Had my 4.56 gears installed Friday, cant wait till the break in period is through so I can really test things out. Right now I'm kinda babying it a little more so everything sets right, I guess according to the tech who installed them they need to set right or something before I can really floor it or put allot of stress on it, now whether or not its true thats another story but its only a recommended 200 mile break in period so it not going to bother me any. Really though I can tell quite a bit of a difference though with them in, the truck seems to have a bit more get up and go to it. I just filled the tank today so I'll have to wait and see how the next few tanks go to see whether or not its helping the gas mileage or not. Only thing left is the headers now, which will probably be my Christmas present this year...

 

The best way to "set" a new set of gears is with a series of heating and cooling periods. For the first 150-200 miles it is recommended that you not travel more than 15-20 miles without stopping to allow the gears to cool. No high revs during this time at all - baby them and absolutely no towing. From about 200-500 miles you can gradually extend how far you travel without the having to stop to cool them. Again during this time, don't push 'em too hard and if you must tow, light loads and for less than 30 miles.
At 500 miles it is important to do a fluid change to get any shavings out and to inspect the gears for proper break-in/wear. After this fluid change, if all looks ok, drive that 'summbiotch like you stole it!!!

 

Now I read this, guess I gotta check in more often on the weekends... Oh well, I babied them for the first 200 miles, no whining or anything, I did have to make a few long trips though so my 200 mile break in period that the tech told me is through. I dont tow anything, and I will do the 500 mile fluid change, I was going to do one anyways later on. I still haven't laid into them at all, but the truck seems to get up to speed allot faster now and freeway driving is a breeze...

 

I would like to know how they work. Please keep us informed Im thinking about doing the same with my 03 QC 4.7, but I do tow a heavy boat so thats why.

 

Great mod for oversize tires and/or towing vehicles. Go for it...

 

Where did you order your gears from? I'm looking to get some installed on my truck, but I'm not sure where to look. Thanks.

 

Moe's Performance, Air Ram, Randy's Ring & Pinion, 4 Wheel Parts to name a few good places...

 

I got mine at 4wheel parts. The gears were around The gears were around $300, they were going to charge $450 for them so learn how to haggle, the labor was about $350 and the new 3yr/36,000 warranty on all parts and labor was $200, I didn't want their 90 day warranty to go by and have something fall apart or break on me. Im loving them and I still haven't even given them a a true test yet....

 

I've been thinking about the same mod as I have the 3.55 gears and plan to occassionally tow an old car with mine. I live in Kansas City and get blank stares everytime I ask who might install a set.

 

I am near KC too, on KS side. Olathe. I went to the dealership. They did a great job.