AAM 9.25 inner axles??? Where to buy

[ENafziger]

Does anyone know where I can buy inner axles for the AAM 9. 25 front axle? I've found one place that sells the inner/outer/ujoint assembly as a whole, but I only need the inners. I'd prefer to upgrade to 4130 chromoly shafts if possible, but anything will do right now.

Thanks, Eric

 

[superswamper]

I broke my axle shaft and got a new one from the dealer, the cost of the inner was a little less than the whole thing. The axle joints are pricey so it was a no brainer there and it was a quicker fix...

 

[dlmartin]

Republic Diesel-Louisville & Lexington Ky

 

[JCrockett]

Chrysler / Dodge / Plymouth 1 Ton Dodge Pickup Front Differentials Chrysler 9. 25 AAM Axles & Axle Bearings Auto Parts: YA C5086666AB, YA C5086667AB,



Doesnt look like Superior Axle and Gear make a set. .

 

[ENafziger]

Hey! Thanks for the above link... this has got me on the right track.

I've found so far replacement axles made from 1540 and 4340... I assume the logical choice here is 4340?

This may be more than what anyone here wants to know, but I found it quite interesting:

Most OEM shafts are 1040-1050 but some may also be 1541. Most aftermarket stock replacement shaft are 1541 and most of the custom rear flanged axles like all the Currie, Dynatrac, Dutchman, and Moser rear shafts are 1541. 1541 is a plain high carbon steel similar to 1040 but with added manganese for better hardenability, but there is not enough alloying elements in it to be classified as an "alloy" steel. 1040 & 1541 are used because it is cheap and good enough for what is required by stock axles, they heat treat 1040 & 1541 by induction hardening which is a production form of case hardening, it is fast, cheap and works very well, 1541 is able be be hardened to a greater depth (better hardenability) than 1040/1050 and therefore stronger. 1541 is not much more expensive than 1040/1050, it probably equates to only a dollar or two more per axle, when your dealing with the scale of OEM axle production numbers that is a lot of money, but with aftermarket axle production numbers that is not that big of a deal and the consumers would pay that extra amount without question for the increased strength.

4140, 4340 and 300M are true alloy steels. 4140 is alloyed with chromium, molydenum and 4340 with chromiun, molydenum and nickel. 300M is also called 4340 modified because it basically 4340 with silicon added. The strength of steel is generally directly related to the hardness, the harder you can get the steel, the stronger it is (tensile strength) but you generally loose toughness. These alloys give the steel increased hardenability and good toughness at higher hardness/strength levels, they can be induction hardened but their purpose and advantage is that they can be thru hardened because of their better hardenability. 4340 has better hardenability than 4140 so is can be heat treated harder and thus stronger than 4140. 300M has a similar hardenability to 4340 but the added silicon gives it more toughness at higher hardness levels. The 4140 and 4340 raw material is available in commercial and aircraft quality and 300M is generally only available in aircraft quality. Aircraft quality means it is vacuum melted to minimize the impurities but costs more. Most 4140 and 4340 axles are made of commercial quality steel. The material cost differrences between 1541 and commercial 4140/4340 is not that great, again it probably only equates to only a few dollars more per axle, the big cost difference is from the increased heat treating costs and the smaller production runs of 4340 axles. 4140 and 4340 axles have to be thru hardened in an oven which costs more than induction hardening of a 1541 or 1040 axle. 300M should be heat treated in a vacuum furnace and other expensive process to make it correctly plus the added material costs for aircraft quality materal make the end product more expensive. 300M axles are usually custom made, a few sets at a time which adds to the production costs.

--Eric<!-- / message -->

 

[Bob4x4]

Are your old axles loose at the u-joint or something else?

 

[ENafziger]

Are your old axles loose at the u-joint or something else?

Horribly loose, but just the inners. There's nearly 1/4" of play!!! The outers are fine as they are the upgraded ones I just installed with the Dynatrac hub kit. I got one of the bad first batches of Carli lower bjs, and both lowers snapped sometime on our 10,000 mile trip to Alaska...

--Eric

 

[ENafziger]

Well, back to square one. I just got an email that said the 4340s are backordered 6 - 12 months! It makes me wonder if they've even been released yet.

--Eric

 

[ENafziger]

Well, found out they haven't been released.

PolyPerformance.com sells a nice set of axles for $1,995 They don't say what material it is, but it's out of my budget either way.

Still looking...

--Eric

 

[AH64ID]

Have you found anything else?

I see you have 37's, but that shouldn't effect the inners unless you do a lot of off road driving in 4wd. How many miles on them?

 

[Yo Hoot]

Hey! Thanks for the above link... this has got me on the right track.



I've found so far replacement axles made from 1540 and 4340... I assume the logical choice here is 4340?



This may be more than what anyone here wants to know, but I found it quite interesting:



Most OEM shafts are 1040-1050 but some may also be 1541. Most aftermarket stock replacement shaft are 1541 and most of the custom rear flanged axles like all the Currie, Dynatrac, Dutchman, and Moser rear shafts are 1541. 1541 is a plain high carbon steel similar to 1040 but with added manganese for better hardenability, but there is not enough alloying elements in it to be classified as an "alloy" steel. 1040 & 1541 are used because it is cheap and good enough for what is required by stock axles, they heat treat 1040 & 1541 by induction hardening which is a production form of case hardening, it is fast, cheap and works very well, 1541 is able be be hardened to a greater depth (better hardenability) than 1040/1050 and therefore stronger. 1541 is not much more expensive than 1040/1050, it probably equates to only a dollar or two more per axle, when your dealing with the scale of OEM axle production numbers that is a lot of money, but with aftermarket axle production numbers that is not that big of a deal and the consumers would pay that extra amount without question for the increased strength.



