If it's set up right, no need to worry about break in any more than you would with a new vehicle.

If it's not set up right, you'll know real soon when she howls and then when you go in, you'll probably be putting another set in.

Unless you see leakage or go through the deep stuff or maybe really abuse her a lot, unless you just want to go back in, plan to leave her shut up 100K or so.

 

when i did my gear swap i put valvoline 80-90 in front and back. no synthetic. when that stuff heats up it gums up and breaks down eaiser than the conventional. at least thats what i am told my my diff guy. it dont matter what was in it that is what should go in it he says. but then again its your truck your money! you are gunna do what ya want!

 

It would be nice to check to see if my fluid has any water in it occasionally. When I launch my boat, I have to dip to the middle of my rear wheels. I don't think it is an issue (according to the manual), but it would be nice to be able to check every now and then.

 

That's not the case anymore. Ford recommends sythetic oils for their LSD's. They used to break down and gum up years ago, but not anymore.

 

Well I guess I can share my experience now that it's mostly done.

I dropped my truck off at the shop early Monday morning so that they would have enough time to get everything done before the day ends. I get a call around 11:00 that the used LSD I took a chance on was junk. They said that the adjustments needed on it would be past 3000 or .003's, and that would cause a lot of excess vibration. he recommended that they pick up a brand new unit from Ford for an additional $300. I really didn't have a choice since they had the axle opened up.

After that I get a call around 5:00 saying that it's all done and that they grand total would be $760. Roughly 2x the amount I was expecting to pay when I walked out of the shop.

They warned me that there would be some whining because of the ratio and because the gears I had chosen were Motives. There is some whining in spots around 40-55 but they seem to be going away. I'm also going by the strict break-in regiment, 3-4 heat cycles and 500 easy miles followed by fluids being changed.

I can definitely feel a difference in how it drives. It takes less effort to get up to cruising speed. It's pretty hard keeping myself from hammering it, but I don't want to screw it all up now.

I guess I can list all the prices I paid for everything:
Motive Gear Performance 4.30 R&P - $185 at Stage 3 Motorsports
Motive Gear Master Install kit - $79
Used ebay LSD - $78
6 quarts of Amsoil 75w-140 gear oil - $108
Labor, brand new LSD and friction modifier - $760
Total - $1210

I still have to go back and have them check to make sure it's still good and change out the fluids, so that will be another $80 in labor. Fun experience, hope I don't have to do it ever again.

 

Damn dude!
Price is alil steep but first time you get on it hard tho, that trucks gonna move like a scalded dog! It'll feel so much faster..atleast on the bottom end.
I used pennzoil 75w90front and 75w140w/friction mod. So far zero "whinning" or noise from my motives maybe it'll go away for ya! Im thinkin im closing in on 5k miles since install tho.

 

Punisher, how is your city & highway economy with the new gear setup? I know of a few 2wd friends that need to re-gear but don't want to experience drastic mileage drop.

 

I've only made a couple of trips with them, but I can tell you that MPG's will suffer. The RPM's are about 1800 at 55 MPH. I really can't give an accurate reading for a couple of weeks. I'm going to have to "grand ma it" for another 400 miles.