this is going to be lenghty and maybe hard to follow but i really apriciate any info anyone has on this matter.

A thread on another forum sparked my interest so here we are, I want to know about the leaf springs on these trucks.

My truck, 97 4x4 off road, has four leaves in the packs, and so does my dads 02 Fx4. My grandpa has a 98 2x4, My girlfriend has a 2000 4x4, her dad has a 98 4x4, and her brother has a 97 4x4, and all of these trucks have 3 leaves in the packs.

The thread that started my interest was as follows, the OP has a 99 4x4 off road which he has had an add a leaf profesionally installed... (pack taken apart and put togeter with an extra leaf) and his dad has an 01 4x4 non off road and when pulling the same trailer, the second truck (with stock springs) performs better. (both trucks originally had 4 leaves in each pack)


could the difference from the 3 too 4 leaves be tow package, non tow package?

what is the difference in the f250ld spring pack? is it possible to swap a set to a regular f150?

also, why would the more stock truck, with more miles, perform better in the same situation?

thanks for any help you can give !

 

Got me stumped.
Not sure I'm following... You saying the OP's was a truck with 4 stock springs and he put an add a leaf on making it 5 springs.. vs. A truck with 4 stock springs? Springs have different ratings.... Just because it has more springs doesn't exactly make a difference, especially if the difference is only one spring. There are "overload" springs, not add a leafs, that are meant for towing. And it would be nice if he described what made the other truck tow better....

The truck that put the add a leaf on could have had worn springs and adding the add a leaf didn't help much with towing vs the other truck with not so worn/used springs. Making the truck with the add a leaf squat a little more, or be a little more washy while towing. Maybe he tows more than the other truck, wearing his springs out faster. I put add a leafs on my last f150 to help level my lift out, I don't think they made a whole lot of difference in how it towed or what it could haul. And that was on a truck that had never seen a trailer and was purchased from original owner.

 

both trucks started with 4 springs. the one with the add a leaf, was supposed to add 900 lbs worth of payload. .. . basically make the rear stiffer under load. the truck with the add a leaf has fewer miles, and easier miles than the stock truck. and what he said was better about the stock truck was just that it held the same exact trailer up better, and bounced less going down the road.

and i understand that springs can be rated differently, but why would two very simmilar f150s have the same number of springs, and have springs that were ratted differently? was there a difference in tow rattings between 99 and 01?

 

There are at least two ways to look at this.
The factory option for the peticular truck and the legal load permitted for the option.
Comment; you can add spring/load capacity but are you over loading the truck in actual use?
Trailer hitch loading may drop the rear too low and could use an extra leaf. In this event, I would use a torsion load leveler setup and keep the better ride for non towing use.
You need to keep in mind the reason for adding a spring as well as the extra stiffness you have when empty.
Over loading an F150 rear on a continious basis is pushing the life limit on the axle bearings vs the life of a heavier rear design.
Since there are no loading parameters given, this is just thoughts and considerations.
In other words you need a reason to do it and then keep within weight capacities.