"singing" in rear end???

[TWJ]

I don't know if I'm being over-sensitive to noise in my car but I think I have a new one...

There seems to be a "singing" noise coming from the rear end at about 45mph and then again at 65mph. "Singing" is the best way I can describe it, maybe ""humming" or "whirring". There is no "clunk", "thump", "squeaking" or the like. It does not seem to correspond to being in a particular gear or to cornering or anything else I can relate it to, it just seems particular speed related.

I have looked at other posts and sounds like it could point to bearings or cv's but the other symptoms don't seem to be there. ????

Could this be as simple as old/bad rubber? Out of balance wheels? My tires are more that 10 years old (I know, I know...I NEED new tires) but have good tread on them as the car is only driven a couple of thousand miles a year. I did have them re-balanced last year and they where quite bad as they had to put a lot of lead on them to get them right.

Any thoughts/ideas/suggestions would be appreciated!

BTW the car is a '72 911T, pretty much stock. The 915 trans is a 5-speed.

[Flieger]

Tires.

[RWebb]

good tread is worthless unless the rubber grips the road - 10 year old tires are dangerous

the noise you hear is not singing, it is screaming

[TWJ]

Is the old rubber (or out of balance) creating the "singing" noise? Or?

[Flieger]

Sounds like it hits a harmonic at those speeds. That says balance. 10 year old tires say that imbalance is in the tires. Might be a flat spot or imperfection in the construction.

[dshepp806]

New sneakers needed....


Doyle

[TWJ]

Thanks much everyone!