4.10s in a 2006 3.7L

[cplchris]

I'm looking to regear and I've heard a few different things when it comes to doing so.

my jeep is a 2006 with the 3.7 v6 and 3.73 gears front and rear.

the dealership says that the front carrier wont work with 4.10s due to the gears being thicker so they won't fit. and from this thread i found over on lost that is correct, LOST JEEPS • View topic - ? on 4.10 gears in the front

i have also heard that just swapping the front ring and pinion with a 4.10 set from dana spicer will work no problem.

my question is what is true what is myth? do i need to find a carrier from a 4 cylinder liberty and swap that or will the dana 4.10s work with the carrier i currently have?

 

[Gyro]

I just did a regear to 4.10's on my 07.Bolted right up.
As far as I know dana spicer are the only option for the front.
The front is a D30a/super 30,D30 gears won't fit.

Your 06 rear diff may have M10 ring gear bolts,earlier models have 3/8 bolts.
The ring gear from earlier models will fit you just need the metric bolts.

Good luck

Gyro

 

[JeepCoMJ]

What you're asking is specifically geared towards the carrier in the axle.

The answer is yes, you need a new carrier to install in your differential.

But you don't need to find one from a 4 cylinder liberty. You can buy a brand new carrier for a decent price. If you're putting new gears in your axle housing, you're going to need carrier bearings, pinion bearings, shims, seals. It is not something a novice has the skill to do. In fact, I'm fairly skilled at doing many different things on jeeps, and I have done gears, but it is not my strong suit. It takes me 10x as long as it would take a pro.


The rear (chrysler 8.25) has a carrier that's compatible with 4.10's. But again, it's going to require new bearings and seals and shims (i.e. a master install kit).

 

[tjkj2002]

No different carrier needed to switch from 3.73's to 4.10's in the D30A,the break for a D30 is 3.54 down and 3.73 up.


Oh and no shims at all required or even used in the 8.25 though you do need a special tool(or make one) to set the pre-load on the carrier bearings.

 

[JeepCoMJ]

Thanks. both dana 30 and dana 30a are 3.73 and up. My bad, I was thinking of Dana 44's. been toying with those more lately than anything else.


But chrysler 8.25's DO have shims, and having them set right plays a big part in getting the pinion set to the proper depth, with the proper preload, and good backlash.

 

[cplchris]

thanks for all of the help guys, ill be picking the front gears up from tommudd soon and then ill save up and get the rears and rebuild kits and in a few months ill be getting more than 10 mpg finally lol

 

[cplchris]

bringing this back from the dead, i am trying to find the part number for the 4.10 ring and pinion set from dana-spicer. i looked at the catalog and it has the kj model years starting with 2000-01 through 2005 (2006 is skipped) and picked up with 2007 (i suspect they may be using the date of manufacture instead) from what i saw though the 2005 ring and pinion set is part number 84006-5. can anyone confirm that that is what i need without any doubt before i start buying parts? my kj is a 2006 sport 4x4 3.7

 

[wheeee32]

How much are you getting the R & P for? The best I've seen is $300 new.

 

[cplchris]

300 seems like the average price...they can be found cheaper but then you would be taking the risk of dealing with a website you've never heard of so not worth the risk to save 20 bucks. idk what i'll be paying until i know what i need, i will have to call dana-spicer tech support today and hopefully get that figured out. people on here have been helpful but i keep reading/hearing different stories about the 2006 so i don't want to end up tearing into the front axle only to find out the parts won't fit. if i have to buy a new carrier i'll probably do a DTT front and rear.

 

[cplchris]

ok so i found this thread on lost and it seems that the part number i have is correct for the dana gears (part number 84006-5) time to get ordering.

LOST JEEPS • View topic - D30a 4.10 Gears

 

[cplchris]

bumping this thread again, i have read that there are shortcuts for pulling the front axle to do the swap, would anyone care to share the shortcuts with me? im getting ready to order parts in the next month so i want to see what i'm getting myself into here. i will be doing this work in a well equipped shop with the help/guidance of a very good mechanic.

