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View Full Version : 4wd tire slip and tranny trouble


93Chevy
12-28-2009, 08:56 PM
Okay, this may seem like a ******ed question, but I'd like to get a few opinions here. I'll try to keep the question as concise and readable as possible.

While I was getting new rear tires on my truck this morning, my saleslady cautioned me about having tires with different tread depths in a 4wd truck. Her caution was that the tires with more tread would have a better bite than the older tires, which makes sense. The better traction of the new tires would make it more likely for the front tires (with less tread) to slip while the rear tires (with new heavy tread) did not slip. This difference in slip, while in 4wd, would cause the transmission to blow.

I hope that makes sense. Basically, I have two questions. First, is it correct to assume that if the front tires slip at a different speed than the rear tires, the transmission with blow. Secondly, how likely is that scenario? My front tires, while having less tread, are still very drivable. I'm not in 4wd very often, but I would like to get an idea if this has ever happened to anybody.

I know this may sound stupid and I'm sure everybody on here knows the answer except for me. I would like to say that I appreciate anybody who takes the time to answer me. :waving:

STIHL GUY
12-28-2009, 11:28 PM
im not sure about the tranny problem but would you be able to just rotate the tires that are already on the truck??

Gravel Rat
12-28-2009, 11:46 PM
The sales person is just trying to make a tire sale. You should always put the newest tires on the steer axle if you are using the same tread pattern front and back.

On a empty pickup truck your not going to see any problems with the 4 wheeldrive the front tires will have more traction 90% of the time because that is where the weight is

Your big concern is if the tires are mismatched side to side so if you had a 33 inch tire on one side of the axle and a 31 inch tire on the otherside and try use the 4 wheeldrive.

All 4 tires have to be within 1/2 inch or so in diameter get over 1 inch or more then you may have troubles.

hosejockey2002
12-29-2009, 01:23 AM
Sounds like a case of your saleslady is trying to impress you with how much she thinks she knows about trucks, and trying to get you to buy something you probably don't need.

The front and rear tires being slightly different diameters would only be an issue if you were to drive around on dry pavement in 4WD, which from reading your post it is obvious you are smart enough to not do that. Conditions that you would normally use 4WD in allow for enough wheel slip to negate the difference in tire diameters.

Furthermore, if you were to drive around on dry pavement in 4WD, it would stress the axles, driveshafts and transfer case but probably wouldn't affect the transmission at all.

Now, if your truck were full time AWD you may have a valid concern, but chances are your saleslady doesn't understand the difference between full time AWD and selectable 4WD like what you have.

deere615
12-29-2009, 10:06 PM
never heard that before I know you should have the same tires on an axle though. Matching tires in back and matching tires in front.

topsites
12-31-2009, 04:21 AM
Oh I tell you one thing...

After many years of trying to save a buck, I ALWAYS replace all 4 tires, with nice, new ones.
Only way to go, forget this 2 in front and 2 in back stuff, not saying I've never done it but it
has been some years, nowadays I always do the same kind of tire all the way around.

That having been said you'll probably be all right on that issue, after all if transmission problems due to
tire slippage were common I would imagine most 4wd's would be in the transmission shop a lot LOL

Because you're going to get as much going around corners in ways of tires turning at different speeds...
Every time you go around a turn your fronts are going at a different speed than your backs, because
the back tires aren't steering so they take the shorter path to where the front is leading, for sure.
How come if one makes a turn too tight the back runs over the curb, it's taking the short cut.

So I'd have to agree someone was likely just trying to make a quick sale, however the sales lady would have
been better off cautioning you on the effects of CONTROL and ride stability, perhaps comfort.
Why I say, always replace all 4.

But you'll be fine, just take it easy.

deere615
12-31-2009, 10:19 PM
Oh I tell you one thing...

After many years of trying to save a buck, I ALWAYS replace all 4 tires, with nice, new ones.
Only way to go, forget this 2 in front and 2 in back stuff, not saying I've never done it but it
has been some years, nowadays I always do the same kind of tire all the way around.

That having been said you'll probably be all right on that issue, after all if transmission problems due to
tire slippage were common I would imagine most 4wd's would be in the transmission shop a lot LOL

Because you're going to get as much going around corners in ways of tires turning at different speeds...
Every time you go around a turn your fronts are going at a different speed than your backs, because
the back tires aren't steering so they take the shorter path to where the front is leading, for sure.
How come if one makes a turn too tight the back runs over the curb, it's taking the short cut.

So I'd have to agree someone was likely just trying to make a quick sale, however the sales lady would have
been better off cautioning you on the effects of CONTROL and ride stability, perhaps comfort.
Why I say, always replace all 4.

But you'll be fine, just take it easy.

