Hey guys I am in Iraq and don't get much time on the net or I would use the search function for this. I have an 03' F-150 4x4 w/ 4.6. It has the 8.8 w/ factory limited slip, 31spline in the rear and 8.8 reverse in the front . I did my gear oil change right before I left for here and found out that my spyder gears are toast. I figured that while the shop had my rear end torn up(no pun intended) that I would throw some 4.11's in to give me some power and milage back that I lost when I put the 31x12.50 SSR's on. I am looking at the Detroit true track locker or a worm gear style locker. Am I going to see any negetive effects other than the added cost of the gears. Thank You

Oh by the way I have 3.55's in it currently and they look brand new, no apparent damage.

 

on a 4x4, you have to do BOTH axles. chances are only the rear spyder gears are toast. expect to pay around ~$1500 for both axles. otherwise, if you only do one axle, and attempt to use 4WD, you will break the transfer case.

 

Thank you for the info. Just as you mentioned I figured that the fronts were probably fine but it is due for a oil change when I get home so I will check that out. The only worry for me is that I will drop gas milage worse that what I am getting now which is 12.5 avg. w/ out the chip on and 14.5 avg. w/ it turned on and running prem. I was quoted around 1600 if I remember correctly but it also included a detroit locker. I am not sure if you were including that in you estimate. Thanks for the price window thought because I wasn't sure. I am dealing w/ the same shop that I always send my stuff to so I am confident that they wouldn't try to pull a fast one on me. So your from lakeland! I just ordered a set of Trucks Gone Wild. One of the guys I work w/ isn't to far from there.

 

no problem, i didn't factor in a locker, you may not need it unless you offroad frequently. you can reuse your current stock limited slip. also, the 4.11's will not hurt your gas mileage, if any, it will improve in town, and stay about the same on the highway. if you can, specify for them to use Precision Gears. Precision cuts there own gears, unlike everyone else who uses cuts and recuts that are from China, and of subpar quality imo.

 

hey man thanks for the work over seas!

But i just wanted to throw this out there. If you ever plan on going with a bigger tire id either gear for that now of wait till you get that tire. better to do it once than twice

I.E. I ran 285/75/16 on my 99 4.2 F150 and could have put 4.10's easily and had a very enjoyable ride. But now Im running 36" TSL's and the 4.10's wouldnt have done much for me there so id have to go up to 4.56 or 4.88's. I hope that makes sence.

Thanks man be safe!

 

it sux that they don't make a 4.30 for both axles. that would actually be an ideal ratio for 35'' tires. anyone have a clue as to why they don't?

 

I have been wondering if I am going to go any bigger w/ a lift or tires but I just cant see it w/ the gas and all. As of now I am going to get a Buell to combat the gas prices and maybe keep some milage off the swampers. I didn't really think that the 4.10 would hurt my milage any because of how much topend I still have when I am on the highway. With my chip on and the topspeed limiter off I have hit over 115. The shop also told me that I could reuse it but suggested that I go to something that is a little stronger like a worm gear style or whatever the detroit are.

 

well just to poke at you alittle more. Im not sure what engine you have. and im not sure what MPG you are seeing but i just calculated mine up an i got 13mpg running 36's and stock 3:55 gearing on a 4.2L V6 . so when i do go up to 4.56's im hoping to see 15-18

 

I have 4.10s, Ford Motorsport in the rear and Motive gear up front....also went with the FMS TruTrac locker in the rear, I am running 33x12.5 bfg mt's and I get about 12 around town and 15-18 on the highway, I also have the hypertech 1715 on premium, air force 1 intake, 75 mm tb and a magnaflow si/so exaust, if I didn't drive with such a heavy foot mpg's would be much better I'm sure...overall no problems, no whining, shimmy or shudder, and the locker is worth it's weight in gold, even around town, keeps from peeling the inside tire in a turn when pulling into traffic in a hurry. BUT>>>> be carefull in the rain , it will whip around mustang style in a heartbeat<<<< best benefit I have noticed is when cruising , the truck doesn't down shift near as much, if ever, going up grades such as tunnels and overpass's .....forgot to add, I have the 5.4

 

FYI, if you decide to reuse the stock limited slip be sure to get a clutch kit put in it. As the clutches wear they let the side gears and axle shafts move a lot which is probably why your spiders are toast.

 

Thanks for the info yall, I have the 4.6w w/ a diablo sport programmer, AFE intake, Throttle body spacer(I know its a piece of **i#, got it before I knew about this forums) and currently have just a turndown after the cats. I was getting around 13.5-14 w/ the chip in performace mode and 12-12.5 w/out the prem. fuel and timing turned back. I am looking at Precision Gears 4.10s w/ a detroit locker or tru trac, I am not sure which locker is better.

 

whatever locker you choose is not as important as the brand of gears. make sure you go w/ precision, nobody else cuts their own gears, and there is no real true standard of quality, whereas there is w/ precision. you do not want problems down the road by installing anything inferior to what you have now.

 

Sweet Precision it is!