If this is a factory set up then there will not be any shims on the sides. The factory used select fit solid spacers that were between .220 and .260, no shims. If you have shims then this is not a factory set up.
I just realized that this may be a '65 or '66 rear end, which used spacers that were between .060 and .090. It's been a long time since I set up one of those and I can't remember if there was just one on each side or if there were more than one. I believe that it was just one per side.
Thank you. It's looking like I need to pull the cover and caps to see what's up.
Originally Posted by driveshaft-texas
did ANYTHING you have done change this -at all ?
Think about frequency … is it wheel speed or engine speed ? Try running the car in second gear up to the rpm the noise occurs in third. The fact it shakes the mirror leads me believe its not the rear end
And if you find clues its the untouched factory set up , I would leave it alone.....or plan on new gears/bearings.
Granted its too tight , but it has run many miles this way
A thought -if driveshaft runs pretty straight , the trans bushing/ slip yoke clearance could be excessive
Nothing I have done has really made a difference - except after I re-installed the factory axles; it appears the noise is minimalized until I drive the car enough to bring everything up to temps. Then its back to its noise at speed. It is definitely wheel speed - no question. RPM means nothing to the noise.
Right now I have no idea if this is factory setup or a PO was in there, so I don't yet know if it has actually run many miles this way as I bought the rear end used. And the mirror shake isn't excessive - yet still noticeable when looking at the image or you can feel it if you put your finger on the mirror.
And it has a new slip yoke (& u-joints), and I've had a M20 & rebuilt M21 in it with no noise differences.
How hot does the diff get after a drive? How did the fluid look when you drained it? Was there metal on the magnet?
It does get very warm, but I wouldn't at all say hot. I put in new gear oil and additive when I installed the aftermarket axles (about 800 miles ago), and now the fluid has blackened and the magnet caught very, very fine particles. Felt much finer than toothpaste.
David, I picked up some Prussian blue by Permatex @ NAPA. Not my preferred compound, but got a really nice pattern with it yesterday, so I buttoned mine up at 8 thou and will run it. And replace the frozen wheel cylinder I found yesterday!
I'd see what the pattern looks like.
I ordered some differential yellow paste form Amazon and it'll be here tomorrow!