Here's the deal, I have a 2001 F150 scab with a 4.6L V8 and 3.73 rear end. I have a camper trailer that weighs about 4,000 to 4,200 lbs (about 3,840 lbs dry). My truck struggles to pull it, mainly keeping highway speed and obviously on big hills. Has anyone else found there 4.6's to be very underpowered? I hate pulling this trailer (its a 1998 and pulls like a brick wall). Any input? Should I be having this kind of trouble pulling that much weight?

 

I wouldn't think so. Do you tow with the OD off ? Mine is a 5.4 so I couldn't tell you exactly but I tow twice that much without a whole lot of struggle.

 

Yup, OD is off. On some bigger hills I'll be down to first gear crawling at about 50 to kms/hr. My bro-in-law had roughly the same weight of trailer but drives a Pathfinder and passes me on the hills, pretty embarassing.

 

Are all your truck and trailer tires inflated properly? Are the trailer brakes dragging?

Does your truck run like it should without the trailer, or is it always pretty weak?

Any chance your flow master and tuning have cost you low end and mid-range power?

Seems to me it should not struggle that much with 4,000+- lbs, though that is a fairly respectable load. Maybe your actual trailer weight is heavier. Do you have the truck bed and cab filled with heavy stuff when towing the trailer?

Nice looking truck, BTW.

 

I wouldn't think you should have a problem. I've towed 3000lbs with my previous truck 4.0 V6 Ranger with a 4:10 rear end without problems.

 

It shouldn't be a problem for your truck. I'd recommend swapping out the fuel filter, as if this is even slightly blocked it can starve the engine of the extra fuel needed to tow. If that doesn't help I'd do a full fluid swap on the tranny and make sure your springs and such are all up to spec, you may have a transmission that's not locking properly and can't get the power to the pavement.

 

If your truck cant pull 4000 pounds then you must not be in a ford

 

Correction, I checked my spec sheet and I have a 3.55 rear end, not 3.73, I guess that makes a bit of a difference. I've thought about the trailer weight not being accurate, next weekend I will take my bro in-law's trailer (about 3200 lbs dry) out for a test tow, see if there is any difference. Diff fluids have ben changed recently and the tranny was flushed maybe about 25,000 to 30,000 kms ago. I bought the tuner shortly after I bought the trailer to see if it would improve things but it didn't do much. I've found that my tranny does a weird thing in 1st, when I take off (no load) the rpms go up then down, then back up again without letting off the gas, i.e. it does it under constant acceleration. Clutch issues?? It's always done that, it never seems to do it when a Ford tech is in with me. Also the towing issues are with only a very light laod in the back of the truck. I don't know, I just find it wierd that SUV's with V6's pull bigger trailer than I do.

Oh and yes rayaa86, last time I check it was a Ford. lol...

 

Something isn't right. I have the same engine and gears in my 08 Crew and just got back from a camping weekend where we took our 27 foot travel trailer. Not in the mountains mind you, but the hilly part of Southeastern Ohio. It weighs almost 5K (4500 dry and 800 lb tounge weight) loaded up and I was able to pass doing 70+ uphill. I know many who claim that the 4.6/3.55 is no good for towing, but I'm very pleased with the way it tows both my camper and our boat. Best part is that when not towing I'm getting better than 19 mpg. I think the fuel filter advise you are getting is correct, because you should have no trouble pulling 4K.

 

Your tires and wheels are probably hurting you. What size are they and have you any idea what they weigh?

Which trans, auto or manual?

 

Aren't those only something like 210hp engines back then?

Bigger then stock tires, smallest stock ratio gears, power robbing tranny, and a weak engine to begin with...

Nature of the beast.

 

I would have to agree that something ain't right. When my truck was stock (4.2 V6, 3.55LS,) it could tow decent loads that were 1 - 1.5K lbs more then yours with no problems. Maybe your trailer brakes are engaging in some way?

 

231hp @ 4750 RPM for the 2001 4.6

on 2000's and below it was rated @ 220 @ 4750 RPM

 

Thanks for all your suggestions, I'm glad I'm not the only one that thinks something is wrong. The tires btw are stock size, of course they are a bit heavier that the original stockers, but I think my wheels are lighter than stock so that sould babalnce out (I also have an auto tranny). I just had the brakes checked on the trailer and they are good, although I guess if my brake controller isn't set-up right maybe I have some drag.

I think I'll take her in to get things checked, I've been **** about maintinaing my truck so all fluid changes have been done regularily. I amy also take ouyt the performance tune, return it to stock and see what that does.

 

Performance tunes are rated for towing no more than 2500# on most tuners, unless you're using a "towing performance tune". I know Bill at PHP says running custom or even stock towing tunes when pulling over 2500 is recommended