Anyone with a hemi, swaped from 3.92 gears to 4.56's?

[milehighguy]

mmm

 

[milehighguy]

dont want bigger tires........ yet! but the mpg and acceleration gains would be nice for now!

 

[bigtigga84]

Like the other dudes said previously, it will help mpgs and with how fast prices are goin up it just might pay for itself lol. Has been said before that the cost isn't justified for saving gas but that was before it was damn near 4.00 a gallon

 

[OlDirtyJohn]

i have 33"s on my truck and 4.56 gears. very worthwhile mod.

 

[chefred112]

I have 29.5" tires (275/60-17's physcally measured from ground to top of tire), started with 3.92's..then upgraded to 4.56's, loved them...then bowing to peer pressure, I changed them to 4.10's..they were ok but when a friend gave me his 4.56 gears after selling his truck, I threw them in and am loving it... only problem i now have is traction related at the track... with dr's or slicks..

 

[milehighguy]

hey chefred, nice videos! thats a fast gas powered truck! you see diesels do that but not to many gassers do it! so who wants to donate me some 4.56's? think they'll be okay for towing too? i have a small camper trailer apx. weight is 3,000 lbs. let me know your thoughts!

 

[chefred112]

..I tow my boat with it...

 

[Redtruck-VA]

Fred, that is a very nice boat! You have good toys..

 

[bigtigga84]

hey chefred, nice videos! thats a fast gas powered truck! you see diesels do that but not to many gassers do it! so who wants to donate me some 4.56's? think they'll be okay for towing too? i have a small camper trailer apx. weight is 3,000 lbs. let me know your thoughts!

You two wheel or four wheel? Might be a dumb question with you login in denver but figured id ask. I have a gently used rear ring and pinion, but I gotta get a front set too so these just been sitting around for 4 or 5 months.

 

[pavester]

im ordering 4.56s this weekend. got my tax refund,paycheck,and bonus in one weekend

 

[Trupiano]

Damn! Congrats Pavester! It's gonna be a whole new truck with those mods.

 

[milehighguy]

4x4 you dont buy a 2wheel drive truck in colorado! well unless you have something else to drive in the snow! i dont have that luxury yet!!

 

[bigtigga84]

Lol figured so.

 

[Torque]

4x4 you dont buy a 2wheel drive truck in colorado! well unless you have something else to drive in the snow! i dont have that luxury yet!!

Hey another Colorado guy, I'm just north of you in Fort Collins.

Cheapest I've found someone to do gears here is $375 an axle...$$$ Almost pulled the trigger on them last year till I read about the early shifting issue that can't be tuned out... damn 2003s and their padlocked shift schedule. Anyone know if that's still an issue for this year?

You're lucky with the 2004 that you'll be able to adjust your shift points.

 

[HemiSwapped06]

Almost pulled the trigger on them last year till I read about the early shifting issue that can't be tuned out... damn 2003s and their padlocked shift schedule. Anyone know if that's still an issue for this year?

You're lucky with the 2004 that you'll be able to adjust your shift points.

TCM is not adjustable, however the early shifting thing is part-throttle based. The shifts are based on engine RPM and when you change the gearing the MPH the shift happens at is lower. However its really not a big problem. With the gears it pulls itself to speed much easier, almost deceptively so. I went from 3.55s to 4.56s in my 06 and haven't touched the shift schedules. Shifts happen at the same RPM for a given throttle position that they always have. However to get the same acceleration as before you will be under LESS throttle, which will cause earlier upshifts, and give the side effect of increased MPG around town. My truck tends to lock the torque converter very soon after taking off from a stop ~20 mph, which further improves the MPG over stock.

With the 3.55s and 20s I took it to 120 MPH once and was at maybe 5,000 rpm.

With the 4.56s on 26" tall 245/70/R17 drag radials I once took it to 6,500 in 3rd, caught OD at WOT and pulled it to 6,000 in 4th, every bit of 130 mph. Should have seen the guy in the Mustangs expression as I drove by him.