 

[tommudd]

This is the way i do it, others will more than likely have their way / shortcuts
Pull front suspension
( same as doing a lift basically)
Pull CVs out
Remove front driveshaft
Loosen steering rack, remove the two bolts
Loosen the two front mounting bolts for the front diff
The way they are installed you can not remove completely due to the LCAs
Run the nuts out and cut the bolt off
Unbolt the two rear mounts
Drop the diff down out
Get two new bolts for the front mounts and reinstall them opposite from the way the factory did
Install everything you removed

I think thats about it, when I get under one I just go on automatic pilot and never think what has to be removed , just do it :shrug::icon_lol::icon_lol:

 

[cplchris]

thanks for all the help tom. once i get all this figured out and done i plan on creating a thread on how to re-gear (not going to include the installation of the gears) i will list all part numbers, required tools, and how to pull the front axle out of the jeep.

here is my shopping list so far (everything will be purchased from JBA to support an awesome company and keep it simple for future liberty owners):


(JEEPIN BY AL SKU - PRODUCT LINK)

D30KJ-410LIB-OE - Nirto Grear 4.10 Ring and Pinion
YK D30-SUP - Yukon Bearing & Seal Kit
C8.25-410-NG - Rear Diff Ring and Pinion 4.10
MKC 8.25-B - KJ - Master install Ring and Pinion rear diff.

that should be everything for a basic regear correct?

i am also going to be putting a true trac in the rear axle

EAT912A553 - Chrysler 8.25 TrueTrac by Eaton

aside from the unit itself is there anything else i need in the way of an installation kit that isn't listed above?

Troy also mentioned needing a specialty tool to set the preload on the carrier bearings, i am guessing this is it?:

YT YH-01: Yoke holder tool

 

[CzarKJ]

thanks for all the help tom. once i get all this figured out and done i plan on creating a thread on how to re-gear (not going to include the installation of the gears) i will list all part numbers, required tools, and how to pull the front axle out of the jeep.

here is my shopping list so far (everything will be purchased from JBA to support an awesome company and keep it simple for future liberty owners):


(JEEPIN BY AL SKU - PRODUCT LINK)

D30KJ-410LIB-OE - Nirto Grear 4.10 Ring and Pinion
YK D30-SUP - Yukon Bearing & Seal Kit
C8.25-410-NG - Rear Diff Ring and Pinion 4.10
MKC 8.25-B - KJ - Master install Ring and Pinion rear diff.

that should be everything for a basic regear correct?

i am also going to be putting a true trac in the rear axle

EAT912A553 - Chrysler 8.25 TrueTrac by Eaton

aside from the unit itself is there anything else i need in the way of an installation kit that isn't listed above?

Troy also mentioned needing a specialty tool to set the preload on the carrier bearings, i am guessing this is it?:

YT YH-01: Yoke holder tool

Just a heads up this is the cheapest one I have found so far.
http://www.summitracing.com/parts/dtl-912a553

 

[cplchris]

Ok so I have almost all of the parts I need, the overhaul kit for the front and new front housing will be here tomorrow.

I looked through the fsm and it seems I need to get a specialty tool to set pinion depth and a couple other specialty drivers and pullers for the axle seals and bearings (it looks like they are recessed and cannot be done with regular drivers.

Do I need these tools or is it doable without them?

 

[4x4kayak2112]

Yes you need the tools, thats why we charge a pretty penny to install and repair diffs

 

[sota]

part of the reason when/if I decide to do 4.10's i'll be looking for a 4-****** donor vehicle. hell I can always use the other spare parts as well, or part it out.

 

[tommudd]

Ok so I have almost all of the parts I need, the overhaul kit for the front and new front housing will be here tomorrow.

I looked through the fsm and it seems I need to get a specialty tool to set pinion depth and a couple other specialty drivers and pullers for the axle seals and bearings (it looks like they are recessed and cannot be done with regular drivers.

Do I need these tools or is it doable without them?

Just because you have the tools doesn't make it easier. Setting up diffs is not something you just buy the tools and do it. There are tricks to setting them up properly. I used to be able to do 9 inch and 44s in my sleep almost but got out of doing them and wouldn't even attempt to do one now . ( worked in Ford Dealership doing all diffs and C4/ C6 rebuilds at the time) Thats why I bought the parts and had a Jeep tech do my rear diff on the side , he did it all the time and had it up and running in no time.

Just my opinion:shrug::icon_lol:

 

[wheeee32]

What does a KJ feel like with 4:10's? It keeps getting dangled in front of me then taken away.:happy175::icon_lol:

 

[TwoBobsKJ]

What does a KJ feel like with 4:10's? It keeps getting dangled in front of me then taken away.:happy175::icon_lol:

It feels like a new vehicle - especially if you've been running oversized tires with the 3.73's.

I've recently put 265/70's on mine and it still pulls nicely up hills on the highway - no downshifting when running cruise control at 70mph. Gas mileage has dropped recently but I blame that on crappy winter fuel - my wife's '14 Ford Fusion has lost a couple miles to the gallon too.

You'll love 4.10's :waytogo:

Bob