Does anyone know who can possibly make some custom gears for our trucks? After crunching the numbers, Im tired of driving around town with the O/D turned off and ready to re gear. 4.30s would suite ME just fine provided I can get a ring and pinion made for the front. If not, I may consider 4.56s. FWIW, its a street queen that only hauls my 180 lb *** down the interstate to work and the grocery store a few times a week...

 

I think I remember a thread here about 4.30 reverse cuts, but I'm not sure it was valid.

I'm assuming you have a 5.4 - what size are those tires and what gears do you have now? Do you have a programmer?

 

^X2. I believe I've seen 4.30s somewhere, it just seems like a huge waste of money to go from 3.73 to 4.30.

- NCSU

 

I thought my sig had that info... 5.4L, 3.73s, 37x13.50r20s and a POS Gryphon.

The Gryphon was a slight improvement with power and keeping the truck in gear (once locked in above 40mph). However, there have been torque converter issues with PHPs stock tunes, making it a pain to drive around town with regards to locking into the commanded gear. Example: In a 35mph zone I have to get on it hard, accelerate past 40 for it to lock into third. Then I can slow down to 35 and it lugs 3rd beautifully.

I like tall gearing on all my toys (2 and 4 wheels alike) and the 3.73s have been doable with my light foot and highway driving. I would like to free things up a bit, however, 4.56s are just a bit low for my liking. 4.30s will bring things back to about the stock ratio. Taking into account the added weight of oversize tires, the truck will remain somewhat of a pig off the line. And Im fine with that!

So anybody know who can make the gears? If not, I guess its 4.56s....

 

Basic mathematical calculations and charts to back it would say otherwise

 

I was thinking of 4.10s, the other common gearing, not 4.30s, my mistake. It is a waste of money to swap 3.73s to 4.10 in my opinion. Still, even with 4.30s your MPGs probably won't increase enough for you to recoup the $$ spent on gears and installation. Many people want taller gears to get back some of the mileage lost when putting big wheel/tire combos on. If you're just looking to get power back and don't care about costs, that's not a concern for you then.

This is the only reverse cut 4.30 I could find, sorry.

http://completeoffroad.com/i-124654-...s-dana-60.html

How much highway driving do you do? There have been guys with 35s that rock the 4.56s no problem. If I had 37s, it'd be a no brainer to go with a good set of 4.56 gears.

Also, have you thought about trying a different tune/tuner?

- NCSU

 

I have thought about 4.10s, but you are correct... Its probably a huge waste of money.

All Im interested in is is nice compromise to make things more efficient. MPGs dont mean much, after all it is a lifted truck. As far as highway driving, its I do quite a few cross country road trips.

Forgive my ignorance, but is our front diff a Dana 60 as specified on those 4.30s you found? I appreciate the find!

As far as a different tuner, Im about ready to throw the thing out the window. However, I like the fact that it has re calibrated my speedo!

 

Unfortunately, no, it is not. People have done Dana swaps with our trucks, but I don't know what all that entails, or how much $$ is required.

Yukon does make a 4.11, 4.56 and 4.88 reverse cut gears for our trucks though.

I absolutely love my Troyer tune. Since you've already got the tuner, it's probably only run you like $50 to get him to write you a tune. It'll take a while since he's always super busy, but I think it's worth the wait.

Here's a basic gear chart:


Assuming you had 33s from the factory with the 3.73s that puts your RPMs @2469 (65 mph). This is in their "better fuel economy for highway driving at the expense of some acceleration and overall performance" category, shaded in yellow. It sounds like you really want something more in the black range, or maybe even on the low end of the blue range, which they say will "improve acceleration and towing power at the expense of some fuel economy".

So now you're running 37s, so a 4.30 (they call it 4.27) swap would bring your RPMs back up to 2520, about 50 RPMs higher than stock.

A 4.56 swap would bump you up to 2692, nearly 225 RPMs above stock. That still puts you in their yellow range. Once people start moving into the 38"+ tires, you often see them swapping to 4.88 gears.

Personally I'd go for the 4.56 or 4.88 to get the power back. But I'm not really concerned with fuel mileage or highway driving.

- NCSU

 

PHP is the only company that can write tunes for the Gryphon or any of the converted Edge products. Ive heard their custom tunes are good as well as Troyers. Might go ahead and put my name in the hat for some.

