65 Stang gear whine

[zigmont]

I have a 3.00 8" rear in my 65 fastback that makes some noise between 35 and 55 mph under a load. When coasting or decelerating it is absolutely quiet. My guess is that the pinion bearings are bad. I am considering replacing both the pinion and side bearings and setting up the rear end again. My question is this: Once a rear end becomes a little noisy is that it.... and only new gears will fix it. Or can new bearings correct the noise. It's not really loud, but it's there, and I want it gone.

 

[gtss]

if one of the bearings is the source of the noise, then replacing the culprit will solve the problem however
gear whine can present itself like you have described also. in which case you likely would have to replace gears,
and while you are in there, this would be the opportune time to change ratios if you are so inclined

gtss

 

[D.Hearne]

You may as well swap gears too. Unless you want 3.00's. It's gotta come apart, might as well upgrade now.

 

[zigmont]

Gear whine

For what it will cost, I will probably try replacing the pinion bearings first. I can always add the new gears later if I need to. I will probably stay with the 3.00 because I am running a T5 with the 3.35 first gear ratio and 24" dia. tires. I've got plenty of acceleration in first gear the way it is now. I used to have a close ratio top loader with a 2.32 first gear ratio. The T5 with the 3.00 rear is like the old top loader with a 4.10 rear in first gear.
Thanks for the input.

 

[D.Hearne]

The pinion bearings are easy, just unbolt the driveshaft and then the pinion housing bolts, the shaft and housing will come out the front of the centersection. I doubt though it'll get rid of the whine, I had bad pinion bearings too in the 9" in my Comet, but no whining from it.