Can tires become out of balance?

[S2GART]

Without losing any weights, can a tire still go out of balance over time? In recent times the ride in my car has become rough as in vibration from the wheels. The car really hasn't sat for relative long periods of time. In past years the car sat for 3-4 months through the snowy wiinters here in CT. However, this year we have had relatively next to nothing for snow. Also with the temps being rather mild, I have been driving the car off and on. So, I can't see it being flat spots from sitting for long periods of time. I start feeling this vibration at about 50 and it doesn't go away as speed increases. I can feel it in the front and back. It's an up and down feeling, again, similar to flat spots, but she hasn't really sat for that long.

I am hoping that it's a simple matter of needing rebalancing, versus having to buy new tires because of flat spots.

Thanks.

[KTL]

Absolutely they can go out of balance with age. Even with uniform wear, tires still have issues as they get older.

Try rebalancing them. Tech may even have to deflate them, break the bead seal and spin them on the rim. If they don't balance well, then junk them and get new shoes.

[Joe Bob]

Aged tires along with worn shocks or other components can contibute to tires going out of round.

[Smoove1010]

Here's an anecdote: We just purchased an '87, the tires had lots of tread, and there were balancing weights in place, indicating a proper installation. Going by the date stamp, that installation took place 14 years ago! Last week we installed new Eagle GT's, had an alignment done, and the difference in ride and handling was night and day - a vast improvement. Nearly all vibration was gone, the remaining vibes I'm attributing to a warped rear rotor, which will be dealt with this week along with a grab-bag of other projects, once my shipment from Pelican arrives...

[T77911S]

what brand of tire are they?
have you locked them up putting a flat spot on them?

i have noticed that with cheap tires these days, especially kumho, just sitting over night they will flat spot, but....after about 5-10 minutes of driving it will go away.
sitting for a month or longer, it may or may not go away.

if you are going to let the car sit for a period of time, put it on jack stands.

[pete3799]

Could also be a broken belt in the tire.
Before balancing jack each corner up and place an object (spray can etc.) so it just touches the center of the tread and spin the tire. Any irregularities in the tread will easily be seen.

[tobluforu]

It's cheap to have tires balenced, give it a shot.

[rnln]

yes

[djcdmv]

Originally Posted by pete3799

Could also be a broken belt in the tire.
.

Had this problem once. I bought some used tires to put on an Infiniti that was coming near the end of its lease. Left the shop, next day they were out of balance. Took it back and the tech couldn't believe the other tech did such a bad job balancing them. He rebalanced and off I went. Same thing happened. Turns out my neighbor ended up buying my car when my lease ended and he was so aggravated he put new tires on. It was at this point they determined the belt was loose.

[ivangene]

my 996 tire
tire2 - YouTube

[S2GART]

I have never locked them up and they are Bridgestone Tires. I will get them rebalanced and see if that does the trick.

I too had thought about the shocks, now don't throw stones at me, but the car's shocks are original. Shortly after getting the car (Oct 2005), I had the tires balanced by the local Porsche dealer. While the wheels were off the tech. looked the suspension over for me. He said that they were the original parts with no signs of leakage and there wasn't a reason to replace them unless the car gets floaty over bumps and dips.

The rear shocks appear to be pretty straight forward to remove, but the fronts.... now that's another story.