4.11 Ring and pinion

[Jsmith3912]

I recently did a a differential rebuild in my 94 k1500 and I getting a high pitch whirling noise over 30 mph. The races bearings and carrier are all new. The pinion bearing preload is set to 19 in lbs and backlash is at .005. The gear pattern is below. Figured I’d see if anybody has some insight as to what is happening here

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[pressureangle]

The old guys I learned from always set the gears back in with the *coasting* side pattern matched up as closely as possible to the way it came out, or it would always whine or howl. I've always done it that way myself and never had a noisy one. New gears get a new pattern, used gears get their old pattern. They love each other where they were.

 

[Jsmith3912]

Sorry I failed to mention its a new gear set. But I’ll take note of that, thanks

 

[Erik the Awful]

The pinion bearing preload is set to 19 in lbs and backlash is at .005.

That backlash seems tight. What's the spec?

 

[Jsmith3912]

that’s for asking I just looked up specs and 2 cut gears vs 5 cut gears have different specs I’m looking for .006-.010.. I’ll make the adjustments and follow up thanks

 

[Erik the Awful]

I only know a little bit. I just wrapped up setting all the specs on my Mustang's replacement 8.8. I'll swap it in this weekend and see if it makes noise.

 

[Schurkey]

The backlash specs on my 10.5" full-float axle were .003--.012, .005--.008 preferred.
There's no mention of the gear "cuts", so whatever would have been OEM, I guess.

The actual backlash on my axle was .013--.014, it varied about .001 around the ring gear. The carrier bearings had zero preload when I took it apart to install a Truetrac differential.

I put the backlash right back to .013-.014, but added appropriate preload on the new carrier bearings.