Rockwell axle ratios

[AMX]

Any one here running 4.90:1 ratio gears instead of the 6.72:1? How did it affect the driving (acceleration,cruising speed etc..)? Thanks

 

[tm america]

Not gonna happen with a stock duece.. acceleration would be 0 ... drivng speed in high would be 0.. a multi fuel doesn't have enough power to pull that kind of gear .. Those gears were made for light weight 4x4 trucks with big motors ..Not for 14000 lb 140hp 6x6sNot to mention the 3600 bucks needed for parts to do 3 axles.....

 

[AMX]

If the duece cant handle the 4.90, how does it handle 52" tall tires? They seem to increase the top speed by effectively raising the ratio. Not trying to argue, just trying to understand. I was actually expecting only a bobbed duece would be changed to the 4.90 for daily or often use.

 

[Novice1]

There's no difference between adding taller tires or numerically lower gear rations. The 4.90:1 is equal to a 0.73 overdrive when compared to to the 6.72:1. Most OEM OD's are in the 0.73 to 0.76 range. I think the original tires (9.00 x 20) are 39" in diameter that would mean a 52" tire would equal a 0.75 OD.

The Gross Vehicle Weight of the 4.90 is something you should investigate throughly.

It does seem the tires would be the cheaper way to go.

 

[Novice1]

There's no difference between adding taller tires or numerically lower gear rations. The 4.90:1 is equal to a 0.73 overdrive when compared to to the 6.72:1. Most OEM OD's are in the 0.73 to 0.76 range. I think the original tires (9.00 x 20) are 39" in diameter that would mean a 52" tire would equal a 0.75 OD.

The Gross Vehicle Weight of the 4.90 is something you should investigate throughly.

It does seem the tires would be the cheaper way to go.

 

[gimpyrobb]

Yawn, AGAIN! No there is no way to get 53" tires on a stock deuce. No, nobody that owns a deuce will put that kind of money in their deuce(for those gears). No need to ask about it.


Try reading more.

 

[tm america]

The stock od ratio in a duece is .79 and the have a hard time with that. But you're not just talking about changing the od you are talking about all the gears ... i have 15.5s on my truck and couldn't imagine how slow it would be with 16.00s.. There are several ways to get the same ratio. but it makes a huge difference how you do it . Not enough rear end ratio and to much trans ratio will cause you to kill u joints and transmissions. To much rear end gear and not enough trans gear will break axles .. Not to mention i haven't heard of anyone with a stock deuce being able to pull 6 16.00s. even 4 16.00s and you can pretty much forget about using od unless you're going down a big hill.

 

[AMX]

Yawn, AGAIN! No there is no way to get 53" tires on a stock deuce. No, nobody that owns a deuce will put that kind of money in their deuce(for those gears). No need to ask about it.


Try reading more.

Thanks

 

[oddshot]

You win the S/A response award. I can understand why others would leave the hobby if this is the kind of welcome they receive. And I spend as many hours a day as possible reading these forums, it is a lot of information that combines some fact with LOTS of personal opinion. When you are new to a hobby it is difficult to acquire and digest all the available info.

Welcome aboard young fella ... good to have you here.

There is NO way that you could have known ... but you asked a question that gets asked a LOT around here.

Some folks just can't understand why your Mama didn't pass on all the information concerning the M35 Deuce through her umbilical chord before the moment of your birth.

Just let it go ... or you'll be labeled a "whiney nube" here and on other Deuce sites as well.

anyoldways, the best thing to do if you feel another question coming on is to follow a simple 4 step process before you ask that question.

1. READ THE MANUALS. TM's have a wealth of knowledge ... you can down load them for free at places like, but not limited to: JATONKAM35s HOME ON THE WEB

2. DO A SEARCH. Think of this place as a HUGE LIBRARY, which it is. Run a through search on this forum ... and the Deuce forum as well. You will find TONS of info on axle ratios.

3. Although its not exactly relative to information per se ... go back and read the RULES of this forum. Folks here are REAL touchy about the rules.

4. Cleanse yourself of all earthly impurity of thought, word or deed. Assume a lotus position. Begin by chanting your mantra or by intoning the Hara Krishna, and continue until you have become ONE with the universe and ALL knowledge.

If, after following ALL of those 4 steps you do not have the answer to your question ... THEN and only then ... should you consider bringing your question here, before the all knowing and all seeing.


Otherwise ... just blurt it on out ... one of us other whiney nube's will be happy to try to help you out.

oddshot

 

[AMX]

Thanks for the replies.

