correct, but the noise could also be from improper bearing pre-load. its kinda tricky to get the pinion pre-load just right without the correct torque wrench... and then if you go too far, the crush sleeve is worthless. thats possible where the issue is.

 

usually the whiing is a improper set up. like contact pattern , pinion to far away or to close or backlash is to to much or to little. the preload is in in-lbs so dosent take much to get there and very easy to overshoot it.

 

Its probably a little too late now that its already done, but does anyone who went from 3.73 s to 4.56 s have any before and after 0-60 time comparisons. I have been trying to get some more performance out of my truck after i put on the 35s, but I've already done a CAI, exhaust, and a custom tuned programmer. I wont pay the $1700 to do gears unless there is an evident difference in performance. It has been mentioned that there is no difference in seat of the pants feel, which is not a big deal if the 0-60 times are quicker. Thnx

 

I put on 35's in May and I really notice the loss in power and the fuel mileage drop. Those are two things I'm hoping to make up with the 4.56's.

 

all said and done, how much did it cost you?

 

x2!!! i feel no power loss in my truck either and i have the 3.73 gearing with 35"x12.50R20 pro comps. i have no prblem at all when i'm getting on the on ramp. and the only thing i have is edge programmed to level 2 and magnaflow performance exhaust.

 

06FX41992 - Do it period. This will be the single best thing to do to your truck. The truck will move easier, get up to speed faster. Haven't done a comparison 0-60 but I would recommend it to anyone who is thinking about doing it.

 

this was one of the best mods that i did to my truck after putting 35s on. before it was always downshifting and struggling to hold speed..now its normal again

 

I have always looked at changing gears not as a "do I want to do this" but a "you have to do it". Your truck came from the factory after years of testing and setting it up. It was designed to run a certain RPM at a certain speed. It was designed that way so the tranny, engine, tcase, diffs etc will work how they are supposed to.
When you go up in tire size you throw all that off so now your truck is not working at its optimal performance or even how it was designed. To me this mod isn't about power or MPG or anything it is about getting the truck back in order so everything works the way it is supposed to.
Just because you "can" do something doesn't mean you should. I mod all my trucks but I try to do it in a way that won't throw off everything the Ford engineers spent all their time lining up. That is the reason aftermarket tuners allow you to adjust tire size it calibrates the speedo and helps the computer run the truck right.
Again just my $0.02 but why would you want to spend all that money on lifts and tires and programmers and not do the gears which enable the truck to get the most out of those mods. Kind of a waste to do the mods in the first place if you aren't going to let your truck take advantage of them

 

Never thought about that, great post.

 

anyone that says they dont notice a power loss is just fooling themself.

 

There is a big different in the "seat of the pants" feeling, you won't notice it as much in light driving (although you will notice it isn't working as hard) but stomp on the gas or hook up a trailer and you'll know.
From the best I can tell (using only videos I have taken in the past), 0-60 is almost two seconds less than what it was with 3.73s and 35s.

 

With the gears + larger tires and no recalibrated speedo, my truck actually thinks I'm going faster/further than I really am. Pre-gears w/ 38's had my speedo thinking I was traveling shorter distances however. With that said, regearing really is a must, and is well worth the expense.

 

yeah but you guys gotta remember, Ford 's have that stupid *** Torque management so thats y ur not tellin that big of a difference, even those chips dont cancel out half of the maps running in the computer for spark/torque management. Its not like in the good ol days where when u stand on it the throttle opens and the only thing holding back is the power of the motor!!! When u get a custom tune and see what all is goin on when ur drivin it will blow ur mind, and make u think "wow no wonder it has no *****, and y my gas mileage sucks!!" its constantly moving ur timing + - 15- 20 degrees to control power. And the bad gas mileage, check ur mileage with a gps instead of ur speedometer cz mileage will be different

 

wrong!!