tires mismatched?? help please

[rainbow9]

I am in the process of replacing tires on my 2003 4x4. The truck has the auto 4x4 and anti lock brakes. I replaced the 2 front tires. The tires on the truck are 245x75 16. I have replaced the 2 front tires now brand new with 245x70 16's. When I now drive the truck I feel the auto 4x4 kicking in at speeds over 30mph or a whinning sound that sounds like the auto 4x4 is engaging.

Question; is the slight difference in size making this much of a difference? The old tires on the rear are 245x75 16 mastercraft. The 2 new fronts are 245x70 16 general grabbers.. this is what could be causing the computer to sense a difference and engage the auto 4x4? the truck was perfect before changing the tires..

thanks ahead please help

 

[Ronin8002]

Yes, that is exactly the problem. Not only are you mixing old + new tires, but mixing sizes and different brands on top of it, all of which add up to be your problem . You need to get 2 more General Grabbers in the same size.

In the mean time you can pull the 4x4 fuses to keep the auto 4wd from kicking in. Do a search in the 2002-2005 forums for the phrase "Brown Wire Mod"

I am in the process of replacing tires on my 2003 4x4. The truck has the auto 4x4 and anti lock brakes. I replaced the 2 front tires. The tires on the truck are 245x75 16. I have replaced the 2 front tires now brand new with 245x70 16's. When I now drive the truck I feel the auto 4x4 kicking in at speeds over 30mph or a whinning sound that sounds like the auto 4x4 is engaging.

Question; is the slight difference in size making this much of a difference? The old tires on the rear are 245x75 16 mastercraft. The 2 new fronts are 245x70 16 general grabbers.. this is what could be causing the computer to sense a difference and engage the auto 4x4? the truck was perfect before changing the tires..

thanks ahead please help

 

[MtExplorer Guy]

YES, it makes that much of a difference, either do the brown wire mod or get a matched set for the other axle, bad things could happen if you run it to long this way!

 

[MrBean]

wheel speed sensors detect different speeds from your different tire sizes and its gonna try to match them and that is why your 4X4 is kicking in

 

[roush9799]

Even with 4 new tires, if they are different brands, they will most likely be off size enough to cause problems.