I just had Ford Racing gears installed in the rear of my 02 Screw. The gears whine between 40-60mph. Its loud enough that I can hear it over the radio. Also, I can't notice that much of a difference with the torque. The truck is a 4.6 liter with 33" tires. I had the master install kit installed also. I thought I would notice a considerable power difference since I went from 3.55 to 4.56 gears. Any help would be greatly appreciated. Thanks in advance.

 

I thought I remember reading somewhere that ford racing gears were not for "quiet running vehicles"...Either way the higher the ratio the more noise tendency. I was under the impression that stock tire size, assuming 4x2, were something like 29" maybe 30ish. Your combo is fairly close to stock ratios so I dont think you'll notice much of a difference. Was the work done by a shop that specializes in drivetrain components? Maybe they werent installed correctly? I too have 3.55 gears that are starting to whine pretty good and was thinking of going 3.90 yukons w/ stock tires and master overhaul kit. Let us know what you find out.

 

I have been driving the truck everyday to work n back to see if the noise changes. It now seems to be only from 50-60mph. My buddy installed the gears. He is a ford tech from a local ford dealership in the area, so he does know what he doing since he has done quite a few. The truck is a 4x4. I have a whole other differential with yukons already installed for the front which is going in on saturday. The backlash was set at .008 and I read a thread that this would cause more noise than having a setting around .012. Ford Racing calls for .008 to .012.

 

You know you have to check more than just backlash... right?

 

you have to check gear mesh and the back lash.

 

How do you check gear mesh?

 

Yeah we did check both. After 500 miles we are going to double check everything again and I am going to run Amsoil this time. I read a thread that said running this over a conventional oil may make a difference in gear noise.

 

you use yellow gear paint and paint it on 3 of the gears and then u skip 3 and paint another 3 and so on, until u have done it all the way around the ring gear. Then u spin the ring gear about 10 full turns, then you can see how the pinion is meshing with the ring gear, by were the paint has worn down. you may have to add pinion shims if its not meshing properly.

 

idk if it matters but when i first got gears in my stang they were loud but after about 1000 miles they quited down like they had to wear in..and they were done by a diff guy that happends to be a family friend....fyi they r motive gear gears 373 in a 8.8

 

I am hoping they quiet down a little more. I am taking a trip this weekend so once I get back were are going to pull everything apart and check everything again. We will see then how everything looks.