Destroyed three sets of 4:56 ring pinion 7.5

[4x4junkie]

I think it was very late-'90s models (before the FX4 came around). They still may as well be unicorns, I've only seen ONE report of anyone having seen one, myself (probably the same one as you, I don't recall who it was).

I've never seen the FX4 (level II) options that started in '02 include anything but 4.10 gears.

 

[Wicked_Sludge]

late 90's would most likely make it a 28 spline axle...i know for sure it was a 31 spline we were discussing (i honestly cant recall the details of the truck or the users name, it was too long ago). the tech library says all '99+ 4.56 geared axles are 31 spline.

 

[Bent Bolt]

I've had the parts guys at work check for me awhile ago. 4.56 gears were never offered in any RBV axle.

 

[Wicked_Sludge]

then why does ford specify an axle code for both a l/s 8.8 with 4.56's and an open 8.8 with 4.56's?

 

[Bent Bolt]

Dunno, I've looked in the G-CAT myself. No mention of any 4.56 gears.