For anyone wanting more speed for your deuce

[m-35tom]

the 4.90 set would be useless in a deuce. do the math, these are for high hp hill climbers etc. there have always been other ratios for the rockwells, a higher ratio is used in the a3.
i have a shop in pa now setting up to make .69 od gear sets. this has been a long road, but maybe this time...............

tom

 

[joeypushjr1]

ok Stumps you got me there. i should have reworded what i meant. granted you lose soem power by upgrading tires but in my case throwing 11's on not losing nearly as much as that big a gear ratio.

 

[ClarkeF]

What is the stock axle ratio in the A2? Is the A3 axle a different ratio? I could see an A3 - which comes without an OD tranny benefiting...

Cheers,

Clarke

 

[stumps]

ok Stumps you got me there. i should have reworded what i meant. granted you lose soem power by upgrading tires but in my case throwing 11's on not losing nearly as much as that big a gear ratio.

I wasn't thinking so much of a 9 to 11 swap, as I was of some of the monster truck tire swaps that guys do... But ratios are ratios.

In any case, whether you change your top speed from 56MPH to 65MPH, by changing your tires, or by changing your gears, you end up with the same torque issues.

-Chuck

 

[adamsoffroadperformance]

I forget the name of the guy. But these gearsets were origanolly made for a customer who drove his deuce from L.A. out into the desert and used it as a motorhome. The guy bought 7 sets of gears and Russ did the install work for him. The guy has been running them for years without a problem. Yeah they are a little pricey but he hand machines all of them them he sends them out to be professionally surface ground which as said on the site makes them stronger and quieter and costs $$$. Russ has been maufacturing axleshafts and other parts like this since 1991 and has been perfecting things still. I don't know much about the Ouverson gears Randy does make some great stuff. I guess it depends on what you use your deuce for and how much $$$ you're allowed to spend on these types of things, I figured I'd post it here for anyone who may want or need something like this.

 

[adamsoffroadperformance]

I wasn't thinking so much of a 9 to 11 swap, as I was of some of the monster truck tire swaps that guys do... But ratios are ratios.

In any case, whether you change your top speed from 56MPH to 65MPH, by changing your tires, or by changing your gears, you end up with the same torque issues.

-Chuck

Yes you endup with a torque difference but you have to remember that if you install a monster tire on there that is a lot more recipricating weight than the origanol 9.00x20. This in turn will sap more power to turn versus a faster gear ratio in the axle the gears weight diff is minimal. Plus with a faster ratio there is less torque on the axle shafts versus the stock gear and bigger tires. so in theory it makes the axleshafts stronger/less likely to snap. As per brake upgrades there are disc brake conversions out there and if your resourceful you can build your own for much cheaper than the kits.

 

[JTugwell]

What is the stock axle ratio in the A2? Is the A3 axle a different ratio? I could see an A3 - which comes without an OD tranny benefiting...

Cheers,

Clarke

its a 6:72:1. i didnt know the A3's had different ratios??

 

[adamsoffroadperformance]

As far as I know rockwell made 2 ratios for the 2.5 axle the 6.72 that most people have and there was another military vehicle that used these axles that had a different ratio but are rare. Talking with Ed at Memphis Equipment awhile back he had mentioned what the vehicle was but didn't know what the ratio was.

 

[m-35tom]

with final drive ratio swap, you affect all gears in trans, with 5th gear swap you don't. makes a huge difference in usefullness to still have off road gears and a more normal od instead of the limited .78 they come with.

tom

 

[adamsoffroadperformance]

I thought thats what low range was for? Hey Tom what size shafts are in those airlocked axles? I have several sets of 5 tons with the same design airlocker but instead of the standard 2 1/8" 16 spline shafts mine has 2 1/4" 23 spline shafts in them. I was just curious if they upgraded the 2.5 ton shafts also.

 

[m-35tom]

they are 1/8" larger with bigger spline.

