New Gears for Dana 44 Rear Axle - Is this the way to go?

[Jeepedo129]

I'm in the same boat. But, from what I've been able to find out after reading a bunch of different threads, is the gear set up right for you is based on your driving style, what type of off-roading you do - ie, rocks or mud or both. As well as where you live, rigs at Sea level will behave differently depending if they're at sea level or up 5K ft.

Personally, I think you being in Oregon, I think 4:56s might be a little deep for 31s, but if you have any intentions of going bigger it's better to gear once. If you're towing, 4:56s would add a good amount of towing power. I have 32.5ish tires and I'm going to put 4:56s in.

Just my .02

 

[PumpinIron]

I have no intentions of going bigger than 31". I know that no one will believe that but it really is the truth.

This rig is a daily driver, occasional off-roader (light trails, snow, sand, etc., no rock crawling though), and family vehicle mostly.

The elevation here is about 100 feet above sea level on average. There honestly aren't very many hills around here unless you're going up to the mountain or through the mountains to the coast.

80% of my driving is stop-and-go city driving. The other 20% is highway driving. I just don't want too gear is so extreme that when we do take it on the highway for a road trip that it pisses the wife (and everyone else) off because it's cruising at such a high RPM or something.

 

[TRCM]

I have no intentions of going bigger than 31". I know that no one will believe that but it really is the truth.

This rig is a daily driver, occasional off-roader (light trails, snow, sand, etc., no rock crawling though), and family vehicle mostly.

The elevation here is about 100 feet above sea level on average. There honestly aren't very many hills around here unless you're going up to the mountain or through the mountains to the coast.

80% of my driving is stop-and-go city driving. The other 20% is highway driving. I just don't want too gear is so extreme that when we do take it on the highway for a road trip that it pisses the wife (and everyone else) off because it's cruising at such a high RPM or something.

The difference @ highway speeds is ~11%....IE, 4.10 @ 2000 rpm or 2225 rpm w/4.56s

 

[Jeepedo129]

I don't know if you've looked at one of these charts, but it gives a rough idea of where you'll be. This chart assumes 4th gear is 1:1 however, the AW4 4th gear or OD is actually .75:1 so to find your RPM, multiply the listed RPM by .75

If you're going to stay on road mostly and don't crawl, then 4:10s will suit you're needs.

Probably over killed the topic but what's worth doing is worth over doing. right?

 

[PumpinIron]

I don't know if you've looked at one of these charts, but it gives a rough idea of where you'll be. This chart assumes 4th gear is 1:1 however, the AW4 4th gear or OD is actually .75:1 so to find your RPM, multiply the listed RPM by .75

If you're going to stay on road mostly and don't crawl, then 4:10s will suit you're needs.

Probably over killed the topic but what's worth doing is worth over doing. right?

I have read numerous charts like that and all of them seem to put me at about a 4.10. I don't do hardly any crawling at all which is another reason that the 4.56 seems like overkill.

On top of that I don't have any huge heavy bumpers, roof racks, spares, etc. It's basically just stock with a nice lift, soon to be D44 rear end, a locker, and some performance mods.

I didn't realize the AW4 had a .75:1 ratio, thanks for pointing that out to me since it definitely makes a difference!

 

[Jeepedo129]

I didn't realize the AW4 had a .75:1 ratio, thanks for pointing that out to me since it definitely makes a difference!

Yep, just some food for thought

 

[PumpinIron]

Yeah, so according to that char I would be at 2172 RPM at 65 mph with 4.10 gears on the AW4 tranny.

That is of course doing the given RPM multiplied by .75.

If that's the case that's not bad at all, that's actually awesome.

 

[Jeepedo129]

As others have said, there's only a 200rpm difference between 4:56 and 4:10s.

All this thinking has made me think of going deeper in my gear selection.... Haha

 

[PumpinIron]

Yeah with only 200 rpm difference I am rethinking it now too. I wonder what (if any) the loss in mpg would be with 4.56 as oppose to 4.10.

 

[markw]

If you're concerned about mpg, Toyota makes the Prius. I just saw 16mpg on the swamp lake tripe, 400 miles one way, some of that sitting in LA traffic. 285/70-17 which measure out to just a tick under 33". The gear charts don't account for the weight you're carrying, they are just simple rpm vs road speed for tire/gear ratio. I'm right at 2500 rpm for 70 and about 2200 for 65. I can tell you with cooler, camping gear and just me in the rig on the one big climb into the Sierra Nevada's on 168, I dropped it back to 3rd and let it spin, and I was having a hard time maintaining 60mph. If you live in Portland and want to use the jeep to go to the mountains camping, I'd run 4.56's over the 4.10's. Anyone who lives in the mountains will tell you this, flatlanders don't see these issues.

 

[Hypoid]

Yeah with only 200 rpm difference I am rethinking it now too. I wonder what (if any) the loss in mpg would be with 4.56 as oppose to 4.10.

Mount a vacuum gauge in your dash, hook it to manifold vacuum. When the vacuum drops, so does the fuel economy.

My engine cruises best at 2250 RPM, although, I'm not afraid to wind it up on a hill. In a lower gear, it takes less gas pedal to maintain speed, once I start up the mountains.

 

[Jeepedo129]

Yeah with only 200 rpm difference I am rethinking it now too. I wonder what (if any) the loss in mpg would be with 4.56 as oppose to 4.10.

I doubt it would be a noticable difference.