Ford Class A "F53" Chassis 101
JanOrme
start this thread of known FACTS. I am not an expert but have gathered
information about this Chassis because of my own purchase.
Why this particular chassis?
Because this gas chassis is with out doubt the most popular and largest selling
Class A. It is selling like hotcakes and for some good reasons. There is no
perfect chassis but right now this is the E ticket for Class A Gas. And because
there seems to be an attitude here by some with half truths, bad information
and no real research. I get the feeling that some are going to be extremely
pissed if this chassis in combination with some nice coaches ends up to be
viable. Some kind of attitude of, "it ain't never been any good for 40 years
and it never can be!" Or......an actual comment of, "Many MH Chassis have such
limited towing capacity that towing a car is out of the question unless owners
take the chance of ignoring the safe limits established by the makers."
Here is what I will try to lay down in several notes:
1) Post some '97 Ford chassis towing guide info.
2) Post some '99 Ford Motorhome Class A Chassis manual information.
3) Explain some differences between older F53s and the current evolution.
4) List the changes made to the '99 chassis.
5) Discuss why/how you can or cannot tow a considerable weight toad.
6) Show certified weights of a rather large, fully optioned, fully laden, 2
slide, heavy and extended frame 102" X 36' Class A in combination with a toad.
Will it be in spec? Guess now if you want to.
7) How does that bib beast perform?
Items 1 & 2 in the next note.
Jan Eric Orme
Walnut Creek, Ca
JanOrme
Item 1 - '97 Towing Guide info:
The 1997 Ford Recreation Vehicle and Trailer Towing Guide under "Ford F-Super
Duty Class A Motorhome Chassis" says:
"-15,200# and 17,000# Gross Vehicle Weight Ratings (GVWR)
-25,000# Gross Combination Weight Rating (GCWR) for excellant towing capability
(8,000# maximum trailer weight at 17,000# GVWR)
-7.5 EFI V-8 engine offering 245 horsepower and 400 lbs-ft. of torque for
plenty of power and performance"
"Many motorhome owners enjoy the convenience of having another vehicle along
when they travel. In fact, towing another vehicle behind a motorhome has become
more popular in recent years. For safe operation, towed vehicles, or dollies or
trailers carring them, should be equipped with a separate functioning brake
system."
The words in quotes are from the guide. There is more but not about ratings.
Item 2- 1999 Ford Class A Chassis Manual, various statements from pages 32, 33,
34 and 35:
GVWR: Maximum total weight of the base vehicle, passengers, optional equipment
and cargo.
GCWR: Maximum combined weight of towing vehicle (including passengers and
cargo) and the trailer. The GCWR indicates the maximum loaded weight that the
vehicle is allowed to tow.
Maximum Trailer Weight: Maximum weight of a trailer the loaded vehicle
(including passengers and cargo) is permitted to tow. It is determined by
subtracting the weight of the loaded trailer towing vehicle from the GCWR for
the towing vehicle.
Calculating the load your vehicle can carry/tow:
(Lots of words...to summerize they want you to weigh the vehicle and use the
chart.)
Trailer Towing: Your vehicle can tow a class I, II or III trailer provided the
maximum trailer weight is less than or equal to the maximum trailer weight
listed for your engine and rear axle ratio on the following chart:
Engine: 6.8L; Rear Axle Ratio: 5.38; Maximum GCWR: 26,000#; Trailer Weight
Range (0-Maximum): 0-10,500#; Maximum Frontal Area of Trailer-ft squared: 60
sq. ft.
For high altitude operation reduce GCW by 2% per 1,000 ft. of elevation.
Trailer Brakes: Electric brakes and manual, automatic or surge-type brakes are
safe if installed properly and adjusted to the manufacturer's specifications.
The trailer brakes must meet local and Federal regulations.
Do not connect a trailers's hydraulic brake system directly to your vehicle's
brake system. Your vehicle may not have enough braking power and your chances
of having a collision greatly increase.
The towing vehicle braking system is rated for operation at the GVWR, not the
GCWR.
Separate functioning brake systems are required for safe control of towed
vehicles and trailers weighing more than 1,500# when loaded.
There is more such as: Base Curb Weight, Payload, GVW, GAWR etc. plus
trailering tips and info. but this is the meat of it. If you want more let me
know.
Items 3 & 4 in the next note.
Jan Orme
DJOsborn
CAUTION! CAUTION! CAUTION! You are exposing yourself to unbelievable
criticism, insults, and name-calling if you introduce FACTS to this newsgroup!