4140, 4340 and 300M are true alloy steels. 4140 is alloyed with chromium, molydenum and 4340 with chromiun, molydenum and nickel. 300M is also called 4340 modified because it basically 4340 with silicon added. The strength of steel is generally directly related to the hardness, the harder you can get the steel, the stronger it is (tensile strength) but you generally loose toughness. These alloys give the steel increased hardenability and good toughness at higher hardness/strength levels, they can be induction hardened but their purpose and advantage is that they can be thru hardened because of their better hardenability. 4340 has better hardenability than 4140 so is can be heat treated harder and thus stronger than 4140. 300M has a similar hardenability to 4340 but the added silicon gives it more toughness at higher hardness levels. The 4140 and 4340 raw material is available in commercial and aircraft quality and 300M is generally only available in aircraft quality. Aircraft quality means it is vacuum melted to minimize the impurities but costs more. Most 4140 and 4340 axles are made of commercial quality steel. The material cost differrences between 1541 and commercial 4140/4340 is not that great, again it probably only equates to only a few dollars more per axle, the big cost difference is from the increased heat treating costs and the smaller production runs of 4340 axles. 4140 and 4340 axles have to be thru hardened in an oven which costs more than induction hardening of a 1541 or 1040 axle. 300M should be heat treated in a vacuum furnace and other expensive process to make it correctly plus the added material costs for aircraft quality materal make the end product more expensive. 300M axles are usually custom made, a few sets at a time which adds to the production costs.



--Eric<!-- / message -->

Wow, thanks for all that knowledge!

 

[DGamelin]

Thanks for the info. I am about to narrow a set of axles, this helps with my learing curve.



_________________________

93 250 2wd xc 354 auto 278k

04. 5 3500 4wd qc dully 373 6speed 116k

 

[Bob4x4]

Have you found anything else?



I see you have 37's, but that shouldn't effect the inners unless you do a lot of off road driving in 4wd. How many miles on them?

I work on trucks that see desert use and yes the inners are affected. I have seen them stretched as low as 10k miles.

 

[AH64ID]

Thanks for the info. I am about to narrow a set of axles, this helps with my learing curve.

What's the project?

I work on trucks that see desert use and yes the inners are affected. I have seen them stretched as low as 10k miles.

Wow, thats early wear. I guess they still are built for 95% of customers.

 

[Bob4x4]

Not so much wear as the material is too weak in some applications

 

[DGamelin]

AH64ID, an 04 jeep TJ unlimited, we went to TX to get a salt free one. The plan is to get the axles and suspension built this winter and next winter it will get a cummins 4 cly.



dont mean to steal a post.



________________________

93 250 2wd xc 354 auto 278

04. 5 3500 4wd qc dully 373 6speed 116k

 

[AH64ID]

DG. . sounds like a SWEET project!

 

[ENafziger]

Have you found anything else?

I see you have 37's, but that shouldn't effect the inners unless you do a lot of off road driving in 4wd. How many miles on them?<!-- google_ad_section_end --> <!-- / message --><!-- sig -->

I ended up ordering some Yukon 1540 series alloy shafts that I found in stock at Randy's Ring and Pinion. Total cost for both was about $300 with free shipping. These are supposed to offer slight increase in strength over the stock axles, but nothing close to the 4340s that are backordered.

I wouldn't say that I do ALOT of offroading. The truck has 99k miles on it, and probably less than 1k of those were in 4wd. However, previous to the Dynatrac conversion, the axles were spinning ALL the time.

I think most of the wear occurred on the Alaska trip in July, simply because the inner axles showed NO wear when I installed the Dyanatrac kit a few months before the trip.

We ran about 500 miles offroad in Alaska/Canada grossing 20,325 lbs. With the Carli suspension, I was able to safely run 45 - 55 mph on roads that otherwise would've required speeds of 20 mph or so. Much of this was STEEP grades, boosting 40 psi + for a significant percentage of the offroading.

It's really hard to take a picture of how steep something is, because it seldom looks as harsh in a picture as it seemed in real life; nonetheless, here's a few pictures of what did the axle shafts in:

#ad


#ad

#ad

#ad


#ad

Here was the rig:

#ad

 

[ENafziger]

dont mean to steal a post.

Steal away! ... no problems here! Sounds like a great project!

--Eric

 

[ENafziger]

Randy's ring and pinion ships quick! Both new axles are here already!

I was under the assumption that I ordered only the inner axles... however, I really ordered the complete inner/outer assemblies with u-joints. I'd normally be really excited, since it would be just a complete drop-in replacement. But, the Dynatrac kit uses different outer axles, so I'll have to disassemble these and use the 35 spline Dynatrac outers.

I can't believe these were only $138 each though, since they include the inner/u-joint/outer assembly. I'll take some pictures this weekend during the install.

--Eric