When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I just bought a 22' travel trailer(4000lbs). Went to pick it up and on the way home was totally shocked, my I6 5spd. will not even attempt to do the job!! I looked up the towing capacity and I am not out of the limits? The motor only has about 10,000 miles on it and runs like a scalded dog when I'm not pulling. My only hope is that I can change the rear gear ratio from a 2.73 to something with more bottom end. Any help will be greatly appreciated.
I also recommend changing the gears. Those 2.73 gears are pretty much worthless. I would go with at least 3.08, if not 3.55. The I6 isn't a high reving motor so I wouldn't go any more than that unless it has large tires.
You shouldn't need to calibrate the speedometer unless you run larger tires. Gears only matter on the older vehicles. The speed sensor monitors axle revolutions, so tire size is really the only factor.
I do use the truck for some highway driving but I need to be able to pull my trailer. I know that most of the automatic trucks came with 3.73 gears so I don't know how I got the raw end of this deal. I hope to be able to find a whole rearend and just swap it out.
3.73's weren't available in 1996...I don't think they were earlier either. 2.73's were in F-150 regular cab, 5 speed, I6, 4x2's only. Probably a fuel economy thing. My brochure says this combo is not recommended for trailer towing.
3.55's are probably the most common. They should still get you decent mileage while getting you some more rpms for pulling.
3.73 gears are not a common setup. In fact I believe that 3.55 was the best factory option gear that Ford offered in F150s. The sucky 3.08 and 2.73 gears were common. My truck came with 3.08. Many of the I6 5 speed trucks came with 2.73. If you ask me the I6 trucks should have at least come with 3.08 and the V8 trucks 3.55.
Thanks for the input, I looked up the specs on an earlier model truck when I was searching and it came with the 3.73 ratio, I have found most of the used rear ends for sale are a 3.55 ratio. I think that I will try to find someone local to set up a new ring and pinion, for the price, versus buying a whole new rear end. Any input as far as first hand knowledge of having a truck with the I6 and this setup would be nice, I would hate to not put enough gear in it when I have it apart. Thanks
My previous truck was a 95 I6 auto with 3.08 and it did fine most of the time. 2.73 should not be used in anything especially with an overdrive transmission. You should be happy with 3.55. I would just find a used rear axle that already has 3.55 with limited slip and trade yours out for that. Then replace the bearings and wheel seals etc in it. You can do this and keep your brakes. You may be able to get a salvage yard to allow you to trade your rear axle and a few bucks for one of theirs.