73,
David, N8DO; FMCA 147762
The correct address is djosborn at aol dot com
JanOrme
Items 3 & 4 Differences in older F53 and changes to the new F53:
There seems to be some confusion about "F53". This same designation is still
used but it has evolved into something different and better. Sometime during
the '98 model year the newer 1999 version of the chassis started showing up
with the V-10.
The older 460 V-8 setrup had 15,200 & 17,000# GVWR and 25,000# GCWR.
Here are some very remarkable and sugnificant changes for the '99 chassis.
Please note that some of this info comes from another BB and Robyn Spets:
-81" Front tread width, (over 9" wider than the previous years) which makes for
obvious better handling and stability even when parked. Along with that the
front frame was widened by 7.9" and the spring perches & shackles are hung
outboard to accpomodate the new wider monobeam axle. The front tapered leaf
springs are now 63" long. The front axle is now rated at 7000# (up 1000# from
previous). maximum turning angle for '99 is up 7.7" sharper for smaller turning
diameter and better manuverability.
- In the rear the 4" X64" long springs now have a rating for that axle of
13,500# (in the larger rated 20,500# version) up 2500# for '99. The rear tread
width has been increased over 2".
-New 19.5" wheels with only 8 lug nuts rather than 10 now accomodate commercial
12 ply load range "F" tires rather than the previous load range "E" tires on
16" wheels.
- The old brakes were 4 wheel disc but had rear ant-lock only. The new 4 wheel
disc brakes have 4 wheel anti-lock ABS. The larger 20.5K chassis alo has
HydroMax 21.1:1 ratio booster rather than the smaller HyroBoost 8.19:1 ratio on
the smaller capacity rigs.
-From the factory wheelbases for '99 are 178", 190", 208" and 228". Some
motorhome manufacturerers stretch the chassis. More on that later.
-Does somebody brag to you about their Dana 80 rear end? For '99 in the 20.5K
chassis the '99 has a Dana S135 in it's bayonet housing (far stronger than
swaged tubes in a braced pumpkin) and a fill of SAE 75W140 Synthetic Lube from
the factory.
-For '99 as you may know, the 4R100 Transmission is improved over the previous
E4OD. The tranny includes "lock-up" gears when in park. There is also a tranny
mounted driveline parking brake.
-Horsepower in the V-10 is up 10 over the '98 V-10 and 30 more than the old V-8
to 275 HP @ 4250 RPM. Torque is 410 @ 2650 RPM which translates to the 60-65
mph sweet spot in 4th.
-The chassis comes wired for Class II-IV. Alternator is 130 Amp. Battery is
750 CCA 78 Amp-hour. 75 Gal. gas tank. 1.63" gas shocks.
For a decent look go to:
www.fleet.ford.com/vehicles/detailClassA.asp
In the next part 4 note items 5, 6 & 7.
Jan Orme
wi...@epix.net
In Article<19990227000229...@ng-cc1.aol.com>,
<jan...@aol.com> writes:
> Because of the roaring flame on this subject I am going to jump in
>here and start this thread of known FACTS.
Jan has provided some very good information, though admittedly focused
sharply on ONE chassis. The information certainly is 'authoritative'
in view of it's source. So the question of interest to rv travelers is
not whether the information is good, but whether it applies to THEM.
I'm sorry some folks seem to regard any appearance of disagreement
as "flame" but since I am not running for office I offer some
counterpoints. These are not offered to dispute Jan's information, but
to caution that it may not apply to every reader with a MH, and that
it is not necessarily the whole story.
1) Not all motorhomes are built on Ford F53 chassis. In fact, not all
MH's are built on Ford chassis. It is foolhardy to assume these
numbers apply to your rig unless you have the same rig.
2) Not all coachbuilders conform to the Ford weight limits. It is
well and amply proven that MANY MH's are still leaving the dealer's
lot overloaded or so close to it that yer grandkid's butterfly
collection puts it over the limit.
3) A question arises after perusing the data: Have YOU, dear MH owner,
researched YOUR chassis limits as well as Jan?
4) If you said YES to #3 above, what kind of toad braking are you
using? Your toad DOES weigh over 1500 lbs, right?
On towing: Having towed several kinds of trailers and cars behind
trucks, cars, and (yes) motorhomes for 40+ years, I continue to
counsel that you should not try to tow more than about 75% of what the
maker specifies as a maximum tow rating. I have stated the reasons for
this conservative recommendation many times; but in brief it is
because a lighter-than-max load allows a bigger margin for long/steep
grades, bad roads, modern highway speeds, driver inexperience, and
most of all emergency maneuvers. This last is especially crucial with
motorhomes because of the long rear overhang and the tendency for a
toad to chase the back end off into the puckerbrush.
