Hello everyone. I have a few questions about the TTB front end. Truck info is in my sig. I've heard horror stories about shops not being able to do them and if they claim they can, it's normally not correct. Is there any way to accuratelly measure the caster at home without taking it to the shop? I'm pretty confident on measuring the camber and toe by myself. I've just replaced my ball joints and tie rod ends and one of my tires has some pretty bad positive camber. I plan on taking it down to get it aligned properly but I just want to make sure that they did it right and aren't jerking me around by just fixing the camber and not checking the caster. Also, does anyone know the factory specs on what caster and camber angle should be? What about toe, in-out-even? If so, how much? I guess my last resort would be to take it to the stealership but how would I know that they did it right. They also might not want to work on my truck because of the D50 install into the 150 setup. It is all leaf sprung though so they might. Thanks in advance!

 

Wow, i have never heard that. I have a 1979 ford f-100, and it has the ttb front suspension...just had that done with no problems

 

your 79 does not have TTB, it has TIB,
regardless, i did mine with a level. got it close with the offset camber bushings. They did not move it at the alignment shop.
I did drive for a few months with one wheel noticeably leaning, it surprisingly doesnt wear your tires near as bad as a toe in or toe out does.
mine was a D50 fwiw.

 

To get a TTB front axle aligned, and have it keep the alignment, make sure you check out the axle bushings also. There are bushings for the radius arms, and bushings where the TTB arms pivot. If any of these bushings are junk, the truck will not keep the alignment long. Once you make sure they are good and tight, also check the bearings, ball joints, tie rods, shocks/shock bushings, and steering box free play. All these parts must be good and tight for the shop to do the alignment and do it properly, where it will stay aligned. But these trucks are alignable, and if done properly will hold the alignment forever. After I went over my front axle, and replaced all worn out parts, the local community college was able to get my truck a perfect alignment and its got a 6" lift and 33x12.5" tires. Its definitely doable, but everything on the truck needs to be in good shape first.

 

I have been meaning to post this exact question, but whenever I'm at the computer it seemed to have slipped my mind. Excellent Info Blue. I've gone into shops before and asked them how they handled TTB axels on fords. The answer was always, "well, we align anything".

That was a total turn off and I walked out. To me, that's saying, I don't know what a TTB is and I don't know that it's different than anything else. Now that I read this, maybe I'm being over picky.

 

F150's are a bit more work than the F250's as well.

 

^^^ Not really. F150s have radius arms, but F250s have leaf spring/shackle bushings

 

yes really, how often do you have to change shackle bushings?
usually the springs are shot before it comes to that.
Every F150 i've owned (3) I had to do radius arm bushings.
i've only replaces spring bushings on a 250 once, and i replaced the whole worn out spring which came complete with bushings.
the 250 had about 350,000 on it when i did that. none of the F150's ever made it close to that many miles before bushings and springs were shot.

 

On my F250 the shackle bushings are shot, springs were fine. You should be replacing shackle bushings roughly the same as your replace radius arm bushings. they both wear out from the same root cause. Problem is most people dont know how to check shackle bushings for wear, and they never change them

 

theres a big difference in the surface area's absorbing the abuse.
and very different loads on said surfaces.

 

Thanks for all the good info. I did replace the axle pivot bushings about two months ago with new MOOG bushings. That was a bear of a job. My brackets that held the axle pivot bushings were loose also so they got tightened and welded to the frame. That won't happen again. lol. Ball joints and tie rod ends are new. The bearings are good so I repacked them and re-installed them. I do plan on changing them because of high mileage along with the front U-joints and also doing a once through on the front diff a little down the road but I was short on funds to do everything at once. The only thing that I didn't check was the leaf spring bushings. They look like they are pretty good and like little husky was saying, I would rather change out the springs than change the bushings in them. They are rusty and the pads between the ends of the springs are gone so they might not have too much life left in them. The only other thing in question then are the shocks/shock bushings. The PO neglected to hook these back up when he put the D50 under it. I don't see how they would change the outcome of the alignment as they carry no load and only dampen the bounce. Don't get me wrong, I do plan on hooking them back up (along with the front sway bar) for a more comfortable ride, but I need to get a set and fab up some upper mounts for them to attach to the frame (because the PO didn't put that on either).

I'm still curious about measuring the caster though. I had a rough idea, but I think that I would need the little ball bearing pads for the tires to sit on. Take a magnet and mount a laser to the hub dead level when the hub is straight and turn both wheels to full lock in both directions with the brakes depressed (so the wheels don't rotate) and trace the arc that it makes. Assuming that both wheels are at zero degrees on the camber, you should be able to work out the caster angle number with the information that you obtain. Not sure, what do you guys think? Anyone have any other ideas? Thanks!

 

Caster does not affect tire wear so I just adjust it to make the truck run straight down the road. Camber and toe are more critical IMO since they affect tire wear.

 

I understand that but wouldn't caster help in keeping the truck from pulling to one side or the other? I believe thats why when you let the wheel go in forward it goes relitively straight but when you try it in reverse the wheels quickly go to full lock either way that is easier. I just want it to track straight.

 

correct caster is what allows the wheel to return to center naturally. If your caster is off, the truck will have a tendency to wander. Also caster is what keeps the truck stable during high speed turns maneuvering. Ie quick lane change on the interstate