'Ol Builder guy
Join Date: Dec 2008
Thanked 99 Times in 73 Posts
I'm not gonna try to overspeak what Randy says, but I'm looking right at the "Trailer Tow Package, High Capacity (535)" (for an F-550) Here's what it says:
* Optional on all F-550 Chassis Cabs
Not Available With:
*Ambulance Prep Package
*6.4L Powerstroke diesel engine (99R) and 4.88 Limited Slip rear axle (X8L)
* Aftermarket trailer brake Wiring Kit (not ordered if ordered w/52B Tow Command Integrated Trailer Brake Controller)
* Increases GCWR on diesel engine w/ manual transmission from 26,000lbs to 28,000 lbs
* Increases GGCWR on diesel engine w/auto transmission from 26,000lbs to 33,000 lbs
* UPGRADED REAR AXLE
* Trailer brake Contoller not included
All older versions used to have a Dana 80 in the F450, and all 550's used to have a Dana 135's.
What I'm thinking is that the 450 and 550 now come with Dana Spicer 110 axles. If you get the 550 with the HCT package, they give you back the Dana 135.
I think that ford might have switched the 450 & 550 to a Dana 110 since it's heavy enough for either truck and decided to reserve the Dana 135 for the HCT package F550 only.
Just an educated guess....