Re Gearing to 4.10

[Muncher]

Ok so I am thinking i need to re gear my axles sooner then later. i plan on running 33 inch tires so 4.10 gears seem to be what everyone recommends. i have a rear dana 44 and a front dana 30 could i possibly get some help putting together a list of what ill need to do this? thank you.  

[derf]

1.  Find a good reputable shop.

2.  Drop off Jeep.

3.  Go back, pick up Jeep.

 

Or:

 

1.  Buy a bunch of tools and parts. (Probably more expensive than above)

2.  Watch a ton of videos and learn how to do the meticulous work.

3.  Spend a couple days doing the labor to set up the gears.

[ghetdjc320]

I’d recommend 4.56 gears for 33’s. A touch high for 33’s but they would also work for 35’s. 
 

What gears do you have currently? If 3.73 or below in the rear you will have to do a carrier swap or use thick cut gears (preferred). The Dana 30 carrier break is also 3.73 so any numerically higher gearset will need a new carrier. Now is the time to consider full lockers (arb, Detroit, Eaton, truetrac etc). I get all my gears and install kits from revolution axle and gear. They used to be superior gear and have great products and service. If your going to install the gears yourself you’ll need quite a few specialty tools. This will not be a cheap endeavor unless you can get free/cheap parts and labor 

[ghetdjc320]

4 minutes ago, derf said:

1.  Find a good reputable shop.

2.  Drop off Jeep.

3.  Go back, pick up Jeep.

 

Or:

 

1.  Buy a bunch of tools and parts. (Probably more expensive than above)

2.  Watch a ton of videos and learn how to do the meticulous work.

3.  Spend a couple days doing the labor to set up the gears.

 

Big investment especially if your doing just one set of axles

[Pete M]

I have 4.10s for my 33s and wish I had 4.56.  But it was the deepest factory gears for the Ford axles so I went with it.   

[Muncher]

11 minutes ago, derf said:

1.  Find a good reputable shop.

2.  Drop off Jeep.

3.  Go back, pick up Jeep.

 

Or:

 

1.  Buy a bunch of tools and parts. (Probably more expensive than above)

2.  Watch a ton of videos and learn how to do the meticulous work.

3.  Spend a couple days doing the labor to set up the gears.

I'd definitely have a shop do it but I'm just thinking of buying the parts and having them doing it

[MJCARENA]

My 1989 Wagoneer limited I had 4.56 gears and 33 inch tires and to me that was a great combination.

[Muncher]

8 minutes ago, ghetdjc320 said:

I’d recommend 4.56 gears for 33’s. A touch high for 33’s but they would also work for 35’s. 
 

What gears do you have currently? If 3.73 or below in the rear you will have to do a carrier swap or use thick cut gears (preferred). The Dana 30 carrier break is also 3.73 so any numerically higher gearset will need a new carrier. Now is the time to consider full lockers (arb, Detroit, Eaton, truetrac etc). I get all my gears and install kits from revolution axle and gear. They used to be superior gear and have great products and service. If your going to install the gears yourself you’ll need quite a few specialty tools. This will not be a cheap endeavor unless you can get free/cheap parts and labor 

Yeah I knew it wouldn't be cheap but kinda necessary. My current gear ratio is like 3:02 or something really low like that. Also I think I'd do a locker in the rear just for the time being. 

[ghetdjc320]

26 minutes ago, Muncher said:

Yeah I knew it wouldn't be cheap but kinda necessary. My current gear ratio is like 3:02 or something really low like that. Also I think I'd do a locker in the rear just for the time being. 

Yeah that’s a good idea. You can always add an Aussie locker up front without messing with your gears at all. Have the full carrier locker of your choice installed along with the gears in the rear. 4.56 is a really nice ratio for 33’s as @Pete M pointed out. I have zero complaints with them and would have no issue going to 35’s if I chose to

[derf]

30 minutes ago, Muncher said:

I'd definitely have a shop do it but I'm just thinking of buying the parts and having them doing it

Most shops won't install parts you bring them.  The ones that do are likely to not warranty the work since they can't be guaranteed that your parts are good.

 

Shops will usually give you a good package deal for parts and labor.  And since they warranty the work, they use good parts you can trust.

[derf]

Oh, and I have 4.56 gears with the automatic and 32" tires in my XJ.  It's a good combination.

 

I might do 4.10s with the manual and it would probably be ok.

