I have an 06 Supercrew with a 6" fabtech, duals, k&n, and EDGE programmer. I have 325/60/r20's and want to put in new gears, a rear locker, and possibly a rear set of airbags for towing my 72 CJ5. I was wondering if anyone out there had any suggestions on setup and products. I'm not trying to be lazy but i cant for the life of me find anything in the air suspension market for an F150 that has a 6inch lift already, and i was leaning towards 4.56 gears and wanted to know your guys opinion on brand and if it is the right choice for wheelin and towing with the size tires i have. I probably dont need a locker but i want one.

 

By the sounds of what you are running I would definitely re-gear. And I would go with a min of 4.56's possibly 4.88's. I think 4.56's will be just fine. If your truck is 4x4 you will need to go with 8.8" 4.56 reverse cut up front, and check your axle tag on the rear, but I am guessing you have a 9.75 in the rear.

A question I do have for you is does your truck already have limited slip? If so a locker is not that much different and you really would not notice much if any difference at all.

I would recommend either ford racing gears, yukon gears, or precision gears.

And with the set you have the 4.56's would definately make your truck come alive again. It will not be such a dog after the re-gear. For the most part your rpms won't increase to much. You will probably see an increase in fuel mileage as well.

To find your rpms

(new gear ratio) X ( old rpms)/ (old gear ratio) = new rpms
E.X.
4.56 x 2000 = 2445 aprox. rpms
3.73

And to find out what axle you have on the rear you can check one of two places.

1. Axel tag this is a little metal tag attached to the rear differential.
It will read something like this 975 73 LS.
The 975 in this tag means you have a 9.75" rear end.
The 73 means that you have 3.73 gears.
The LS is the designation for the Limited slip option.

2. Is the door code.
This can be found under the axle designation on the factory door sticker. If you have the H9 designation you will have the 3.53's with limited slip. If you have B6 you have the 3.73's with limited slip. I can not recall the other designations right now.

Along with gears you will need a crush collar, shims, bearings, pinion nut, seals, and oil. And if you do have the limited slip make sure to buy the bottle of Friction Modifier. Also depending on which gear oil you go with you may not need to add the friction modifier as it already comes in some (this is as stated on there bottles, however I feel more comfortable adding it just in case, better safe then sorry). I know Royal Purple and Lucas Oil already have it in them. The gear oil for the front is 75w90 and the rear is 75w140.


This link is very informational and gives you some more info I may have over looked.
Gear Swap Write Up Rev 1

This is the link to where I got my gears:
http://www.accuautoparts.com/

Hope this helps! Good luck on your decision.

 

Another important point is the break in period.

Quoted from ring-pinion.com

New Gear Break-In
"Do we really need to break-in a new gear set? I have heard many people say "When I bought my new truck no one ever told me to break-in the ring & pinion." Whenever we are blessed enough to afford a new vehicle, we take it easy on the engine for the first few hundred miles. While we are pampering the engine (probably for the last time ever), the ring & pinion set goes along for the ride and gets a chance to break in before we hammer the throttle.

In most stock vehicles with stock tires there is seldom a risk of a burned gear set. For those of us who modify and use our trucks, there many situations that can contribute to burned gear syndrome. Motorhomes, towing, tall tires, and high numeric gear ratios (4.56 & up) can all generate a lot of heat and cause the gear oil to break down. The greatest damage to a new gear set results when it has been run for ten minutes or more during the first 500 miles and the oil is very hot. Any heavy use or overloading while the oil is extremely hot will cause it to break down and allow irreversible damage to the ring & pinion.

