records of preventative maintenance. If you have the receipts and records of the types of oil, coolant, fluids etc of your own work, this should not violate your contract or void any warranty. In fact it should help justify any failure to prove the correct things have been done to the truck. Going to the dealer for some of this warranty makes me squeamish. I forget the details now but I have been known to find they screwed some things up or tried to charge me for work they hadn't done and I've had to go back to have them fix it and I hate going back to have something corrected since it should have been done right in the first place.

I have read about trying to ensure keeping the brands, models and sizes of tires equal and I try and do that. I had a blow out on a Michelin tire, whereby I put the new replacement and the unused spare on one axle, while the other axle had the older more worn tires on it. I admit I did not do the tire size check (I'll have to check that out), but the newer tires are probably definitely larger than the used ones, but I don't know how much. I only use 4x4 when off-road and it's rare and I also think the transfer case would only have a problem with different tire sizes on a hard surface like pavement which I've never done. At least I'm gonna believe that since I don't want to buy all new tires all around, just yet.

[gmseller]

Well being a service tech for 23 years I can totally agree with this post. tires much match or you get what they call axle wind up. The front axle and the rear axle have to turn the exact same distance and any tire variation can change that. Thats why on any 4x4 you always change all 4 tires at the same time. Now obviously there can be a slight difference from wear more on one than the other and I am not sure just how much i would say excessive is. However if you drive around in 2 wheel drive you will never have a problem but if you use your truck in 4x4 much i would worry some. It will also depend on what your driving on, if snow or mud your going to get slippage from the tires and wont hurt anything. But driving on hard surfaces will not let the tires slip and that causes wear in other places such as the transfer case. Most transfer cases have clutches in them now and that would be what would wear first

[Phil P]

quote:Originally posted by Art-n-Marge

I keep records of preventative maintenance. If you have the receipts and records of the types of oil, coolant, fluids etc of your own work, this should not violate your contract or void any warranty.

Hi

Read your contract these guys are speaking from experience.

Your contract maybe different.

However just like GMC’s recommendation to rotate the tires every oil change by not following it you jeopardize your warranty.

If your extended warranty contract says all maintenance must be performed by qualified maintenance personnel then you must go to the definitions in your policy and determine what their definition of qualified personnel is.

Phil P

[bigred715]

I have heard from several members that have run considerable distance in high 4x4, including myself TOWING a 5th wheel and not doing any damage. Posted this as a question and everyone said it would do no harm. Tires were the same age on truck and rotated properly.

[Tom S.]

quote:Originally posted by gmseller

Well being a service tech for 23 years I can totally agree with this post. tires much match or you get what they call axle wind up. The front axle and the rear axle have to turn the exact same distance and any tire variation can change that. Thats why on any 4x4 you always change all 4 tires at the same time. Now obviously there can be a slight difference from wear more on one than the other and I am not sure just how much i would say excessive is. However if you drive around in 2 wheel drive you will never have a problem but if you use your truck in 4x4 much i would worry some. It will also depend on what your driving on, if snow or mud your going to get slippage from the tires and wont hurt anything. But driving on hard surfaces will not let the tires slip and that causes wear in other places such as the transfer case. Most transfer cases have clutches in them now and that would be what would wear first

Some of your post need to be clarified. With the transfer case in two wheel drive, there is nothing in the front wheel system to get 'wound up'. In order for wind up to occur, the truck must either be in 4 wheel drive or have a full time four wheel drive system. And since most sane people only use 4 wheel drive in poor traction conditions, any wind up that could occur is quickly released without harm. People do more harm driving in 4 wheel drive on dry pavement, by far. I have been involved with GM 4x4's since 1973, and know my way around a NP transfer case - unfortunately.

[gmseller]

sorry , you are correct there is no axle wind up if you are in 2 wheel drive. I guess I didnt make that clear

[Phil P]

February 8, 2014 12:36 EST

Hi

I just spent 2 hours in the manuals for my 2009 Duramax Silverado 3500 DRW.

All references are in manual 2 of 7 the transfer case control module has 32 parameters. Some of which are axel reference these are referenced all the time the vehicle is moving regardless of what mode you have selected for your 4X4 operation 2W or 4W H or L. The rest cover everything from clutch function to oil temperature (temperature not found in the transfer case section but in the body control module).

Seeing as how it would take days of reading find just how the module uses all of these inputs I haven’t gone much further that coming to the conclusion that if GM says rotate the tires every oil change they defiantly have a good reason for it.

Phil P

Disclaimer:

I only spent 2 hours reading the manuals so there may well be some errors in my understanding but the safe thing to do is follow the manufacturer’s recommendations.

[kdeiss]

I was told when replacing tires on a 4x4 besure to replace all 4 at the same time thinking for this reason

[Art-n-Marge]

That won't fly with my Roadside Hazard warranty. When a single tire on the left front of my truck failed. I moved the rear tires forward and put the remaining good tire as the spare under the truck. Then the new replacement and the existing spare (with no miles on it) went on the front axle. I haven't measured how much tread had worn, but I didn't even bother to ask American Tire to replace ALL the tires so they would be even.

I'll just make sure I never use 4x4 on pavement (I never have, and I never will, anyway). I try to replace all my tires when I replace tires just so I don't have to worry about it, even on my 4x2 vehicles. So far, there have only been two times in my driving history, I didn't do this. Besides the recent tire failure on my truck with the Michelins, the other time was when I got a nail in the sidewall on some almost new tires, so the replacement tire was not so different from the other tires (those were Kelly Springfields on a 4x2 SUV. I guess I've been pretty lucky, but I sure do try and follow the "all tires at once" philosophy. I have had other tire failures, but was able to have them plugged.