 

[tm america]

amx lighten up..They just aren't intended for a 6x6 duece..Do a google search you'll find more info on who is using them . If you have a duece and want less gear ratio bigger tires is the cheapest way to go .If you want a higher top speed and nothing else to change m35tom makes a improved od gear set for the trans thats a third of the price of doing gears in three diffs. Plus he fixes some of the other problems with the stock deuce trans in his kit

 

[m-35tom]

There's no difference between adding taller tires or numerically lower gear rations. The 4.90:1 is equal to a 0.73 overdrive when compared to to the 6.72:1. Most OEM OD's are in the 0.73 to 0.76 range. I think the original tires (9.00 x 20) are 39" in diameter that would mean a 52" tire would equal a 0.75 OD.

The Gross Vehicle Weight of the 4.90 is something you should investigate throughly.

It does seem the tires would be the cheaper way to go.

but that would be in 4th gear, not 5th. stock 5th would then be final ratio of 3.82, while my od gears give 4.63 final ratio which is all the multifuel will do. how much do 4 tires and wheels cost? compared with $1334 i think my way may be cheaper.

tom

 

[kc5mzd]

Either way you go it will be expensive. Both are worth looking into. With the axle ratio change you will run in 4th close to what you are in 5th now. Keeping the smaller tires will help prevent excessive steering resistance. But once you comit there is little you can do to fine tune the top speed to power ratio. When you change the tire size you will have a harder time steering and will not be able to turn as sharp, But you can find a lot of surpluss tires in diffrent sizes and keep swaqping them out till you find a ballance that makes it easier to drive in your area. There is a big diffrence between running a m35a2 in a hilly region and in a flat area. I have found the 11R20 tires with all stock gears to be the best trade off where I live.

 

[AMX]

Either way you go it will be expensive. Both are worth looking into. With the axle ratio change you will run in 4th close to what you are in 5th now. Keeping the smaller tires will help prevent excessive steering resistance. But once you comit there is little you can do to fine tune the top speed to power ratio. When you change the tire size you will have a harder time steering and will not be able to turn as sharp, But you can find a lot of surpluss tires in diffrent sizes and keep swaqping them out till you find a ballance that makes it easier to drive in your area. There is a big diffrence between running a m35a2 in a hilly region and in a flat area. I have found the 11R20 tires with all stock gears to be the best trade off where I live.

Good thought, I live IN the Smoky mountains (On a mountain).

 

[kc5mzd]

You could remove the rear tandem driveshaft and the front driveshaft so only the driveshaft that goes from the transfercase to the front rear axle is hooked up, then swap only the tires on the front tandem and see how your truck deals with the hills. With small tires on the rear tandem you might get a set of 52"s to fit just to see how the truck would run. Just be carefull and remember that when you finaly decide and go back to matching tires hooking up the driveshafts will also slow you down a bit.

 

[tm america]

amx do you have a deuce yet?

 

[AMX]

amx do you have a deuce yet?

No, I have been researching. I probably need to sell my SR25 rifle (M110) to fund the purchase, or maybe just trade it to one. I have decided that I do not want a 5 ton (too big), but am uncertain about an A3 vs. an A2. I think an A2 might be fine with PS.

 

[tm america]

The reason i ask is you really need to drive one to know what we are talking about .. numbers and research does quite sum up what a five minute test drive on a hilly road could do instantly.. i think most 4 cyl engines in cars have similar hp to a stock deuce but are 10000lbs lighter.Then think how the car would pull with 40 inch tires pulling a 10000lb trailer?....All i can say is drive one and look at what people are doing before getting your hopes up about 4.90 gears

 

[AMX]

The reason i ask is you really need to drive one to know what we are talking about .. numbers and research does quite sum up what a five minute test drive on a hilly road could do instantly.. i think most 4 cyl engines in cars have similar hp to a stock deuce but are 10000lbs lighter.Then think how the car would pull with 40 inch tires pulling a 10000lb trailer?....All i can say is drive one and look at what people are doing before getting your hopes up about 4.90 gears

But they do not have the torque or gear multiplication. I Would like to drive one, but have not seen one of interest for sale around here. I do not expect them to be quick or comfortable, I just want one. I have decided it is time in my life to get some of the things I want instead of holding on to everything I buy forever. I have had my AMX for over 30 years now. I have been wanting a military truck for over ten years, it is just time.

 

[kc5mzd]

They only have the gear ratio and torque advantage if you leave them stock. New gears and or taller tires uses up the torque fast.
Keep at it and keep an eye out for a rally in your area. I think a close up at a rally would be the best thing for you. You might find someone that will let you drive one. If not I bet you would at least get to ride in one.