[ghetdjc320]

@derf Has a magical calculator for gear ratios, tire size, tranny and tcase combo and more on that link in his sig. That is one of the best resources for figuring out what gearing to go with. I’ve been using it for years on my builds. 

[Jesse J]

7 hours ago, derf said:

Oh, and I have 4.56 gears with the automatic and 32" tires in my XJ.  It's a good combination.

 

I might do 4.10s with the manual and it would probably be ok.

I'm thinking of this too. what does your mpg look like?

[Muncher]

I was thinking 410s instead of 456 because my truck does kinda have to be my daily so I thought 410 would be better 

[ghetdjc320]

4 minutes ago, Muncher said:

I was thinking 410s instead of 456 because my truck does kinda have to be my daily so I thought 410 would be better 

 The difference is nice when it comes to crawl ratio and acceleration. It’s been my experience that the 4.0’s like to run mid to high 2k when cruising. With my built engine, 4.56 gears and aw4 I’m still getting close to 20mpg when cruising. 

[derf]

1 hour ago, Jesse J said:

I'm thinking of this too. what does your mpg look like?

It's in the mid to high teens depending on city/highway mix.

[Pete M]

If you're worried about MPGs, don't daily a lifted brick on 33s.   

 

the 4.10s are... tolerable.   Nothing more exciting than that.  I only ran them because my budget didn't allow for a regear.  I still want a bit more oomph to get going from a start. 

[Jesse J]

13 minutes ago, derf said:

It's in the mid to high teens depending on city/highway mix.

aw4 or ax15?

[89 MJ]

9 hours ago, derf said:

Oh, and I have 4.56 gears with the automatic and 32" tires in my XJ.  It's a good combination.

 

7 minutes ago, Jesse J said:

aw4 or ax15?

Looks like he has the AW4.

 

 

If you are looking to daily drive your truck, I would do 4.10s and 31s. If you go much bigger than that, it is harder for all of the chicks to get in your chick magnet.

I'm kidding, don't worry, just one chick for me!

[PIKE]

Another vote for 4.56 with 33s. Highly recommend a trutrac for the front, your choice for the rear. 

[derf]

44 minutes ago, Jesse J said:

aw4 or ax15?

AW4

[gogmorgo]

My plan for my mj has also been 4.10 and 33’s. To match the same ratio as the factory 3.07 and ~29” tires on 33’s you would only need 3.73 gears, which is roughly the same as running 31’s on 3.55 gears, as I’m doing in my manual ZJ. If you need deeper gears offroad, that’s what low-range is for. If I was towing regularly with it I can see wanting more gear, but it’s fine as a daily. It’ll run out of traction before it runs out of torque to climb hills, and a 3000rpm clutch dump launch and WOT acceleration still scares passengers who weren’t expecting it (it hooks hard and then goes) and I have no issues comfortably keeping the revs between 1000 and 2500 rpm under normal driving. It’ll still pull most hills on the highway in cruise in 5th gear without losing speed, and I live in the Rockies, so there’s lots of them and they’re not always gentle.

Keeping the revs down at highway speed also goes a long way for comfort on long drives.

 

But that all said, if you think you ever might go beyond 33’s, going with deeper gears will have you ready for that, and won’t be unmanageable in the interim, and you’ll only need to pay to regear once. It’ll also be helpful if you’re hauling around lots of extra weight in the form of armour or camping gear. 

[89 MJ]

I have towed ~1,500 pounds (estimate) with my MJ with 31s, 4.10s, while running on maybe 5 cylinders. I could still just let the clutch out and it would start moving, no throttle necessary. My dad has a 5.3 YJ on 35s and only has 4.10s in it, but that is comparing apples to oranges. If you are dead set on 33s, I would still just do 4.10s, especially if you want to go on the highway at all.

[Smokeyyank]

I vote 4.56's for 33's especially if you have a auto. The MPG difference aren't t going to be noticeable at all, but general drivability will be. On my old XJ I had a aw4 with 4.10s and 31's that was a great combo. When I moved to 33's it wasn't, the low end was just meh and trying to get up hills you could feel the difference. Granted I'm at elevation with lot's of hills but even when Id drove it around town it was noticeable. 31's 4.10s would be fine 33's go 4.56. 

[JMO413]

I debated this allot lately with my XJ and 4.56 seems like the right answer to me.

 

http://www.grimmjeeper.com/gears.html

 

I would suggest playing with this site. It is really a great tool.