Parts for a 4.10 regear

[KJordan333]

Hi,
I'm new to this forum, and I hope I'm not asking something that's been asked way too many times before, but I was looking for some help finding parts for a regear. I have an '05 KJ with the 3.7 and it's currently geared to 3.53 (stock). I'm in the process of getting parts for a regear to 4.10's and want to make sure I'm not missing anything. I have a promotion through Amazon.com and I'm trying to buy the gears off of that website, but I want to make sure that I have the right parts and that they're made by a good brand.

I've been told that I need:
-4.10 ring and pinion for the rear
-4.10 ring and pinion for the front
-2 overhaul kits (is this optional? because only half the shops I visited told me to buy these)
-new front carrier to accommodate 4.10's

What brands would you recommend and not recommend for any of these parts, because Amazon.com only sells a Precision Gear set, and I haven't heard anything about this brand, good or bad.
I hear Yukon makes a good set for the rear and I think they sell the carrier too. The Chrysler 8.25 can only be bought from Dana Spicer, is that correct?

Can anyone give me exact part numbers for all of the necessary parts for this regear, and confirm that the parts I'm looking at would work and be of quality?

Here are the links to the parts I'm looking to purchase from Amazon.com:
Carrier:
Yukon YCD706008 Differential Carrier Case for Dana 30 Axle : Amazon.com : Automotive

R&P:
Precision Gear (30D/410) 4.10 Ratio Ring and Pinion for Dana 30 : Amazon.com : Automotive

Are these good quality/should I buy them? What other parts do I need and from what manufacturers and part numbers?

Sorry if this is a repeat, and sorry there's so much information, I just want to have everything right before I make a purchase.
Thanks in advance for any help.

 

[Luke]

Ask away ... and Welcome!

I'm afraid I'm just a spectator on this topic though.

The Rev. will surely be along soon, he has Yukon's I believe.

 

[tjkj2002]

Only one company makes gear sets for the KJ's D30A and that is Dana/Spicer so you are looking at the wrong gears.JBA is the place to get the correct D30A front gears.As far as the rear 8.25 OE 4.10's or Yukon 4.10's are the best but precision gears are good.And yes get master install kits for the front and rear,make sure the master install kits come with new ring gear bolts and get new axle seals also front and rear(not part of master install kits) as it will be all apart might as well change them.


If you have the 6 speed manual KJ then you do have 3.55 gears and a new carrier is required for the D30A but no new carrier is needed for the 8.25a s there is no carrier break for the 8.25.If you have the 5 speed manual(3.7 V6 only) KJ or any auto trans KJ you have 3.73's and then no carrier needed for the D30A.

 

[KJordan333]

I do have the 6-speed manual so I will need the new carrier and I believe my earlier link is for the "super" dana 30. I was also told to get USA standard gears for the rear and of course yukon in the front. When I search for front gears should I be looking for just dana 30 or dana 30a/dana 30HD? Also, what would the overhaul kit part numbers be? Finally, I've been quoted 1600... does that sound right?

 

[tommudd]

I do have the 6-speed manual so I will need the new carrier and I believe my earlier link is for the "super" dana 30. I was also told to get USA standard gears for the rear and of course yukon in the front. When I search for front gears should I be looking for just dana 30 or dana 30a/dana 30HD? Also, what would the overhaul kit part numbers be? Finally, I've been quoted 1600... does that sound right?

Whoever told ya to get Yukon for the front and USA standard for the rear ???
They really don't know much about what goes in a KJ do they?

 

[Cardhu]

A dana 30A is indeed far from "super" in any way, shape, or form. All the info you need has been listed.

super 30, or regular D30 of anysort other then the dana spicer 4.10 for a dana 30A will not fit at all.

The only thing that might fit 30A from a 30 is diff cover, and even that doesn't have the drain hole we need. Dana 30A only parts.

http://jeepinbyal.com/jeep-liberty-kj/front-drive-axle-components/dana-30a-bearing-seal-kit.html

http://jeepinbyal.com/jeep-liberty-kj/front-drive-axle-components/ring-and-pinion-4-10.html

 

[KJordan333]

Sorry I have so little knowledge about this...

Cardhu, I would need that bearing and seal kit and then those 4.10's are for the front as well? where do I get the rear parts?

Can I just trust a shop to get the right parts?

 

[tommudd]

Sorry I have so little knowledge about this...

Cardhu, I would need that bearing and seal kit and then those 4.10's are for the front as well? where do I get the rear parts?

Can I just trust a shop to get the right parts?

Please reread what tjkj wrote
everything is right there
and some shops you can trust others don't have a clue as to what a KJ needs when it comes to gears

 

[u2slow]

I'm still running 3.55 in mine.... can't find a reason to re-gear yet.:wtf2:

 

[NineFingerFury]

I'm still running 3.55 in mine.... can't find a reason to re-gear yet.:wtf2:

Im interested to know why it'd be worth it for our Jeeps. What's the gain in terms of torque, hp or MPG?

