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partsman01 · 03-27-2006, 07:56 AM

Okay, figure I will ask here.
I am new as of last year to towing, we bought a used 1989 18.5 Prowler Lynx fifth wheel.

I drive an old 1977 F-250 super cab, it has a 400CI or 6.6 litre engine, with a C6 transmission, with a tranny cooler, but it does not appear to be a real big one.
I have the spare tire mounted on the front.

My gear ratio is 3.73, and my question is when going up hills should I shift it down to second and run at a slower speed, and same for downhill, should I shift down and go down slowly?
And if I run at a slower speed, is there a lower limit to try and keep the speed at?
I know when I towed for the first time last year, a lot of people were passing and some of them were towing.
I hope to avoid doing in the tranny on the truck.
Thanks for any and all advice.

partsman01 · 03-27-2006, 07:56 AM

Okay, figure I will ask here.
I am new as of last year to towing, we bought a used 1989 18.5 Prowler Lynx fifth wheel.

I drive an old 1977 F-250 super cab, it has a 400CI or 6.6 litre engine, with a C6 transmission, with a tranny cooler, but it does not appear to be a real big one.
I have the spare tire mounted on the front.

My gear ratio is 3.73, and my question is when going up hills should I shift it down to second and run at a slower speed, and same for downhill, should I shift down and go down slowly?
And if I run at a slower speed, is there a lower limit to try and keep the speed at?
I know when I towed for the first time last year, a lot of people were passing and some of them were towing.
I hope to avoid doing in the tranny on the truck.
Thanks for any and all advice.

RKamperRV · 03-27-2006, 08:26 AM

Your truck should have little trouble with that trailer. Watch your RPMs. If it seems like the engine is bogging down or starting to overheat, then downshift. Grade (% incline) plays a big part in the performance of the rig. I would recommend you remove the spare from the front and stow it in the bed. Keeping maximum airflow is important, especially on hotter days.

Going downhill, let your trailer brakes do much of the work slowing the rig. If you find yourself braking excessively, then downshift one gear and let the tranny and engine hold you back.

Many roads, especially Interstates, do have a minimum speed, so be aware of what road you are on and what the local conditions and restrictions are. If you are on a 2-lane road and traffic starts backing up behind you, pull over and let them go by. Being courteous to those behind you helps the rest of the world tolerate us RVers.

Two Bit · 03-27-2006, 09:12 AM

Your truck has one of the toughest automatic transmissions Ford has ever made. Change the fluid regularly, dont overheat them, and the C6 lasts a long time. I would suggest a transmission temperature gauge. Temperatures can go up when climbing a hill too fast. The gauge will let you know when to downshift and slow down. Use 220 degrees F. as a maximum. Also it would not hurt to have a radiator shop remove and clean your radiator. At it's age it can/will be partially clogged. After you install a gauge, if you find the trans temperatures too high, put a bigger trans cooler on it.
My 87 460 engine had a trans cooler and an engine oil cooler on it. You may be able to fit a engine oil cooler from a 460 onto a 400 to give you extra cooling. Your truck should do fine with that trailer. If you want extra power, put on a Holley carburetor and better exhaust (headers and a Flowmaster muffler). The big Ford V8's respond best to intake and exhaust improvements. If your emission laws alllow it, get rid of all the air pump plumbing on the engine.

sawtooth · 03-27-2006, 12:00 PM

Good advice here.

http://www.canadiandriver.com/articles/jk/at_000724.htm

partsman01 · 03-27-2006, 08:23 PM

Thanks for all the replies,I will take the spare tire off the front.
Will also see if I can figure out what rating the tranny cooler has, it does not seem to big to me.
I did put a new aftermarket rad on a couple years ago.
I have been given an electric fan, I have to figure out if it is push or pull type.
If I have space, I think I will install it, plus I think I will get a temp gauge for the tranny too.
I should mention it is a dual fuel, it is gas and propane, and seems to not be as powerful on the propane.

WD40 · 04-03-2006, 09:29 PM

Hello Partsman: At one time I had a truck all most like the one you have. Like others have said the C-6 is a tough old dog and will talk a lot of hard work.
I would put a temp gage on the transmission, and while I had the pan dropped on it I would change out the oil filter and also put in a Street Shift Kit. No racing or heave duty kit.
You will never know it there tell you hook up the RV. Put a tack on your truck also.
Make sure the temp gage on your truck is in perfect working order. The 400 is a bored out 390 and the water jackets are a little thin, so be sure not to over heat the motor.
You should be able to pull up to a 26 or some 28 footers with this setup.