just had 3.42's installed and now getting a howl at 50 and up, is this just the new gears, or are we talking shims, The gears are from Richmond, but they were labeled economy?

 

It's common for new gears to make a howling/whining noise.

 

Yup, I installed Richmond 3.73's in my 87 TA and they were quit noisy at first but then quieted down a lot after around 150 miles or so. I then switched to a heavier 120-140W gear lube and there is almost no noise now. Only when cruising above 45 mph or so, but when I let off the throttle or just bairly get into it, the hum goes away.

 

I wsa told to run synthitic oil, maybe if I go back to gear lube it will be a little better, I'll let go for awhile and see.

 

Well, the 320 (120-140W) that I ended up using is a synthetic, but I don't know if it was that or the fact that it is a much heavier lube that helped quiet the gears down.