Hmm, maybe it is just normal and we are over reacting. My howl as I call it is so slight it can't be heard once I turn on the Howard Stern. Good thing my shop won't call me back. Now I see why I only paid $450! LOL

 

does anyone know where i can get a set of 4.30's for the 9.75 rear diff?, found 4.10 but want a bit more for the 35

 

Don't know about any 4.30s but I have seen some people get 4.56s.

 

Mbogosia,

What I am hearing is very slight so I am chalking mine up to the fact that the 4.10 may inherently make a bit more noise vs. the 3.55. I mean we are creating about 200 more rpm at 65 mph than we were. Even so, when I return for my drain and refill I will make sure the installer goes for a ride with me and checks everything out real close before resealing. I really believe these guys will stand behind their work so I am trying not to panic yet.

Keep me up to date with yours.

FTO

 

No,its not normal! Its only going to get worse! I thought the same thing but the noise kept getting louder and louder.You need to take it back and have them fix their mistake,ASAP!

 

i had the same thing in the past on a different vehicle, when i put in 4.10's. what my problem was that i didnt set the pinion depth correctly, so i messed it up from the get go.

 

Well I called the guy and like every shop/mechanic he started feeding me lines of B.S. He said it was normal for a little noise. He said that me switching the fluid to Royal Purple was the issue. He then finally agreed to look at it if it got worse. I hate people.

 

you gotta get the guy to listen to it ASAP...the whine will make you go CrAzY!!!

 

Okay...for the other side of this...

I'm kind of curious as to what effect this has on the fuel economy of the truck...

Anyone with stock tires and wheels and the gear change care to comment?

I'm just thinking how Ford doesn't put these things in stock for a reason, just curious as to the trade off here.....