In order to make them run cooler and quieter, new gears are lapped at the factory. However, they are not lapped under the same pressures that driving creates. The loads generated while driving, force any microscopic high spots on the gear teeth back into the surface of the metal. This is called "work hardening". Work hardening is similar to forging in the way that it compresses the metal molecules into a very compact and hard formation. This can only be accomplished if the metal surfaces are lubricated and the gear temperature stays cool enough that the molecular structure does not change. If the temperature of the metal gets hot enough to change the molecular structure, it will soften the surface instead of hardening it. This may seen like a balancing act but it all happens easily & passively as long as the oil keeps the gear cool while it is breaking in. Some of the synthetic oils on the market today can help a gear set live longer. I've had great success with Red Line ®, Torco ®, and Richmond Gear ® synthetic gear oils. These oils will continue to lubricate at temperatures where many crude oils break down.

Even with synthetic oils, I still recommend the following procedure for breaking in a new gear set: After driving the first 15 to 20 miles it is best to stop and let the differential cool before proceeding. Keep the vehicle at speeds below 60 mph for the first 100 miles. I also recommend putting at least 500 miles on the new gear set before heavy use or towing. During the first 45 miles of towing it helps to go about 15 miles at a time before stopping to let the differential cool for 15 minutes before continuing. This is necessary because not all of the gear tooth is making contact until it is heavily loaded. When towing, the teeth flex to contact completely, and cause the previously unloaded portion of the teeth to touch and work harden. All of this may seem like paranoia, but it is very easy to damage the ring & pinion by overloading before the teeth are broken in. If you take it easy on a new ring & pinion and keep it full of high quality oil, it should last a lot longer.

With regards to limited slip additives, I have found that using too much additive can lead to premature gear wear. Use just enough to keep the limited slip from chattering but not more than 4 oz for every 2 qts of oil. It is a good idea to change the gear oil after the first 500 miles in order to remove any metal particles or phosphorus coating that has come from the new gear set. This is cheap insurance and a good time to discover any problems before they grow to disastrous proportions."

 

Thanks for the help Bro,

You are the third person who has said yukon which is what i have in my CJ5, I do have the 9.75" with 3.73 but i have been in some situations where i hope i would have noticed a limited slip rear end. Im deployed right now so i will have to wait till i get home to check it out but i think im sticking with 4.56 as opposed to 4.88. I dont plan on going any bigger with tires and i only tow the jeep maybe 4 or times a year. I think even if i have the LS Diff i will pony up for the locker just because. Any suggestion on where i can do some research on a set of air bags for the rear for towing. From what i can see it looks like it will have to be custom. I cant find anything online thats made for the 6 inch lift.

 

I do not yet, know as I am looking for the same thing for my truck. But 4.56's will do great, I am getting ready to put them in my F150. It is a good overall gear you will get back lost power and it will still have decent mpg's. And Thank you for your service its greatly appreciated what you and your fellow men are doing over there.

I will post if I find anything about the bags.

And I never did add that your truck looks sweet!

 

Koucho- thanks for your service bro.

I think you might want to rethink the locker in the truck if you are going to tow with it. I thought I read somewhere that all the strain from towing along with a locked rear end wasnt good for your drivetrain. I don't know this for a fact, just a word of caution.

A couple guys on here have lockers in the rear. I dont know if they tow with their trucks or not though. Klitch is one of them. Im sure someone will chime in and set this straight.

 

I didn't even think about the locker and towing, i would have thought it would have been ok but now im wondering. If you here any more about that let me know. As far as the air bags go there is a guy selling his F150 Screw on Ebay with a lot of nice work done to it. Hes got air and a 6 inch lift. I emailed him and hopefully he will send me how he did it. You can see them in one pic but you can't see any of the mechanics behind it.

Cheers Bro's

 

I currently have a thread started on the topic as well.

Here is the link:
https://www.f150online.com/forums/su...-air-bags.html

 

If all you are towing is a Jeep on a car hauler, and you don't want it to sag when hitched up, all you need is a WD hitch setup... Don't bother with the bags IMO.... If you are going to load up the bed only or tow a 5th wheeler then the bags are the way to go...

The WD hitch setup will distribute the tongue weight across all your axles and level you out for the most part..

Mitch