Yep I put 4 new ones on last year and 4 new ones this year and I too will from know on always replace all 4 tires together

93Chevy
01-01-2010, 07:35 PM
Thanks for all your replies.

I couldn't justify paying another $350 for the two front tires when they still had tread on them. I'm always a very careful driver and never use 4wd on pavement unless its snow covered and I'm slipping in the rear. I'm helping a buddy remodel a house in my spare winter time, so I'll just use part of that money to buy the new front tires.

360ci
01-02-2010, 06:21 PM
I agree, it's a sales pitch. Unless you're driving a newer Audi with that AWD of theirs, tire diameter won't matter between front and rear axle. I've always rotated my tires so they've always worn evenly, and replacing all four are most cost effective = less trips to the shop. I've consistently achieved 70K on BFG tires.

93Chevy
01-02-2010, 10:42 PM
I agree, it's a sales pitch. Unless you're driving a newer Audi with that AWD of theirs, tire diameter won't matter between front and rear axle. I've always rotated my tires so they've always worn evenly, and replacing all four are most cost effective = less trips to the shop. I've consistently achieved 70K on BFG tires.

I rotate my tires often as well, but when I bought the truck last year, one pair was a little more worn than the others, so I replaced the worse pair. I'll get the fronts replaced in a few weeks, after I take care of all my other winter bills.

USFGUY
01-02-2010, 11:09 PM
on AWD replace all 4.. otherwise.. keep same size tire and replace in front or rear pairs. On my dodge I replace front and rear at same time just for my peace of mind.

AWD really requires all 4 tires being exactly what the driveline was designed for. I wouldnt stagger sizes on them at all. But with 4wd I have seen guys run rears MUCH bigger but doesnt really hurt until anything until they shift into 4wd... then the fronts drag compared to the rear... not good on the driveline.

93Chevy
01-02-2010, 11:50 PM
Well, the tires are the same exact size, but the fronts have less bite because they're older and have a less-aggressive tread pattern.

Basically, I don't have to worry about anything.

Thank you for all your replies guys.

360ci
01-03-2010, 12:06 AM
on AWD replace all 4.. otherwise.. keep same size tire and replace in front or rear pairs. On my dodge I replace front and rear at same time just for my peace of mind.

AWD really requires all 4 tires being exactly what the driveline was designed for. I wouldnt stagger sizes on them at all. But with 4wd I have seen guys run rears MUCH bigger but doesnt really hurt until anything until they shift into 4wd... then the fronts drag compared to the rear... not good on the driveline.

Depends on the form of AWD, electronically controlled AWD on premium luxury cars will have an effect on different tire diameters, as it affects braking and accelerating (wheels will slip more, etc). On my Durango, which is AWD (Full time all wheel drive) the transfer case is built for changing individual wheel speeds. Should I decide to lock the axles together, then it might become a problem with gear and driveline durability, but only over a prolonged period of time in very low traction conditions. On pavement, I agree, it would tear the driveline apart only locking the axles together (4HI/4LO). I run 30" tires on my R/T. For a while I had a nail in one tire and I had two P275/60R17 tires on order, but nothing was available locally in that size. I borrowed two worn down P265/70R17 tires and placed them on the rear. With full tread they would have been 31.6" tall. I would say they were at a good 31" when I had them installed until I could get my new tires.

Most luxury AWD vehicles that I speak of only have tires that are good for 20-30K, so if the fronts wear faster than the rears, chances are both sets of tires will be near the wearbars anyway before it causes any problems, and a new set of four is installed. Trucks are meant to take abuse. I ran 31" tires on the back and 30" tires on the front for 1800miles with no problems, and the truck performed just as well as it did previously. The only thing I can think of is the speedometer reading might be off, but otherwise it's safe to do for short periods.

If you don't rotate and the tires don't have a high tread life rating, I wouldn't get too concerned, but it's a good idea to rotate just to have the same grip on either axle.

Accu-cut Lawn Care
01-06-2010, 03:55 AM
The sales person is just trying to make a tire sale. You should always put the newest tires on the steer axle if you are using the same tread pattern front and back.

On a empty pickup truck your not going to see any problems with the 4 wheeldrive the front tires will have more traction 90% of the time because that is where the weight is

Your big concern is if the tires are mismatched side to side so if you had a 33 inch tire on one side of the axle and a 31 inch tire on the otherside and try use the 4 wheeldrive.

All 4 tires have to be within 1/2 inch or so in diameter get over 1 inch or more then you may have troubles.


You are incorrect. The "Lady" is too. It puts strain on the transfer case, transmission, and differentials when 4x4 is engaged and tire sizes are not the same. Though the front and back tires may be the same size numerically; they are not really the same. I would especially not risk it on a chevy drivetrain. You are fine, however, if you very rarely use 4x4... and only in very slippery "I just got stuck and need to get unstuck" type of terrain.