9in Ford Noise

[Cyclone03]

Ive seemed to have pretty good luck with setting up gears,so much so as I do them for friends with no noise problems. But,much like the cobbler with barefoot kids I can’t get my set up quite. I’ve put 3 new sets of gears in this one case and they all scream!
I said case because this weekend it dawned on me the screamer 1 was my old set ,including diff and bearings and retainer I swapped out of a C7 case into an N case it was quite in the old case. I have then over 5 years purchased 3 new sets of gears and installed in this N case all with the same results noise under load (drive side) quite in cost.
This past weekend I pulled it again and ran the pattern,dead center,as a matter of fact the gears had just polished the drive pattern into the gear and the marking compound verified the pattern.
Has anybody had a gear case that was just bad?   

[Falcon67]

I only use C7 cases and have never had any issues like you describe, even with used 4.11s or new 4.56 gear sets. 

[Cyclone03]

I only use C7 cases and have never had any issues like you describe, even with used 4.11s or new 4.56 gear sets.

That’s what is driving me nuts,I cleaned the rust off a set of gears and installed them for a friend and they didnt scream like the trouble I’m having.

To give you an idea of the noise,my Apple Watch has a Db meter at 75mph gear loaded 82db coast 77!

[winr1]

What brand are the noisy gears ??

Will try and find the several forums where folks had noisy gears that would not quite down



Ricky.

[Cyclone03]

Richmond,Summit, and now Eaton.

The Eaton gear had a test pattern when I got them that I matched as best I could.

[shady]

https://www.hemmings.com/stories/article/strong-and-silent

[gt350hr]

  Lance,
     Have you checked the "tail bearing" They do wear and "can" cause a load related noise despite a good pattern when checking or when removed to inspect. Even with a Daytona retainer and solid spacer it can happen.
   Randy

[Falcon67]

That’s what is driving me nuts,I cleaned the rust off a set of gears and installed them for a friend and they didnt scream like the trouble I’m having.

To give you an idea of the noise,my Apple Watch has a Db meter at 75mph gear loaded 82db coast 77!

That's nuts!  Way out of normal.  I typically use Richmond, Strange or Moser.  I never use Summit gears, heard too many iffy stories.   

[babybolt]

Heard that US Gear and maybe one other manufacturer are the only US made differential gears.

[Cyclone03]

  Lance,
     Have you checked the "tail bearing" They do wear and "can" cause a load related noise despite a good pattern when checking or when removed to inspect. Even with a Daytona retainer and solid spacer it can happen.
   Randy

Can’t rule anything out, but I’ve changed it twice,as well as all the other bearings.
It’s maddening.

[allrightmike]

My money says you have not forgotten how to set up a ring & pinion, it says the problem is in that case. Maybe pinion center line to carrier center line are out of spec.

[machoneman]

The case's dimensions may have shifted if it was used in say heavy drag racing/slicks, etc. Try pitching the same gears (lotsa work!) into a different case and see if they don't scream.

[gt350hr]

  Lance,
     Have you checked the "tail bearing" They do wear and "can" cause a load related noise despite a good pattern when checking or when removed to inspect. Even with a Daytona retainer and solid spacer it can happen.
   Randy

Can’t rule anything out, but I’ve changed it twice,as well as all the other bearings.
It’s maddening.

      Time to pass the case on to a drag race only ( no mufflers) car , LOL.

[70tp]

I had a case once that , no matter what gear except the one that came out of it, could not be made happy.    Got different case and all was easy