4.56

 

Wow. I stand corrected. When I was looking into gear swaps for my CJ that's riding on a 44 front and 9.25 rear end I could have sworn all I could get was 4.56's.. that was a year or so back, but maybe I didn't look very well...

 

true and correct!
+1

 

Bit of a hijack here.
If you came stock with 3:55's at what point do you need a different carrier on the Dana 44 and Corp 9.25?

 

one more vote for 4.56's, never heard of anyone complaining cuz they geared too high, only the guys who didn't go as far wishing they'd done it right the first time.

 

You also have the option of purchasing a GearVendors underdrive unit along with a driveshaft:

http://www.drivetrain.com/overdrive.html

Why go this route?

The advantage is that when you eventually sell your truck
you can take the GearVendors off and either re-use it,
or sell it on eBay for a very good price.
If you save your original driveshaft it can be put back on the truck when it goes up for sale.

On the other hand
when you install 4.56 gears in both differentials
you have
'marked' your truck
as one that
'has had a hard life'
and it will decrease its resale value to knowledgeable buyers...especially dealerships and people looking for a 'reliable' work truck. The money spent on the two differentials will be lost, plus you will suffer another $500 to $1500 in lower resale.

Finding another enthusiast who wants your mods is possible,
but is a doubly hard search to make a sale with,
especially since there are many used pickups on the market right now.

 

I have an appointment for next week to get 4.56 gearing installed by 4wheelparts in Tampa. I wanted the 4.88 gears but they said that they could only get them for the back axle, not the front, and they were on "indefinite" backorder from the factory. They also questioned my decision to go with 4.88 gears and I told them I wanted a little more power than stock performance for my 36.5" tall DC-FCII tires. They said that they wouldn't use 4.88 gears for anything smaller tham 40" tires because they would be geared too low for overall performance on the street (highway). They assured me that I will love the performance from the 4.56's and even tried to get me thinking about the 4.10's, to which I said absoluteley not. I have been thinking about the 4.56 and 4.88's for a little while now. I had made the decision to go with 4.88's until I was informed of the inability to get the front done and the backorder on the rear. I would love to hear how they work from someone who actually has them on their truck with the same size tires. Real world experience beats what looks good on paper...

 

I have the Off-Road package dodge ram, they came with 4.10 gearing ratio correct? What exactly does 4.10's excell in? I run 35" tires, and they seem to lug them around with tons of power still, and I still can hit 100mph quickly (not that i do it often).

 

I've gone to 4.56 from 3.55. Best improvement I've done. I can now use overdrive again. The front carrier will need to get switched out to go from 3.55 to 4.56. 3.92 and up is one carrier and 3.73 and down is another. Runs about $75.
http://www.drivetrainspecialists.com...44/open-1.html

 

4.10's for 35" isn't that bad. If you look at this chart:

http://www.drivetraindirect.com/t_gear_calculator.htm

You'll notice that you're getting just below"best overallperformance" and a little more into the "better fuel economy" range (which issort of ironicbased on your plummeting MPG post). Theoretically, you want to land right in the center of dark green band. 4.56's would be ideal, but is itworth the $1-1.2k to you?

For me going from 3.55 to 4.10 on 30.5" tires was great! I don't slow down on hills anymore, I have what I would consider good usable passing power, and some more jump off the line.Also, (and I can't explainthis logically) theoverhead computersays I'm getting better gas mileage than before the swap, and the wallet agrees. Maybe I've just been babying it a little more as I haven't yet put 500 miles on the new gears yet, but I think the added power gets me up to the speed Iwant quicker using the same amount of throttle, and then I back offthe pedal a bit when I get up to speed. Keep in mind, I live in the Dallas area and a good bit of driving anywhere down here is on the highway. I think my total RPM's at 70MPH have increased from 1900 to about 2150. This should be costing me gas, but I haven't felt it in the pocket book.

Also note that the 30.5 inch tires I'm running is the theoretical height. I measured them last week and at the 35psi mark they are roughly 29.5" not 30.5" so according to that chart I'm kissing the line between power/bad mileage and best overall performance. BUT I LOVE IT! That's why I recommended goingupto 4.88for the 35" tires.

Heck, if you're trying to save gas just keep with the stockers.