the TIB on my '80 f/150 is asymmetrical. the I-beam in the front is longer than the i beam in the rear.

anyone know why this might be? seems like a waste of money to cast 2 different beams & would throw the geometry out of wack.

 

Camber and Caster would not be correct if the beams were the same.

 

Steering geometry change is less effected by running equal length beams. In fact equal length is desirable. Beams that are not the same length will have different geometry changes from wheel to wheel throughout the suspension cycle.
Many fords ran equal length beams. In fact the equal length beam is one of the most desirable installs for long travel desert vehicles.
Fact is that un equal beams create a change in steering geometry from wheel to wheel.
Shorter side has more change but with limted travel is minimal.
Twin traction beam and stamped 4wd beams required a long arm short arm set up due to the driver side diff and two piece pass side axle. There was no longer any room for a long beam with a differential in the way.This was also when the ford plant responsible for creating the forged beams was shut down. The replacements were then cast and to keep costs to a minimum, ,they used a similar dimension as the 4wd vehicles. This kept steering components, radius arms, and crossmember mount similar. It was all about production.
The longer the beam the less impact it will have on steering geometry change. Shorter arms have less travel as well.

Here are equal length beams and a swing set steeering system. factory would not put this work into a production vehicle that was designed to have minimal travel, so inverted "Y" steering was just fine.



Little did ford engineers know that 40 years later this design is still the "hot ticket" among long travel high speed off road racers.

 

thx, very informative post.
i figured it had to do with production costs, like so many other *******izations of good ideas...

anyway, it's gotta go. i'm swapping to a straight axle from a '31 ford pick-up that'll let me have the drop or lift i'd like without the camber issues.

on that swing steering, do those blue brackets move with the steering? if so, thats pretty ingenious.

 

I might include the fact that Twin traction beam and twin I beam suspensions are two different animals. So we dont want to get confused. I assume that we are discussing a 2wd truck.
Interesting that you notice those little things. This pic is actually of a long travel set made from a 4wd TTB front end. See the ends? Those are 4wd beam ends that have been cut and then the equal length beams were fabricated and welded to the ends. I just sold a comlete front axle to a desert guy that makes these. Pretty cool reall, as I am new to the desert scene. Its not my cup of tea, but I appreciate all of the fantastic fabrication that these guys do. Ut is amazing, and I respect it and learn from it.
IN the above application, there is a pitman arm that has been modified to accept a short drag link. That is help in double sheer, and is short enough to maintian the proer geometry that still provides a lock to lock steering movement.
OK that little drag link pushes or pulls at the small link located on the driver side frame rail. This pivot is connected to another pivot on the opposite side of the truck.
Each pivot is connected to the steering knuckle on the opposite side of the truck and one link connects the two pivots. By having two pivots hanging off of the frame sides, and connecting to the opposite knuckle, the steering links can have the identical arch of motion that the beam does. This prevents bumpsteer, which is a killer when these things are traveling as fast as they are given the rough terrain.
It looks a little goofy, only because we are not used to seeing this stuff, at least I was not, but this "swing set" or double swing is very common in the desert world.
Very effective and very functional.
Obviously too many moving parts for a production type vehicle that was not intended to have double digit travel numbers. Travel in excess of 17 to 24 inches is not uncommon for these typical vehicles. cool stuff.
Should see how these guys are getting these numbers from TTB 4wd front ends. Awesome and spendy.

 

Im wanting to do a long-travel set up on the front of my 2wd 75 f150. does anyone know if there was a difference between a 2wd 75 front suspension and a 2wd 80 front suspension?

 

75 had the steering behind the axle, 80 and up had the steering in front of the axle. Beams are different lengths, the 80 and up was wider.

 

First Welcome to FTE!

you might want to check out Autofab and look at the kits they offer for sale. i'm going with the 5 inch lift on my 65.... if i ever have the funds.

wheel travel early ford

 

I found a long travel kit for 80 and up f150's, and im tryin to see if it will work for my 75, and if not if changes can be made to make it work.

My other thought is, would putting long travel shocks and springs on otherwise stock suspension give me an increase in travel or will the stock parts limit me.

By the way Bill, my brother asks if you got the gauge in your 66?

 

Your Joel's Brother! he must have a job now... he is never on the forums anymore. Tell him i said Hello.

Yes i put it in the dash with a new sender, it works good

 

Yep, I'm joels little brother with the green 75 out at that property. He did get a job which is good and still has that 240 and tranny. He says Hey

 

ya sorry Bill, workin like a dog! But I'll be resurrecting the truck soon hopefully! considering saving up to do the power disc upgrade.

 

Joel, My neighbor has a truck he is parting and it has spindles disc's and calipers, i think i could get them for 50 bucks. let me know.

 

Im gonna say yes for him..

 

If it can work out, I'm heading down to near your house this weekend., and i could pick that up for him..