I am towing a 25.5 ft fifth wheel with a 1997 f150 4.6 liter, seems ok on level ground, but is sluggish on hills. I was told that I am killing the moter, but the tow rating for the truck is within specs, I am deciding weather or not to upgrade to a 5.4 or just rebuild the 4.6 as needed, the fuel economy is great with the 4.6.....ran about 200 miles on a tank/400klms....any info would be greatly apprecated...

 

A 5.4 will slow on the hills too..... If you expect to be able to maintain the same speed/rpms/gear on the hills as you do on the flats, then you will be disappointed for sure!

Nature of the beast with a gasser towing some #6000 of trailer up a hill and fighting the extra wind resistance a trailer is going to have.

Dropping into 2nd gear and pulling some 3000-3500 rpms to hold 50-55 mph is not "killing" an engine IMO.... That's what my 5.4 does when it's towing my #5000 TT up the hills. I'm not pedal to the floor either... It's just a nice steady pull.

As long as you are keeping your trucks fluids fresh, and that means all of the fluids that get overlooked like PS fluid, diff fluid, coolant, brake fluid... Trans and engine oil should be a given... You should be fine.

I've got 167,000 miles on my rig now, and it's not dead yet!

Take care of a hard working truck, and it will take care of you!

Good luck!

Mitch

 

I will have the diferential fluid changed, I never thought of that yet....https://www.f150online.com/galleries....cfm?gnum=8903[IMG]

 

Mitch, you have a nice truck and trailer, I looked at your pictures, very nice set up, I noticed your pics were viewed over 500 times in some cases, nice set up and lots of views as well, thanks again for the tip.....

 

Any towing or hauling will cause wear on your truck no matter what but that is what they are made for. As long as you stay within the factory spec for your rig you are fine. I pull a 24ft TT with my 97' 4.6L and it does the job just fine for me. I may not win any land speed records but she gets me where I need to go no problem. Also dont be affraid to run the engine in higher RPM range. The SOHC is made to work at higher RPM's just keep up on all your fluid changes.

 

how far have you towed your trailer? Can I feel confident towing the trailer to tennissee and back, the truck has about 100 thousand miles on it, or 214 kilometers, I am just afraid of blowing something up on the way, as sugested I will have all fluids changed and I have already done the moter and tranny as soon as I bought it, I think these dealers are trying to sell me a new truck, but I did notice on hills the speed noticeably decreases, but that part doesen't bother me as long as I keep trucken along....thanks for everything and the advice guys...very much appreciated!!

 

Since I pulled 6800# from Biloxi MS, to Homer, Alaska, (about 5,000 miles) with 140,000 miles at the time, I wouldnt be too worried...just dont try to go too fast, as the gas gauge and tranny temps will suffer. I got 4-6 MPG on the trip, and the tranny was definitely the weak link... not the engine. Slowed down when I could feel the heat radiating off the floor. Believe it or not, the mountains were less of a problem than the plains, with the wind (had a 3 horse trailer, which acted like a drag chute).

 

i thought my 8 mpg was horrible with a 5500# trailer.. lol

 

What is your rear gear ratio?

I've towed a 7000-lb. boat for years, things got much better when I re-geared to 4.10s, even with the supercharger.

 

160,000 kms is 100,000 miles just for future reference

I have been thinking about running 4.10s in mine I run 33" tires and will be towing 6000-7000lbs are the 4.10s low enough for ya? Are you towing on flat or really hilly highways? I will be towing through alot of mountains.

** I have a 97 4.6 LB reg cab**

 

The street tires I run (285-60R18) are about a 31.5-inch tire.

They are great for what I do, but mostly it's flat desert with just a little mountain/hilly stuff.

If you tow thru a lot of mountains with 33s, I'd look at 4.10s to start, but perhaps something a little lower may be better for you. I think I read in another post that 4.30 are available if you think 4.56 are too short...4.30 may be a good choice.

 

Yea thats what I was thinkin

 

the gears in my truck are 3.55, checked with the dealer. sorry about my math I thought you divided by 2.2 to go from klms to miles, now I realize it's 1.6...lol...learn something new every day