Dana 30a fitment

JRB

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I have a new to me 2007 liberty, when I went to change the front diff oil I discovered both diff bearing caps were cracked. I don't know what magic potion that used car dealer put in, because it had very very minimal whine, or no whine at times.

Started looking at gears and parts, one thing led to another, ended up looking for complete diff housings all ready to go.

My jeeps a 6-speed and through searches and the tag on my front end I have 3:55 gears in it, and I was able to find a brand new 30a that was geared 3:55. When I went to cross check if it fit my vehicle, it said only fitment was a 2005 4 cyl diesel. Reading on the forums I was under the impression those received the 4:10 ratio in them, that the housings were the same and the axles varied.

Part numbers were 5135252AA (mopar parts says does not fit 2007 gas) part discontinued, replaced with 5135252AB which does fit.

Really appreciate any help, already ******* by used car dealer, trying to figure how to fix it and not sell.
 

tommudd

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Yes all 4 cylinder gassers were 4.10
Yours yes came with 3.55 with 6 speed
housings are same of course just gears installed are different
find a used one and pull cover off if the easiest way to determent what gear ration you have
 
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JRB

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Yes all 4 cylinder gassers were 4.10
Yours yes came with 3.55 with 6 speed
housings are same of course just gears installed are different
find a used one and pull cover off if the easiest way to determent what gear ration you have

Thanks for the reply tommudd.

For anyone new to libertys/ifs like me, the unit holding everything together comes up with the most search results as: front axle differential carrier.

These labeled as new units seem to be priced very reasonable and have 3.55 gears inside.
https://www.ebay.com/itm/3732028788...MIv8WQ_bvi8AIVm21vBB2YBwRXEAQYASABEgJnnPD_BwE

To avoid potential problems with used ones I'd like to pick up something like the link above beings the price is decent, does this look like a good candidate for my liberty? Unbolt old unit using procedures I found on here, swap in old axles if they look good and maybe have a fully functioning jeep again?
 

JRB

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Just updating this thread as I find more info in case it helps another liberty newbie, feel free to let me know if I've come across any bad information.

From my research there may be two differential carrier housings: one that is for 3.55 gears and under, and one for 3.73 gears and above. Seems to be the pinion gear may be larger on the higher number gears, and the max may be 4.10 or just above in these little gear sizes.

If that's the case I'll probably end up getting a junkyard 3.73 as the 4.10's are very scarce at the moment (probably in general) and at least I'll have a minor gear upgrade with the chance to regear without buying a new housing.
 

LabRat

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I'm really new to these things too. thanks to @LibertyTC I have used this link to find part names and numbers. It has a great illustrated parts breakdown for just about everything, including all the individual bits in your Diff. Might be cheaper to nickle and dime bits of the interwebs if the junkyards are a washout.

https://colorado4wheel.com/manuals/Jeep/KJ/06kj_PARTS_FICHE.pdf
 
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tommudd

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Just updating this thread as I find more info in case it helps another liberty newbie, feel free to let me know if I've come across any bad information.

From my research there may be two differential carrier housings: one that is for 3.55 gears and under, and one for 3.73 gears and above. Seems to be the pinion gear may be larger on the higher number gears, and the max may be 4.10 or just above in these little gear sizes.

If that's the case I'll probably end up getting a junkyard 3.73 as the 4.10's are very scarce at the moment (probably in general) and at least I'll have a minor gear upgrade with the chance to regear without buying a new housing.

Very few came with 3.55s( 5 and 6 speeds ) all automatic gassers came with 3.73s and easy to find
4.10s have always been a hard item to locate ,
I have been lucky enough that folks have found 4.10s for me over the years and let me know where they were
2 of mine have 4.10s with a " few extra " sets being rebuilt and will be ready when I find more 02-05s to build
 
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JRB

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Thanks @LabRat and @tommudd for the replies. The small dealer that overcharged me for a broken liberty, and the quick to find google parts results had me very discouraged, thanks for bringing some hope and needed motivation.

Current plan may be just to convert to 2wd mode while I search for exactly what I'll be doing, call me cheap or whatever but I hate spending money to maintain stock specs :p
 

LabRat

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Thanks @LabRat and @tommudd for the replies. The small dealer that overcharged me for a broken liberty, and the quick to find google parts results had me very discouraged, thanks for bringing some hope and needed motivation.

Current plan may be just to convert to 2wd mode while I search for exactly what I'll be doing, call me cheap or whatever but I hate spending money to maintain stock specs :p
Mine was in 2wd mode when I bought it. Thankfully it only took the previous owner a few weeks to find the forward prop shaft...which needed a front CV. Cheap rebuild. I got lucky ish.
 

JRB

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Was able to borrow a ride and got busy with work, back to research with the liberty. Current plan is convert to 2wd mode while I search for parts. If anyone knows of a used front carrier with 4.10's in it, please let me know!

Also if anyone knows: (since there seems to be confusion on lostjeeps and elsewhere of research) can a front axle assembly/carrier with 3.73 gears be re-geared to 4.10's?

Plan is if I can't find 4.10 carrier in whatever amount of time, I'll get a 3.73 carrier and wait to gear it to 4.10 on install, or gear both 3.73 now and down the road re-gear to 4.10's if I'm unhappy.
 

tommudd

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Was able to borrow a ride and got busy with work, back to research with the liberty. Current plan is convert to 2wd mode while I search for parts. If anyone knows of a used front carrier with 4.10's in it, please let me know!

Also if anyone knows: (since there seems to be confusion on lostjeeps and elsewhere of research) can a front axle assembly/carrier with 3.73 gears be re-geared to 4.10's?

Plan is if I can't find 4.10 carrier in whatever amount of time, I'll get a 3.73 carrier and wait to gear it to 4.10 on install, or gear both 3.73 now and down the road re-gear to 4.10's if I'm unhappy.
Confusion ????
No confusion anywhere
Yes you can regear a 3.73 to 4.10s
You should be able to find tons of 3.73s, heck I have even gave a few away to the junk man to get rid of them
 
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JRB

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Thanks for confirming that Tom.

The couple posts in this thread and the link to lostjeeps had me a little concerned with some of the replies, but after reading the threads again I could see who knew there stuff on the libertys.
https://www.jeepkj.com/threads/4-10s-in-a-2006-3-7l.53225/

Converting to 2wd mode starts tomrorrow, appreciate all the help everyone has given so far.
 

LabRat

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Yeah, it can be hard to separate the pros from the shade trees…but the Jeep cred of the mods/staff here checks out.

And I’m terminally **** enough to web stalk credibility to the same standard I hold my lab research to…

im a VW guy, but if you need support/shoulder to cry on, PM me.

It’s hard to learn on new vehicles.
 
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tommudd

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When I bought my 04 it was brand new, had less than 100 miles on it when they delivered it to me
installed hitch/wiring harness in my parents driveway, and hooked up a fully loaded trailer and moved 5 hours away ( best way to break one in, flat on the floor and good amount of weight going up the road )
I was coming from almost 30 years of SFA's ( Bobtail Broncos, full size Fords, Cherokees etc
Here was this thing with IFS and very weak / junk suspension ( in my book )
Started searching, found what is now LOSTJEEPs and within 5 months had OME lift with an ARB up front
Back then it was almost impossible to go more than 2.5 inches ( of course we pushed that boundary up some ) LOL
So yes new learning curve for sure if you have never worked on such a heap before ;)
 

LabRat

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I should add...I really am amazed at how easy these things are to work on however. The old military roots really show. ANYONE can learn to work on these things with minimal experience.
 
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