I bought a truck with new virgin tires on the front/rear axle and worn tires on rear

My shop guy says I will take out a rear end because of the tread difference.

About 3/4 inch more tread on the new tires/vs the old tires.

3/8 inch on the top and 3/8 inch on the bottom = 3/4 inch.

Say it's 9 feet around the face of the tire.

The new tires at 9 1/2 feet and the old about 9 feet only.

The new tires are on the front driver and equally matched.

The old tires are on the rear driver and equally matched.

Anybody have any experience with this?

Some say no problem.

Others say that over time it will wear out the rear ends.

 

You say "my shop guy". Sounds like someone you trust. Why are you second guessing him now? Let's see, the cost of 4 new tires vs. 4 new tires & a lot of mechanical work. Hmmm....

 

The inter-axle differential will receive the excess wear, not the drive axles.

 

We did this many times when buying ten new tires at once was not affordable.
The rears run on two different shafts.
The troubles start when the tires on a single axle or set of duals are different sizes, even then mostly just the smaller of the two blowing. If all 4 are the same no worries.
Ran many miles like this while saving money for the other 4 tires.

 

The average circumference of tires on the first axle should be approximately equal to the average circumference of tires on the second axle. Rather than mix and match to make this happen, wouldn't it be smarter to trade the older tires for four new ones?

Without matching both axles, the front drive will probably run warmer. Of course, it usually does run a bit warmer because of the inter axle. Heat causes wear. Why take a chance? Someone will buy those used tires.

 

I know a lot of guys that do this with no issue.

I have also heard that it can lead to issues. Personally I just rotate tires between 150,000 and 200,000 miles.

 

If you are driving around with the "differential" locked then yes... Damage could occur. Otherwise there is a reason why it's called a differential! That reason is because it is designed to accommodate the differences in rotating speed that occur during cornering or when tire sets are not evenly worn.

 

Thanks, that's where I'm at. I don't have the money for the second matching set of virgins right now.

I will match them when I get my first money.

The rears running on two different shafts thing sounds right unless their locked which they will never be except a few feet and slow to get past a slippery spot or something. Thanks

 

I don't have the money for the new matching set of virgins until I run several thousand miles.

 

That's what scares me.