Should I replace 4.10s with 3.73s?

[Dave04]

I get about 15 MPG no matter what I do. Would the cost of replacing 4.10s with 3.73s be worth it? What would ball park cost be?

 

[S.Morris]

Seeing as you have a 4x4 I don't think you would ever save what it would cost to do the switch . The difference in mileage would be little unless you are empty all the time and even then I would estimate no more than 5%. JMO

 

[Dave04]

The truck has 150k on it had it sense 34k. It currently is my second vic. I drive it less than 6K a year. 10% towing. Plans for it is lift and engine mods. It is my toy.

 

[AH64ID]

You will never save the money at that rate, and it would probably cost $1500 or more.

With a lift and presumably larger tires the 4.10's are better paired with the auto than 3.73's.

 

[Dave04]

Ok thanks for the info... What about putting a locker in? Front? AH64ID are you a AH64 pilot?

 

[AH64ID]

I have always wanted to put the AAM e-locker in the front, just have a hard time justifying the cost.

Yes, I am a AH-64D MTP for the ID National Guard.

 

[Dave04]

What do you think the cost would be? I am an 11A in the ILNG.

 

[SnoKing]

Put some taller tires on it! Chris

 

[JJPage]

60 hp nozzles and SJR, 15 mpg may be all that's there...you can play with options, minimum TQ, adjustments like that. Since I installed the Arson III my mileage sucks, about like yours, no matter what I do.

I am re-installing Revo (from TNT) for the new owner, that may make a difference, we'll see.

 

[Dave04]

What will taller tires do? Less RPMs but more weight to turn.

 

[Motorhead]

If you are driving open roads empty then installing a set of FREE SPIN hubs will help. On all freeway driving with my free spins, i saw 1.5mpg better. If you go taller tires then stay with as narrow of a tire that looks okay. Wide tires cost fuel mileage. Do you have any added FUEL TIMING? Added fuel timing can help with mpg too

 

[Dave04]

What hubs would you recommend? Timing I have smarty jr. I also have a diablo power puck but didn't think I was gonna use it with stock transmission.

 

[Motorhead]

I am talking about the hubs like Dyna trak hubs that disengage the front axel from turning when not needed.

 

[Dave04]

Ya I know. Where is the cheapest place to get them?

 

[seafish]

Haha....CHEAP is not a word to use when talking about the DynaTrac kit. That being said, I recently installed the DynaTrac free spin kit with DynaLoc hubs and feel that there impeccable design and materials quality, and the fact that the entire kit is still made in the USA, was worth the extra coin. SpynTech or Yukon also make a decent kit for less money then the Dynatrac. I bought mine from George at 8lug Truck Gear...he sells both the DynaTrac and the Yukon, was willing to price match, gave me free shipping, answered plenty of my questions, both preorder as well as during installation when they came up...I would definitely recommend him if you are considering purchasing a free spin kit.

 

[Dave04]

Haha ya I saw the prices. What is the Dynalocs. Is that what allows you to lock them out?

 

[seafish]

The DyanLoc hubs are the actual locking hub that is made by DyaTrac for thier free spin kit. Technically, they are a more expensive, high quality locking hub. Though they also offer a less expensive Warn locking hub option for their kits. Obviously Warn (you HAVE heard of them, right??...lol) has ALOT of locking hubs out there with only a very small percentage of failures, but again I wanted the advantage of locally made and sourced parts as well as one that would fail in a locked mode versus unlocked mode in the rare case of failure. The 3 big choices (though IIRC there are even more then 3 kit manufactureers for our trucks) for free spin kits are the DynaTrac, Spyntech and Yukon,,,if you google/compare them, you will have LOTS to read. Everyone seems to be relatively happy with their choice of kit, as well they shpould be given the $$ involved.

In short, if you have the money, do not necessarily expect a financial payback in fuel savings (though that IS there to some degree), run oversized wheel/tire combos which subject the unit bearings to more stress then designed for, and also tow a trailer so that you could benefit from the use of 2wd LOW gearing while backing up, then you should seriously consider a free spin kit upgrade. Another benefit is a slight increase in ease of steering.

 

[MarkEkberg]

Easiest way to do it, is to find someone with the 3.73's that wants to swap to 4.10's and exchange running gear.

I did that on a Ford of mine. Some guy had 3.55 and wanted the 4.10's Both of us were very happy.

 

[SnoKing]

What will taller tires do? Less RPMs but more weight to turn.

Same effect as switching gears. Chris

 

[Motorhead]

I am going to be selling my EMS free spin kit soon. Have 35,000 miles on them with absolutely NO trouble. They just stick out more than the Dyna track.