Thats the same chart ive been using and the numbers are within 30 rpm in real life (taking into account that chart represents a manual transmission, not an auto). Multiply the given rpm by .7 and that provides the rpms while in overdrive. Im probably going to do 4.56s because Im not willing to swap front differentials to make the 4.30s a reality.

 

Charts and calculations are one thing, common sense and experience are another.
I fly helicopters and I understand that you and I both have to stick to certain charts and calculations for determining aircraft performance, but real world doesn't always work out to what the book says either. There are always other factors at play. But your truck is completely different anyway.

Returning the gear ratio to "stock" with 4.30s will net worse performance than stock. Your truck is now a lot heavier, taller, creates a lot more drag, etc. Your wheel/tire combination is significantly heavier, you have a lot more rolling mass to get moving. You should gear LOWER than stock with a lifted truck and bigger tires.

On a side note, I have 35s and 4.56 gears and it is perfect in my opinion. Just under 2100RPM at 70mph, great driving around town. Plenty of torque off road and in 4x4. If I was running 37s I would have installed 4.88 gears.

With 37s and 4.30 gears, you are turning 1900RPM at 70mph in overdrive.
With 37s and 4.56 gears, you are turning 2025RPM at 70mph in overdrive.
The difference is very little on the highway as you can see. But there is a bit of help when you're getting moving from a stop and driving around town, with the lower gearing. I would never (and have never) spent the money to re-gear just so I could end up with "worse than stock" performance. Take it for what it's worth.

 

^^^

We could pretend my truck came with 3.55s... So 4.30s with 37s would be better than stock 32s and 3.55s... The 4.56s are within the ballpark for me, however I would prefer 4.30s as Ive always liked lugging a taller gear around on all my toys. Ive argued with my father on this. He wants to throw 3.73s in is 09 Shelby GT500 whereas I love the standard 3.31s! To each his own...

Obviously nobody knows of a place who can make custom gears which is why I called and will receive an official quote tomorrow on a 4.56 install. I heard this place usually runs around $1200-$1500.

You flying helicopters for a living or a weekend warrior? You are right about charts and number, especially in aviation. They are only as good as the guy behind the controls... BTW, Ive seen your truck on here before and have regretted not getting a super crew thanks to you!

 

To each his own is right.
I always re-gear my trucks lower than stock. With "normal" acceleration my truck will lock the torque converter in overdrive at 40mph, even if I'm climbing a hill. And it will pull steep grades on the highway with the torque converter locked, rather than constantly downshifting like it did with 3.73s. RPM at 70 is around 2100 and very comfortable for me.

I fly helicopters for a living. Currently I'm flying for a coal mining company, hoping to get into utility work in Alaska or flying offshore in the Gulf of Mexico (for the 14/14 schedule). My job here has me on call where I always have to be available, so I don't get to do any instruction or side work, and rarely get to take time off. I just sit around (in a BORING part of the country) and wait for my phone to ring. I moved out here from Oregon for this job, and my wife and I are desperate to get back to the Pacific NW.

 

Except that 32s are way lighter than 37s meaning the 32s have less rolling mass to get moving, making it easier for the truck to turn them.

But why pretend, you're truck didn't come with 3.55 and 32s.

Either way, I'd like to hear your thoughts once you finish the swap. I've been thinking about jumping to 4.56 but I only plan on running 35s and don't know if it's worth it.

- NCSU

 

Danville isnt too far from my current gig of flying DHL boxes out of Cincinnati. I was a CRJ line training captain for a while overseas. I spent most of my time in Africa and the Middle East working for a few CRJ upstart airlines. When the economy tanked, so did the foreign contracts.... Now its a Beech 1900 out of CVG every weeknight. Its only about 3.5 hrs of flying divided into 2 shifts which is nice and it allows me to remain within a *****ty tax bracket! I guess we should be thankful to still be employed as pilots in one of the worst times in aviation. Your on call situation is why I will remain an airline guy. Ill sit reserve for an airline when I have a specified block of reserve days/hrs and off days. You do any fixed wing stuff? I wish you the best in going back to the NW. Im hoping for the Southwest hiring pool to run dry and guys retiring before 65. However, it looks like Ill be waiting until December 2012....When age 65 retirements will take effect.

 

I realize that and already addressed it in this thread. I still would be getting 4.30s if the front could be done. Ill let you know what happens with the 4.56s