I fully realize my views are unpopular - not just with self-appointed
hecklers but with many of you who think it MUST be OK to tow a Town
Car or huge SUV because you see other people doing it. I'm more
conservative than most folks because I've been there and realize we
are ALL better off if we are not pushing ourselves and our equipment
to and beyond it's capability.
The salesman and the factory people writing glossy brochures will tell
you almost anything to get your money. The braggarts around the
campfire will tell you their Intrepid hauls that 9,600 lb Airstream
"like it wasn't there"; the guy with an old Dodge Jamboree class C
towing a race car and all its spare parts in a trailer will tell you
it's "No Problem". If you are the sort of person who values advice
given by people bravely defending their decisions or seeking to get
your money, then you deserve what you get!!
Will KD3XR
JanOrme
One not of caution just came to mind about second-stage manufacturerers (a.k.a.
motorhome builders). The date a builder completes the unit can legally be
considered a '99. This makes it possible that they could build a '99 on the
older style chassis that has been in storage. LOOK CLOSE! The wider front
stance of the new chassis is a dead giveaway.
Item 5: Can you tow a considerable weight toad? Short answer is yes. IF you set
it up correctly.you could obviously from the info given tow that old Linclon
battleship. Would you want to? I would not but whatever floats yer boat! IMHO
you should pick a toad that is as light as possible and equip it with an
adequate brake system to make it comply with Ford guidelines. This does mean
that some may opt to tow a nice small SUV 4x4 sucas Jeep or Honda CR-V that
weighs around 3500#.
Item 6. - That big MH and the weights.
The MH I weighed is my own. It is a 102" x 36' long pup with 2 very large
slides. It may be about as heavy and equiped as you could go. It is simply what
we wanted. This particular manufacturer takes the 228" WB chassis and stretches
it to 242" to get a good WB/Length ratio but more weight. J.D. at RVCG says he
thinks the method of extending the rails is as strong or stronger than factory
and preferable over a tag axle. The coach has all options and upgrades you
could imagine such as 2 roof airs, 2 tvs, double frig with ice maker and all
the gizmos. Added above the option list is stuff like special ordered dresser
cabinets and extra awnings all around. This maker uses a welded steel cage and
heavy support floor frame. This all adds up to more weight!
How was it equipped and weighed ? When weighed it had 2 passengers, full 90 gal
water tank, full 19 gal LP tank, full 75 gal gas tank, all normal provisions
for travel such as food, appliances, dishes etc. Normal basement items such as
tools, spare, misc parts, hoses, wood blocks (I carry a bunch) etc. The toad is
a '98 Cavalier 4 door with automatic and is equipped with a complete brake
system including all hardware and air tank to activate the brakes. The combined
rig is equiped with
a heavy steel Roadmaster Falcon Tow Bar and brackets set up including locks
etc.. No aluminum for me. A "dirt skirt" has been installed at the rear of the
MH. I purposely waited to weigh this rig until I had all the "stuff" in or on
it.
When weighed at a certified scale method was with the entire rig hooked up on
approach to the scale: Three weights were taken. First weight was the front
axle, then both MH axles and then the entire rig with toad.
Weights are:
Front Axle: 6540#
Front & Rear MH Axle: 19,860#
Complete Combination: 22,700#
Rail away! Yes it's heavy (we knew it would be) but it is loaded out and in
spec!
Translation:
Front Axle: 6540#
Rear Axle: 13,320#
Total MH: 19,860#
Toad: 2,840#
Total Combination: 22,700#
Item 7 - How does it perform?
Damn well. About 2K on the clock now. Pulled the entrance road (with the combo)
16% grade to Laguna Seca Raceway with no problem. Have had it in some severe
weather and it tracks and does well. The combined brake system works well.
Early mileage is around 7+. Will know more and have better data after some
more miles. Next Wednesday I leave for a trip to Lancaster over the Grapevine
and return. Then I will know more about performance. During that trip I plan to
tour the factory of the unit.
Can you tow a sustantial trailer or toad with the F53? Yes you can.
Jan Orme
DJOsborn
Which I think is a long-winded way of saying, "I now realize I was wrong
about the Ford Class A Chassis (since it was upon a quote from that chassis
owner's manual that I based my statements) but I simply cannot bring myself to
admit it. Therefore, I'll attempt to confuse the original issue with lots of
words containing related, but not pertinent, material."