 

[u2slow]

Im interested to know why it'd be worth it for our Jeeps. What's the gain in terms of torque, hp or MPG?

It makes a significant difference on automatics (so I hear) because it affects the shift points and overall transmission life. Even more important for towing. When you shift your own gears with a manual, the point is moot.

I'm getting the best economy driving under 2500rpm. The more miles I can cover at that rpm the better. Besides, the 6 speed has a 'short' OD gear as already mentioned above.

I would re-bearing a used 4.10 diff before I would ever buy new hard parts for the D30a. One plus side is that any D30a carrier or locker can be recycled into the JBA steel diff or a D30 solid axle at a later date.

 

[tommudd]

I'm still running 3.55 in mine.... can't find a reason to re-gear yet.:wtf2:

Well if you did it you'd find out how much better it would run.
Another member on LOST had a 6 speed thought it done OK until he went 4.10s , he said he never knew it could pull hills like that or get the mileage he got after he went to 4.10s

 

[tommudd]

Im interested to know why it'd be worth it for our Jeeps. What's the gain in terms of torque, hp or MPG?

Take a look at what mine has on it, what it weighs, height, tires etc . Now think mine gets 22 - 23 on the highway, 17-18 around town and I don't cut it any slack, it bounces off the rev limiter at least once a day . 192,000 miles and no issues.
Before I regeared with 32 inch tires it sucked gas at 15-16 highway, ran hotter, shifted 17 times a mile and that was on level ground.

 

[tjkj2002]

I'm still running 3.55 in mine.... can't find a reason to re-gear yet.:wtf2:

Come up to 6200' and you will see why.When you can't even use 5th or 6th gear on the highway you'll be begging for gears.

Im interested to know why it'd be worth it for our Jeeps. What's the gain in terms of torque, hp or MPG?

When lifting the goal is to add larger tires then stock.This changes the final drive ratio messing up the trans shift points(since it's all electronic now) and creates more heat load for the engine and trans not to mention lower mpg's.Re-gearing brings you back to that stock final drive ratio as you will gain back your power,less heat load,and recover some of the lost mpg's.Now on a KJ your limited to how low you can go with the stock D30A,for me who has scraped the stock axles and geared much lower then needed(but not low enough for 6200') since my Jeep sees more city driving and low speed offroad then highway.

 

[u2slow]

Come up to 6200' and you will see why.When you can't even use 5th or 6th gear on the highway you'll be begging for gears.

We're definitely at opposite ends of the spectrum. I'm on the coast, on an island, where there is only 1 mile of road I can drive over 50mph. No traffic lights here. When I leave the island and hit the highway, I'm glad I can sip fuel at 2500rpm in 6th knocking down 75mph. :smoke2:

Well if you did it you'd find out how much better it would run.
Another member on LOST had a 6 speed thought it done OK until he went 4.10s , he said he never knew it could pull hills like that or get the mileage he got after he went to 4.10s

How long it would take to recover the cost of a gear swap in fuel savings? No doubt it would have more power, but I would argue driving style is the major factor on economy.

I'm happy to shift into a lower gear - I've got 6 to choose from, and I never used 1st until I put on the taller tires. Towing would be a good reason for 4.10's, but then I've got an older cummins pickup for that job. :icon_wink:

 

[tjkj2002]

We're definitely at opposite ends of the spectrum. I'm on the coast, on an island, where there is only 1 mile of road I can drive over 50mph. No traffic lights here. When I leave the island and hit the highway, I'm glad I can sip fuel at 2500rpm in 6th knocking down 75mph. :smoke2:

Funny thing is my OD is actually higher then your 6th gear.

How long it would take to recover the cost of a gear swap in fuel savings? No doubt it would have more power, but I would argue driving style is the major factor on economy.

I'm happy to shift into a lower gear - I've got 6 to choose from, and I never used 1st until I put on the taller tires. Towing would be a good reason for 4.10's, but then I've got an older cummins pickup for that job. :icon_wink:

Not Tom but I re-couped my cost(not including the ARB/DTT) in less then a year.I gained 6mpg's city and over 8mpg's on the highway and at the time I made a lot of trips from WA to SD.

 

[u2slow]

Not Tom but I re-couped my cost(not including the ARB/DTT) in less then a year.I gained 6mpg's city and over 8mpg's on the highway and at the time I made a lot of trips from WA to SD.

You have an auto? The OP has 6spd....

 

[tjkj2002]

You have an auto? The OP has 6spd....

KJ's 6 speed manual( NSG370 close ratio) = 0.84:1 6th gear
45RFE's = 0.75:1 4th gear

 

[u2slow]

I'm saying with a 6spd and bigger tires, there's likely no need to do anything except alter your driving style slightly.

You're suggesting a gear swap and transmission swap?

 

[tommudd]

I'm saying with a 6spd and bigger tires, there's likely no need to do anything except alter your driving style slightly.

You're suggesting a gear swap and transmission swap?

Gear swap
not sure why folks with manuals think they won't gain anything going to lower gears