Same size tires two different brands

[pelliswolf]

Hi everyone. I'm new to the group and I have a question. I have a 2003 Mercury Mountaineer. It was making a banging sound as I drove and would get louder the faster I went. I had brought it to Aamco to get repaired. Back in late Nov early Dec and they replaced the lower ball joints, the differs and the drive shaft. Two weeks later I had the same problem again. This time they told me it was my transfer case and that having two different brand tires even with the same size caused the problem. Is this true?

 

[Mbrooks420]

Yes. 4 matching tires. Same brand, model, and size. Not sure why changing the ‘differs’ and driveshaft temporarily fixed it, however.

 

[pelliswolf]

The drive shaft broke and they said the differs were worn out. But why would that matter? I thought as long as you have the same size your fine. I thought brand shouldn't matter.

 

[Mbrooks420]

They aren’t the same size.

 

[pelliswolf]

So you're saying for example that a Goodyear tire size lets say 235/16R35 And having a pair of Bridgestone 235/16R35 are not the same size? How?

 

[Mbrooks420]

Those aren’t real tire sizes. But no, they wouldn’t match in circumference.

 

[swshawaii]

Agree, where do you see R35 profile? What are the ACTUAL tire models and size numbers printed on the sidewalls?

 

[pelliswolf]

I was just coming up with numbers. The tire sizes on both brands are P245/70R16. So you're telling me even if the sizes are the same one of brands will be smaller than the other? Is that what I'm getting? Because I never had a car with AWD before.

 

[chefduane]

Tires will differ in circumference between manufacturers. Go to Home Depot and buy a 10' 2x4, then go to Lowes and buy a 10' 2x4. Are they going to be EXACTLY the same LxWxH? No. There are minor differences even though they are both marked with the same size. Tire sizing, and keeping the same manufacturers tire on the same axel matter A LOT in AWD vehicles.

 

[Mbrooks420]

Yes. They will not be the same size. Doesn’t matter if they are labeled the same numbers. Unless they are the same brand AND model they will not match in REAL size. At the very least you need to buy 2 NEW tires. With AWD you ONLY buy an exact matching set of four tires.

 

[pelliswolf]

So I F'ed up my transfer case by having wrong tires on the Front. Great!!!

 

[Mbrooks420]

That would be correct.

 

[pelliswolf]

Would that also explain the binding issue I was having too?

 

[swshawaii]

Just one thread linked below, there are many.

4x4 Tire Myth?

 

[Mbrooks420]

Yes. The binding is from your axles turning at slightly different speeds.

 

[Turdle]

Yup
Go to the tire manufacturer's web site, select your size and look for the "revolutions per mile" column. Then go to a different brand of the same size and compare the revs per mile. Now subtract the difference and see how hard the diffs and clutches were actually working. \

 

[pelliswolf]

Thank you all for the info and knowledge