Does anyone know what a 1999-2003 F-550 "Optional High Capacity Trailer Tow Package" actually consists of? I have looked all over the web, read endless tow guides, called multiple fleet depts. & Ford directly. No luck. From what I have found so far, your truck must be:
: F-550 crew cab dually
: 7.3 diesel
: automatic tranny
: 4.88 gearing
: 176" wheel base (maybe)
this give you a 26k gcwr & a 17.5k fifth-wheel tow capacity, standard for F-550

The "Optional High Capacity Trailer Tow Package" bumps you to a 30k gcwr & a 21.5k fifth-wheel tow capacity. So far everyone agrees that it consists of at least:

: trailer wiring harness (7 pin)
: Aux. trans. oil cooler
: trailer brake wiring/feed kit
: synthetic fluid in rear axle
: frontal area increase to 90 sq.ft. (no clue what it means)

What no one seems to agree on is the following, so far:
: heavier rear axle
: heavier rear springs
: heavier rear shocks
: heavier rear frame rails
: all of the above
: none of the above

One way or another, you pick-up 4k in capacity. I have a hard time believing you pick it just with some wiring, a trans cooler & synthetic gear oil. But, maybe I'm wrong, hopefully I am, be much simpler.

Please help!

 

The 2000 - 2003 F550 FMC Specification manuals show same axles, springs, frame etc for the F550 no matter the package.

http://www.fleet.ford.com/truckbbas/.../techspec.html
http://www.fleet.ford.com/truckbbas/...2/fsersdcd.pdf

The "High Capacity Trailer Tow Package" option was only available on the F550 2WD CC with the 7.3 & auto trans.
http://www.fleet.ford.com/showroom/r...D_F350_550.pdf

"High Capacity Trailer Tow Package (535) is available with F-550 Crew Cab 4x2 and includes Trailer Tow Package (531), synthetic lube in rear axle, and radiator in-tank transmission oil cooler."
http://www.fleet.ford.com/showroom/r...er_weights.pdf

 

Thanks a million for the info. I never would have believed synthetic lube & an in-tank tranny cooler would give that extra capacity like that. I have a couple more questions you could probably answer also. Dont all auto matic trannys have a radiator in-tank transmission oil cooler installed or is this something different. And the 2nd question, could you install the same equipment on your own F-550 or even an F-450, & get that higher tow rating?

 

Some vehicles had only air to air transcoolers, some only in-tank coolers and others had both. The hot setup on the 7.3 & auto trans is to upgrade to the 6.0 air to air trans cooler. It is a direct bolt on replacement, best $278 you can spend.
http://www.directfordparts.com/partl...=1&catalogid=2

Well it appears by reading the specs charts on those links that the F450/550 share the same axles and frame. So with the 4.88 gears and mechanical upgrades you would meet FMC weight specifications. However you would not change the GVWR sticker on your truck B-Pillar. Since you are commercial and depending on your state regulations you should be able to register for whatever weight rating you want to pay for.

Also drop down to the 7.3 forum and read up on the modifications to both the engine and transmission.

 

I've got a 550 rated at 19k gvw instead of the standard 17.5k but cant provide any more info as I bought it used

 

Thanks again. I will drop down to the 7.3 forum & get the latest scoop. Do you think the 7.3 is the way to go or should I consider the 6.0? I'v heard alot of negative about the 6.0. What do you think?.

 

There is an open ended question.
I don't think you can go wrong with either engine, i have a 6.0 and have had no problems and love it. The advantage to the 6.0 is more power off the shelf than the 7.3 and the Torqueshift transmission. The Torqueshift transmission is superior to anything currently on the road IMO. You will find supporters and detractor for each engine. Might as well throw the V-10 in there to get a real war started.

There is a ton of information on this question here at FTE read the 7.3 & 6.0 forums, then choose the best option for your pocket book and needs.

 

I would say over all the 7.3 is known to be a more reliable engine, not to say that all 6.0 are junk it's just that many were and it's given the good ones a bad wrap. The torqueshift is a better tranny, but there are some 4R100 builders out there that make tranny's just as relibable as the torqueshift. (i.e. BTS, etc.) I own a 7.3 and would never own a 6.0L just because of the reliablity concerns. Basically go with what ever your heart desires, and pocket book can afford. I'm not going to start bashing engines the debate will go on forever, and ever, and ever. It's just what ever you prefer, they each have there strengths and weaknesses, I think we can all agree that they are better than anything chevy or dodge can offer.

 

Apologies in advanced for replying to an ancient post...

Perusing the Ford parts catalog, it would appear that the "heavy duty trailer towing package" used a 36 spline S130 axle with an eaton true track.