Getting 4WD light after mismatched tires

[rowboat]

I tried searching for a few things and could not seem to find what I was looking for so I'm sorry if the question has already been posted... I just had my H&R springs put on yesterday and had everything aligned. I also had them put on my Summer tires. All tires have the same size - 225/40/18. But the front tires are a different brand than the rear. This shop is known very well for their superior suspension/alignment service.

So I drove home last night about 35 miles from the shop and when i got about 4 miles from home, the 4WD light started flashing. I pulled over and turned off the car. When I restarted, the light was no longer on. I drove the remaining 4 miles and parked it.

I started looking online I found that some AWD systems are picky about having different tire brands on the car. I am ordering 2 brand new tires to match the fronts. From what I undertand, that light may have turned off the power to the rear diff because of overheating.

My questions are: Have I done any damage so far to any part of the AWD system? Do you think that ordering the new tires will solve the problem?

[kwright997]

Do the front and rear tires have the same amoutn of tread left on them?

Tire brands shouldn't matter but if the front tires have say 9/32 left of tread and the rears have 5/32 then the rear tires have less of a rolling diamater.

That means the rear tires will be rolling faster then the fronts, which the transfer case will not like and yes this could cause damage.

I have personally seen a transfer case that blew apart internally because of this issue.

General rule with AWD vehicles. when you need to replace one or 2 tires, you need to replcae all 4 so that all 4 wheels have the same rolling diamater.

[rowboat]

Thank you for the quick reply :)

No, the tread depths are not the same. The rears are just a little more worn. I am thinking that i am just going to jack up the rear and put it on stands and takethe tires to get switched rather than driving it to a shop.

[astraelraen]

Do the front and rear tires have the same amoutn of tread left on them?

Tire brands shouldn't matter but if the front tires have say 9/32 left of tread and the rears have 5/32 then the rear tires have less of a rolling diamater.

That means the rear tires will be rolling faster then the fronts, which the transfer case will not like and yes this could cause damage.

I have personally seen a transfer case that blew apart internally because of this issue.

General rule with AWD vehicles. when you need to replace one or 2 tires, you need to replcae all 4 so that all 4 wheels have the same rolling diamater.

+1

Or, say if you only have to replace 1 tire because of a nail, puncture, etc. Sometimes tire places can shave a new tire down to the same depth as your old ones. While it kinda sucks to buy a new tire and shave 1/2 the life off of it... it's cheaper than buying 4 new tires.

[rowboat]

Gotcha. I will get the tires to match, no biggie. I just want to be sure that I am not ruining the car! Do you think that any damage has been done so far?