I just replaced the right rear BFG Radial TA tire on my 71 Charger R/T because I ran over something and ruined the tire. This tire was 10 years old and had about 50% tread left. I did not replace the other rear tire that also was 10 years old and had 50% tread left. The front two tires are also BFG TAs and are the same size as the rears (235 60 15). The car now handles really odd and feels loose and sloppy. Kind of like something is loose in the steering but I checked that and that seems to be OK. Should I have replaced both rear tires instead of just the one? Being that the old ones are so old, could the new one be even a different rubber compound and cause the behavior? Need some opinions regarding this.
Thanks

Well obviously buying two tires would be better. You might try putting the new tire on the front to see if drives better even though thats counter-intuitive.

Think also about when the other three tires wear out--then you will probably buy four right? If you buy another tire now when the other TWO wear out you have to buy two new ones......

New tires will ride "squishy" for a thousand miles or so. I just put 2 new rears on my F350 and same thing. Also, I drive big rig and for the first 3,000 miles or so it is really squishy. We put tires on near the end of summer so as to have them broke in by winter. Something else to think about, tires do have a shelf life. After about 6 years they are broken down and should be replaced anyways. The rubber breaks down. Really important on motorcycles.

If I have to, I can get another new tire for the other side but I really don't want to spend another $130 if I don't need to. Tomorrow I'm going to give Discount Tire a call and see what they think too.
I really appreciate you guys' opinions. I may also try switching tire locations (back to front) as you suggested and see what that does. Just really odd how the handeling changed.....
Thanks

Bet ya lunch a tire store says "replace in pairs"; not necessary unless MAYBE a traction-control system is so extremely sensitive that a TINY amount of OD messes with it.

I'm sure that they will recommend replacing them in pairs because they get to double the number of tires they sell but I'm counting on them giving me the "true skinny" regarding my handeling issue. However, they won't be the only ones I ask...
Thanks

Give it a bit of time. When we put new steering tires on big trucks we have to exercise caution for a few thousand miles as they are a bit greasy. Same as on a motorcycle, after you put new tires on a bike you better ride careful for a while.
People don't generally notice it on a car.
BTW, 10 years is a bit long in the tooth for tires to be mounted and in use on a car.
You did recheck torque on all the lugnuts though?

Sheldon

Try replacing all 6 (single rear axle) on a big truck. Gets really greasy. Then pull triples. Ohhhh yeah, makes you need a pry bar to remove the seat. Just repalcing the 2 rears on my pick up and it made it a little twitchy. It made wider turns and just seamed to not be as responsive to turns. When changing lanes on the freeway, it seemed like it didnt want to go, then all of the sudden there I was and now I was trying to recover from an oversteer condition. Now the tires that I took off were really wore, past the wear bars. The new tires were 265/75/16s and were Michelin LTX M/S. Really nice thick tread. The new thick tread is what did it.

Maybe you have a sure grip in your rear? If you do that will cause a funny feeling and wear out your sure grip quicker.

I hope you only drive your R/T around town below 50 mph on those 10 year old tires. If you’re out there on the highway driving at 65 or 70 mph you’re an accident waiting to happen. Your R/T deserves better.

I just replaced the tires on my Super Bee because of age. They had less than 6,000 mile on them and looked like new. The car was in storage for eight years. I don’t trust any tire over six years old.

I checked with the folks at Discount Tire today and they suspect that the problem is that I didn't replace both rear tires at the same time (that's what I thought they'd say) and that the other tire is 10 years old and still has 50% tread and is fighting the new tire for control....... They suggested buying another tire and "trying it out" to see if that helps. I think I'll do a bit more investigating before forking out yet another $130.