I am wanting to install a set of 4.10 gears and upgrade to a limited slip diff. but don't want a wine or roar while driving. What kind of gears do you have and do they make a noise?? I think i am going to go with the ford limited slip unit b/c i dont' go offroading....just need better traction at the drag strip. Any insight would be appreciated.

justin

 

I vote for:
Precision Gear ring & pinion
Auburn limited slip

 

whether you have them or know someone that does....how is the noise going down the road?

......anyone else have any input on this question?

thanks
justin

 

Precision gears are good. U.S Gear makes a good set too. Mine are perfectly quiet; much quieter than the factory ones.

 

Just curious to know what gas millage you get? Did you origanally have 3.55 and if so then what gas millage did you get with those? I am getting about 300 miles to the tank now with about 70 miles of that being highway(15mpg normally).

thanks again
justin

 

Originally I had a 3.55LS, they were relatively consistent at 14/city -- 17/highway after break in (about 10mpg combined before break in). With the 4.10s it went down on the highway slightly and no worse in the city. A few mods later, and I'm back up to 14/17.

 

I had 4.10 gears put in our Expedition (which we no longer own) to replace the 3.55 non-LS that came from the factory. With the factory gears and over-sized tires I was running, the Expy would downshift to 3rd on the slightest incline. When the 4.10s were installed, the downshifts went away and fuel mileage actually went up. Unless you have a similar situation, I doubt you'll see a mileage increase. With the 4.6L, 4x4, Superchip, true dual exhaust, K&N air filter and airbox mod, we got about 20MPG on a long highway trip from Okla. to Virginia. Running around town, mileage was somewhat worse at 15MPG.

Oh yeah- the gears were perfectly quiet. Absolutely no noise whatsoever. The Auburn LS would occasionally "pop" but it was pretty rare. Traction was terrific.

 

Ok, i really don't understand you guys talking about noise coming from your gears.. any gear you get is pretty much going to work the same once broken in.. I'm driving around with 456's that I bought from west coast diff's but i've NEVER heard anything from my diffs, just my tires and exhaust...

 

It mainly depends on the installation. Find someone that knows what they were doing. I had a Ford dealership put the 3.55's in my Mustang and thay whine on coast ever so slightly. They blamed it on the Richmond brand gear I bought.

 

I have ran 4.56 percision gear and sierra gear and both were set up exact to spec. and pattern ran perfect and both had the whine with light on and off of the gas. I would use 8.8 Ford Racing gears from Summit in 3.55,3.73,4.10,4.30,4.56 all for 189.95, assuming factory would make a quiet gear.

 

precision gear and an auburn posi. love the setup from where i was prior-3.31 and open. but, they do whine. im bringing it in friday to get it reset. we will see if that fixes it. what a difference the posi makes taking off from a right turn, or left for that matter. before if the road was even the slightest bit wet i just spun that inside tire and didnt go forward as much gas as i was giving it. now, wet or not, i punch it, it goes. no more waiting for that tire to hook up.

 

Another Precision/Auburn recommendation here.

 

Precision Gear - Good enough for NASCAR, good enough for me!

Mine are also completely quiet. Make sure you have money left for speedo correction when you make the switch.

Ian

 

v6 runner, you said in your post that you ran 4.56 gears is that what you run in your v6 truck now? what transmission do you have?

 

I currently have 4.56's and nearing bald 265/70R17, so assume them to be 31's I have the 4.2 and 4R70 auto and I turn 2400 @ 70