I have a 1999 f150 4x4 supercab 4.6 auto. I have just purchased. I find this truck is sluggish pulley my 16' hay trailer up hills,. I have to pull it into to 2nd gear, I had a 4.0 litre Ranger before this, and it hauled the trailer easier. Any Ideas!!

 

Could be a number of things. The gear ratio could be different from what was in your Ranger, as well as the transmission ratios. That could make your old Ranger feel more powerful. The 99 4.6L's had around 220 or 225hp. What gear ratio does your new truck have? How many miles is on your new truck? If you have higher miles you might want to try a tune up.

 

Truck has 60,000 klm. gear ratio is 3.55 and I had tried tune up but no diff.

 

I have a 98 4.6 Auto w/ 3.55 LS and a 99 SC Auto w/ 3.55 LS that are both used to tow 28 ft. hay trailers. Both have over 100K miles and get similar mileage loaded and unloaded. Unloaded the 4.6 performs close to the 5.4 (I guess it is the weight difference that makes them close). Loaded the 4.6 strains and takes longer to get up to speed. Both have K&N air filters, free flowing mufflers, run Mobil1 Oil, and are serviced on a regular basis. I have had a few minor issues with both but they are able to do the job.

The 4.6 is getting close to 200K and is showing it's age (I purchased both used). I plan to replace it with a diesel within the next year (I prefer Ford but I am not sure about the 6.0L Diesel - I will make that decision later).

If you have oversize tires this will affect your final drive ratio. Being 4x4 and SC both add a lot of weight to the truck. The 4.6 is a good engine but it is a little underpowered for a work truck. You may consider new gears to make it more acceptable (I have considered this many times).

 

The 4.6 needs to rev to really get into it's powerband. With 3.55 gears, it would not be unusual for it to shift into 2nd. What was the grade of the hill?? How much weight are you talking about? What speed are you going when you start the pull??

I know hay is basically "light", but I've bucked enough of the stuff to know them bales do get heavy....

If you do have larger then stock tires on it, then that will reduce the ratio even more as spray mentioned.

Comparing to your Ranger, well, the Ranger is going to be lighter and probably has at least 3.73 gears, if not 4.10's in it. Manual or auto?

I bog down pretty good with my #4500 travel trailer going up 6% grades if the speed limit is only 35 mph or so...... At highway speeds, I can get more of a run on it and keep the engine in it's power band easier then having to start the pull doing only 40 mph or so...... I can easily maintain 55 mph on 6% grades, as long as I can keep the revs up......

Good luck!

Mitch