Gear ratios

[Polarcub]

Nick I run 4.88s and love them in the dirt. Sand is no problem and you can run the freeway comfortably at 70+. I think this is a great ratio for a driver/toy. I think you would be better off saving for the 4.88s 4.56 will put you about stock with 35s 4.88s with 37s put you about stock. If you make it to the race in May take mine for a spin in the sand wash to get afeel for them.

[Agilt]

Tried search but didn't come up with anything.

What do ya'll feel is a good gear for a multiuse truck with 35's and the E4OD?

4.56 or 4.88?

[bajascott]

its a toss up, i was going with 4:88's on mine.

[Nick]

I went back and forth on this, and i decided on 4:56's.

[Polarcub]

I wresteled with this for a long time...I decided on 4.88's and do not regret it in the least. I can run donw the freeway at 7- at about 2900 rpms and in the dirt they are great. Off the line acceleration on the street even with a tired motor is very good as well. When I hook up my little trailer even loaded down I have no issues with towing. If I had to say there is a downside it is with towing when you need to drop overdrive your rpms spike pretty quick and I really dont like that part but the duration is relatively short out of overdrive 65 is like 3300 or so on the tach. With the gears and 4 low I have oodles of power.
If it were me I would go withthe 4.88s.

[tcm glx]

I did 4.10s. More because I found a front pumkin geared already. I like it, it runs great on the freeway. On the dirt, I am sure it would be nice to have the 4.56 or 4.88s. I have seen PolarCubs on the street and can attest it has pickup off the line on the street.

[BajaF250]

I went with 4.56s on mine... It really depends on what you want. I really like the 4.56 with my setup, good highways manners, it gives me all I need in the dirt (and I'm guessing the truck is a little heavier than most Broncos). But, if you're looking for that extra punch off the line and throttle response in the dirt, you may be happier with the 4.88s.

[ChaseTruck754]

Discussed this with Culhane last week when I gave him my c6. My c6 and gearvendors combo will be about the same as the E4OD and I think I decided 4.56's - although I can't say for sure as they aren't in yet... 4.71 anyone???

[Prerunbronc]

I have 4.56 with 35s e4od/5.8 and wish I would have gone 4.88

[hobbyturnedobsession]

I've got 4.10's and it does alright. good highway speeds. 70 mph @ 2400 rpm, pulls a loaded down trailer well too. I would go to 4.56's though.

[Phoenix0783]

I put in 4.56s and I like them. Mine is my daily driver, if it wasn't I probably would have gone with 4.88s.

[shockseals.com]

4.56 e4od perfect combo for me. It doesnt hunt between gears and prerunning in D works great. I have yet to drop it into 2nd or 1st gear while prerunning or trail running.

It already gets bad enough gas mileage...I wouldnt want to make it worse going to 4.88s would be my take.

[PaulW]

I run 4.56/35s and I see 1500 rpms a lot while driving easy. So I wonder if one had a non stock motor whth a bunch of Hp then 4.56 would probably to long of a gear and I suspect that the E4od would be in third to have any pulling power at all even when loafing along. Anybody comment on what I said?
Paul

[Polarcub]

Paul, In my limited knowledge and even less real world experince I have to agree with you but I think that with a non stock or near stock motor and the e4OD a dyno would help determine that. I would think a strong lower end would be the key.

[sydude]

I would go with 4.88's. I have an E4OD as well, and I went with 4.88's and I'm very happy with that choice, it's a very good compromise between performance and regular driving.

[kahuna bill]

i've been running 4.56 w/ 35" km2 on a 5.8 l and e4od package, daily driver. millage is about 12 mpg on highways at 65 doing 2200 rpms. can't peel out on the street but i still feel the truck is plenty fast off the line. again, that's just for my daily driver but it still does most things off road that i ask of it.
i'm happy with my 4.56, just wish i would have put a locker in the rear.

[denhabr]

I went with 4.56 gears on my '96 Utah Broncospeed with a 5.0 and E4OD...

Seems just fine with the 4.56 ratio (I used one of those RPM vs. Gear Ratio charts, and it told me I needed 4.56s...and I never looked back...)

http://jeephorizons.com/tech/rpmchart.htmlt

P.S.: I have an open front D44 and a Detroit (Eaton) Truetrac in the 8.8"

[johncharlesb]

I run 4.56/35s and I see 1500 rpms a lot while driving easy. So I wonder if one had a non stock motor whth a bunch of Hp then 4.56 would probably to long of a gear and I suspect that the E4od would be in third to have any pulling power at all even when loafing along. Anybody comment on what I said?
Paul

Definitely agree that built motors usually need more gear. The exception may be the stroker, where you can make bigger hp numbers down low where you use it. (There are other ways to make killer torque down low too like supercharging and N20, but these don't typically apply to our genre.) The gears, convertor, and cam are kind of a package deal.

Sticks are going to need more gear too without the torque multiplication of the convertor.

[mesquito_creek]

Sticks are going to need more gear too without the torque multiplication of the convertor.

Can you clarify this and explain "torgue multiplication"? So does a 5 spd m5od need a lower gear (488) or higher gear (456) versus and auto?

If I understand it correctly based on the gear ratio a manual should be turning higher rpms on 456 than a auto on 488s in 1st and overdrive....

M5OD-R2 3.91 2.24 1.49 1.00 0.80

E4OD 2.71 1.54 1.00 0.71

[campbbg]

I might be wrong but if I understand it correctly the torque convertor will multiply the torque of the engine somewhere between 2:1 - 3:1 which will actually effectively make first gear that much deeper. Also you hopefully will not have the clutch slipping while in gear therefore lowering the rpms versus an automatic. Typically if you have a manual transmission people choose to go one ratio lower (numerically higher) in order to achieve the same results.