4.10 Diff Whine - How to Quiet

Has anyone had success with fluid additives during diff fluid service to reduce the insane whine that a 4.10 rear and can cause.

Between 2k and 3k rpms at most speeds over 45mph, I want to put a bullet in my skull. The whine is exacerbated by the stiff 95A diff bushings that turn my rear subframe into a tuning fork.

that's because you went with a 95D diff bushing, has nothing to do with the final drive it self.

Can’t find the original post, but the guy who swapped to a ford 9” had success reducing sound by partially wrapping the front subframe bar with sound deadening.

Probably won’t get rid of all the sound but might help.

omgzirra_exe wrote

that's because you went with a 95D diff bushing, has nothing to do with the final drive it self.

I was afraid of this. Looks like I’ll live with it…
(I didn’t chose the diff bushings, prev owner had it done).

If it bothers u that much change it back to stock rubber/foam bushings.

I think eventually I will. I like the 4.10 but the whining is so loud at some rpm’s when it’s not fully loaded

I'd prefer quiet diff but my 4.44 come from reputable shop with disclaimer - some diffs are quiet and others not, b'cos motorsport loose bearings etc. Whine is exactly at allowed highway speed 90 km/h, higher and lower disappear. More hot summer day and less cold winter.

I installed alu bushings in the subframe and the differential two years ago, and got the famous diff whine. This was with the OEM diff with about 100k km.

The car has no rear seats and is a clubsport/track car, so i liked the noice.


But last year I Installed a new fully rebuildt diff unit with motorsport bearings and a Drexler LSD and 3.65 final drive, and absolutely all the diff wine disappeared.
To my disappointment.


A worn diff, or a differential thas has not been put together 100% properly can couse diff whine.

Mandersm wrote

I installed alu bushings in the subframe and the differential two years ago, and got the famous diff whine. This was with the OEM diff with about 100k km.

The car has no rear seats and is a clubsport/track car, so i liked the noice.


But last year I Installed a new fully rebuildt diff unit with motorsport bearings and a Drexler LSD and 3.65 final drive, and absolutely all the diff wine disappeared.
To my disappointment.


A worn diff, or a differential thas has not been put together 100% properly can couse diff whine.

Solid trans mount can bring some of that whine back.

put two strips of sound deadening on the subframe above the diff, it helps

Headers and straight pipes will also help hide the diff whine sound.