 

[Stretch44875]

Using a gasser transmission would give you a deeper 1st gear(7.00/1), and closer shifts. Lack of overdrive would bring the rpms back up. Having driven a gasser, they shift nicer and rpms are much better between shifts.

The 4.90 set, with a gasser tranny, would give you 61mph at 2500rpm, approx the same as 11-20 tires.

Seems like a lot of work though to just end up where you started. 11-20 tires would bump the speed up to 65mph at 2500rpm, which I think would be a perfect set up with the better transmission. Too bad it would cost so much to do! For the money, I'd say Tom's set has the most bang for the buck.

Dennis

 

[adamsoffroadperformance]

I definately like Toms setup. And if I start running my deuce alot more I may consider it too. I thought about Gearharts 5.41 ratio gearest and Toms tranny mod. It would be capable of higher speed IF NEEDED, But I would think with both you could cruise at 65mph even more comfortably as long as you don't get below the targeted power range. In that case you would probly burn more fuel because of working the engine too hard.

 

[SixSpeed]

I heard someone mention a 5th gear swap in this thread. Anyone have more information on this? I have always thought that the 5th gear ratio is too close to 4th. I have always said the M35's are one gear short of perfection.

 

[Dieselsmoke]

If you're in such a hurry to get somehwhere in the deuce, then you're not enjoying your truck. Park/sell it and get something else.
Just my opinion, guess the world don't go fast enough for some folks.

 

[tm america]

i have never seen a different ratio from the factory in the 2.5ton rockwells.the a3 doesnt have od but it has 14.5 and a higher reving engine that give it the same top speed as the a2 not a different gear ratio.
the problem with these gear sets 4.90 and 5.41 are the deuce doesnt have enough hp or torque to push that kind of gear.they are so underpowered that when you hit od with those gears it would bog and go slower not faster......i need a gear set that is the other way .something like a 7.20 or so to help out with the 15.5si guess i could go with the 3052 trans and a 4.90 gear set to get me where i need to be but for that cost i might as well get me a cxt or c6500 4x4 and i will have ac and power everything

 

[tm america]

those gears are perfect for guys running 44s and 49s on a mudd truck with big hp he should advertise in the 4x4 mags

 

[SasquatchSanta]

Using a gasser transmission would give you a deeper 1st gear(7.00/1), and closer shifts. Lack of overdrive would bring the rpms back up. Having driven a gasser, they shift nicer and rpms are much better between shifts.

The 4.90 set, with a gasser tranny, would give you 61mph at 2500rpm, approx the same as 11-20 tires.

Seems like a lot of work though to just end up where you started. 11-20 tires would bump the speed up to 65mph at 2500rpm, which I think would be a perfect set up with the better transmission. Too bad it would cost so much to do! For the money, I'd say Tom's set has the most bang for the buck.

Dennis

Interesting numbers Dennis.

Have you ever ran the numbers to see what speeds you would get with a gasser with 9:00 & 11:00 rubber and stock gearing "if" you were to install an overdrive transmission from an M35A2 from a milti deuce?

 

[SasquatchSanta]

I am happy to see that gearsets are made but I can't handle $6600 for one Deuce, maybe we could all contact this guy and he might get cheaper? JT out

Not that I'm trying to take the lead in this but I called Gearhart Engineering @ 269-278-6945 and spoke with Russ.

My main reason for calling was to talk about brakes. He said the disc brakes that are shown on his website were built for an offroad vehicle that was equipped with 15" wheels therefore the rotors are only 12" in dia and not adequate for a road deuce specially one with 53" flywheels for tires (my words, not his). He said he could build deuce on-road brakes but was not too excited about doing so.

He questioned what was wrong with the stock brakes?

Concerning the 5:41 gearing --- he said he could get his prices down if he could build a production run. I got the feeling that he feels a production run would be somethere between 24 & 36 sets (of 3).

 

[trudsmtuner]

Couldn't you just put an overdrive unit on behind the transmission?