A1P2 and beyond ... rear axle mount pics

[coachgeo]

A1P2 is I believe the code for the first set of trucks that started using the Intermediate axle of a 6x6 as the primary rear axle. Does anyone have connections that can get pics or already has some pics of the spring perch mounts on these and later rear axles of the 4x4's with this setup? Curious if they use a kit to modify the 6x6 intermediate axle spring perches or of the axle has different perches molded into them.

Thank you in advance.

 

[scottmandu]

The A1's after 2007 have that rear axle. The P2 is specifically the up armored version.

View attachment 669279View attachment 669280

 

[scottmandu]

The axle tubes are different. There is a pad cast into the A1's for the leaf springs... The 6X6 has a different setup.

 

[coachgeo]

The axle tubes are different. There is a pad cast into the A1's for the leaf springs... The 6X6 has a different setup.

thanks for the pics. Was aware of how the Intermediate axle mounts on the 6x6 version as your pics show. Was wondering how they decided to go about mounting that axle on the 4x4 version. Figgered it was either retool some things at the factory and make Intermediate axle tubes with 4x4 spring perches or make a kit to convert OEM 6x6 Intermediate axle in order to make those fit as a 4x4 axles did. If they did a kit I was hoping to copy it. Guess I'll have to cut/ground off what's on my new one and have perches fabricated and welded to the tube that matches 4x4 mount.

Anyone see a conflict with welding onto these tubes?

Not that I care for my purposes... wonder if they redesigned and produce different innards of the Power Divider box since this 2007 and later 4x4 version does not need an additional differential?

 

[coachgeo]

The A1's after 2007 have that rear axle. The P2 is specifically the up armored version.

View attachment 669279View attachment 669280View attachment 669282View attachment 669283

for clarity....... seems pic 3 is a 2007+ axle with molded in Typical spring perches..... and Pic number 4 is similar axle with molded in perches for installing as a 6x6 axle. ( Pics one and two are missing)


Again thanks

 

[scottmandu]

why not use a center axle 3rd member in the rear axle of the 4X4? Why are you changing axles?

 

[scottmandu]

I don't know what the deal is with the two pictures. The 3rd picture is a 2010 M1078A1P2, and the other is my personal 2005 M1084A1.

 

[scottmandu]

Anyone see a conflict with welding onto these tubes?

They are ductile iron and require special processes to weld.

 

[coachgeo]

why not use a center axle 3rd member in the rear axle of the 4X4? Why are you changing axles?

the 6x6 Center/Intermediate axle has the pumpkin offset to one side to accommodate for its 3rd member/Power Divider box branching off toward the opposit side. The offset of the pumpkins brings the Power Divider's Ujoint back in line with Tranny. The pre 2007 4x4 axle housing has a different pumpkin offset. If one installed the center 3rd/power divider in a pre 2007 4x4 rear axle case then Driveshaft would not line up with tranny.

My goal in using Center/Intermediate axle is to raise rear driveshaft to horizontal in hopes it will increase the overall life of the machine. Overall life cause one it will keep driveshaft further up out of the way of trail rash and dings and two; cause a driveshaft at horizontal will not multiply vibrations thru driveline like sloped ones can. Suspect these two reasons is also why the 2007+ models went to this axle arrangement.


Info corrected. 3/4/17

 

[coachgeo]

They are ductile iron and require special processes to weld.

Thanks. Have some ideas that may not require welding. Basically, a complete new perch kit that clamps around square axle tube atop the 6x6 mount setup. Kit also utilizing some of the parts of the 6x6 perch for mounting it to axle tube.

 

[Johno176]

The drive line on any of these trucks is offset due to the transfer case. The only issue with using a 6x6 2nd member will be the lack of perch mounts. When you say: "the 6x6 Center axle has the pumpkin offset to one side to accommodate for the center's 3rd member/power divider box branching off toward the opposit side. The offset of the pumpkins brings the Power Divider's Ujoint back to the center line. Thus you can't use the center 3rd/power divider in a pre 2007 4x4 rear axle case in that manner cause then Driveshaft won't line up with tranny." not sure what you are trying to say here. When the drive line is engineered, a straight through set up is used. With this in mind, because the transfer case is offset, all the axle differentials are offset to form a straight driveline. The 6x6 drive shaft is not brought back to centerline. Pre 2007 or not, the driveshafts will line up. Rub here is the perch mounts, and also suppling air to axle to lock interaxle diff.

 

[sjohn116]

Steve6x6x6 has also pointed out that the bolt pattern is upside down when comparing a 6x6 intermediate axle vs the pre 2007 4x4 axle...thus preventing you from leaving your stock pre 2007 axle housing in place and just switching out the 3rd members.

 

[DiverDarrell]

A simple reason for the change is that it reduces the number of stocked parts in the supply chain. The axle change alone will save $$$$$

 

[coachgeo]

The drive line on any of these trucks is offset due to the transfer case. The only issue with using a 6x6 2nd member will be the lack of perch mounts. When you say: "the 6x6 Center axle has the pumpkin offset to one side to accommodate for the center's 3rd member/power divider box branching off toward the opposit side. The offset of the pumpkins brings the Power Divider's Ujoint back to the center line. Thus you can't use the center 3rd/power divider in a pre 2007 4x4 rear axle case in that manner cause then Driveshaft won't line up with tranny." not sure what you are trying to say here. When the drive line is engineered, a straight through set up is used. With this in mind, because the transfer case is offset, all the axle differentials are offset to form a straight driveline. The 6x6 drive shaft is not brought back to centerline. Pre 2007 or not, the driveshafts will line up. Rub here is the perch mounts, and also suppling air to axle to lock interaxle diff.

*My bad.. miss typed..... I should have said "inline" not "center line". Main Point is the pumpkin is offset in a different place on the Intermediate/Center axle compared to the 4x4 axle (pre 2007) .

You are correct; the air switch for the intermediate lock I will have to figure out. Open to you folks ideas. Does anyone happen to know the air pressure range needed to activate the switch?

*NOTE.... original post quoted above corrected to provide better info for future readers

 

[coachgeo]

They are ductile iron and require special processes to weld.

Scott are you sure it is not Ductile Steel?

 

[coachgeo]

Scott are you sure it is not Ductile Steel?

Spoke too soon Scott. found clarification..... https://www.meritor.com/productsandservices/defense/PDF/RT-611_Tandem_Axle.pdf that shows it is ductile iron. Much thanks.

 

[coachgeo]

side note: Was in a discussion with Bryce... and he has had folk buy an Indermediate 3rd/Power Divider from him and use the 4x4 axle with it . What they are doing is flip the axle to change the offset, clamp the spring mounts back on and clock the third/PD where needed and drill new holes into the housing to bolt it into that clocked position. (clock location =OEM intermediate axle's )