Hello all,

I recently swapped to a 4.10 gear in my 2005 Mustang GT. Following the swap, I now have a mild whine coming from the rear end when cruising anywhere from 45 mph to 65 mph. When I accelerate in between those speeds, or am driving faster or slower than that, there is no whine. I'm wondering if anyone has tried the "Damper Kit" (Part No. 5R3Z-3C246-A) listed in TSB 09-20-4.

Thanks

 

That usually means the pinion-bearing preload was not done right, or loosened up.

 

How did the gear pattern look? Did you take any pics? Did you use a new crush washer to set pinion preload?

 

Usually Ford 410s set up nice and quiet if within spec. I've done 4 of those and all good. Only trouble I have is with the 373s which are a little more difficult, but that was the first install and they whined. Here's a good site to peruse for a gear setup. https://mustangforums.com/forum/4-6l...-overhaul.html
If you can find an article by James Adkins, he also has some great information. If there's not too much mileage on the gears it may be possible to correct the whine by ensuring they are adjusted to spec.
I did try the dampers with the 373 but ended up taking them off and they are in an upper shelf in the garage. They do add weight to the car, but I found them ineffective.

 

All good advices here but if Motive gears were used then that is your culprit. They're just not good. lol

 

That is exactly what my first thought was but I couldn't remember the brand that people always said to stay away from (Motive).

Anyways, check the preload and recheck the contact pattern. Another possible culprit, although unlikely unless you lowered the vehicle, is the driveshaft pinion angle needs adjusting. .

 

Derf, I totally agree...if you're not 100% comfy to do the job yourself, let a pro handle this.