I have a dilemma. A few years ago I sold my 1995 Blazer to my now 18 year old nephew. He has been buying his tires at Walmart and going to Sears to get them installed. He thinks the Sears guy is the best because he lines up the lettering and gave him shorter stems. I had a bad experience with Sears and will not go there again.

I have a friend that works for Goodyear and is my mechanic. I have an excellent working relationship with this place and feel that they have never steered me wrong or ripped me off.

Here is the problem. My nephew only buys two tires at a time. I was always told that with a four wheel drive vehicle that all the tires have to match up in type, size and tread. My guy said that if I buy my nephew two rear tires that are not very similiar to his front tires that his transfer case may lock up. He also does not want to put the tires on after that vehicle has been sitting out in the cold weather.

I need facts please. I know feel like I have to buy him four tires. The Blazer has never handled well in the snow and I want him to be safe. But I really cannot afford to put four tires on his car when my husband needs four right now. He would kill me if he found out that I paid that much for my nephew and not for him. But I can't leave my nephew in a lurch or put him in an unsafe situation.

What do I do?

 

you should be fine if you are buying similar tread pattern and size tires

 

He wants to run all seasons on the front and winter tires on the back. I just spoke to another tire guy and read something on the internet that says that this wil lock up the transfer case.

 

If it is a 4wd truck, winter tires just on the back sounds silly...

About locking up the transfer case. If the tires are different outside diameters, something has to give. If you are only using 4wd on loose/slippery surfaces, then the tires will just slip which is not exactly what you want to have happen. On high traction surfaces, something else will give, mostlikely the transfer case.

If he's going to drive around in 2wd mode all the time, this won't be a concern, but I doubt that is what is going to happen here.

And regular all season tires on one end and snows on the other is not a good idea. It is best to keep the same type of tire (summer, all season, mud, snow, etc) on all of the wheels so that you don't have differences of traction which can be unpredictable.

I do have to question why it is your responsibility to put tires on your nephews vehicle... Doesn't he have parents?

 

Tell him to put the tires with the most tread depth on the front. he will need more traction to turn and to stop, that is handled by the front tires.

Haveing bald tires on the back only means he can't get up to dangerous speeds quickly, and it can lead to fishtailing around corners if they fall below the tread wear bars, or if he is going to fast, and fishtailing will happen even with the best tires if he is going too fast.

I understand the desire to help your nephew out, however your husbnad comes first, you have to live with him.

As for the different tires on front and back. As long as the tires are the same size it doesn't matter. Think of a transfer case like this. The puspose of a t-case (transfer case) is to tkae half of the engines power and split it equally to the front and rear axle. This means that both the front and rear axle are turning at the same speed. Now if we put 40" dieameter tires on the rear axle, and 20" diameter tires on the front axle, the front tires will turn twice as fast as the rears. However the t-case is sending turning both the front and rear axle at the same time. Something has to give/break. On a slippery surface, like snow, the traction breaks, on dry pavement nothing gives so the t-case breaks.

Now if he is driving in 2wdr all the power is going to the rear axle, no power is going to the front axle and its not turning, so you could run 40" tires in back and 20" up front and not break anything. By the way, those tires sizes are for example purposes only. Niether will fit on your truck without major modifications.


Let me bring up another scenario. What would your nephew do if you weren't around to help? He would learn to drive on the tires he has. I highly recommend having you or your husbnad take him out to a vacant parking lot covered in snow and teach him how to drive on it, with the tires he currently has on the truck.

The only time he must have new tires is if the wear bars are showing. In plain english, if the tires are legally bald. Have your Goodyear mechanic show you what legally bald means. I cannot do it on the web properly.

Here is a link by How Stuff Works that might help explain the purpose of a t-case.
Our Blazers have Part time 4wdr t-cases, unless he has the AWD t-case.
http://auto.howstuffworks.com/four-wheel-drive2.htm