front end alignment question

[laserjock]

Guys,

I think I may tackle the front end of the truck first with a once over (new universals, calipers, fluid, seals, etc.). I noticed the other day that the truck seems to have worn the outsides of the front tires. In my little brain that says a camber problem exists. The 91 F250 seems to be a solid front axle truck with what I believe are ball joints rather than king pins. Outside of tow in/out by adjusting the tierods, is there a camber adjustment or are the ball joints just shot? I've never worked on a solid axle with ball joints so this is a new one on me.

Thanks!

 

[franklin2]

The 91 f250 did not come with a solid axle from the factory, so someone must have swapped it in.

Regardless of what it has, ttb or solid, they are both aligned by eccentric bushings that the top balljoints sit in. The top ball joints are not pressed into the axle housing, they are pressed into bushings that can be turned to bring it in. You can also buy different bushings with different amounts of adjustment made into them. But they have their limitations, and that's why these trucks(with the ttb) are so sensitive to ride height as far as their alignment is concerned.

 

[laserjock]

Okay. Clearly I'm not sure of the difference. What does ttb stand for?

Here is the only shot I have of it. What you describe makes sense looking at this picture.

You must be registered for see images attach

. It may not have attached. Anyway, the crux of the matter is that yes there is an alignment mechanism.

Thanks!

 

[Bashby]

attachment did not work. TTB stands for twin traction beam, the type of suspension on the front of your F250 from the factory. F350's came with a solid front axle.

 

[laserjock]

Here it is again. Not sure how to attach pics from the phone. I think this worked.

 

[RLDSL]

To put it in laymans terms, take it to a 4x4 specialty allignment shop. Do some digging around and find teh place in your area that does all the work on the trucks that have the silly high lift kits and tractor sized tires on them, this will be the place that has the experience to properly install the correct bushings and set them on yyour truck, if you go to a plain ol tire shop, you will likely get some kid who gets confused with anything bigger than a toyota.
I have to take my truck to a place that works on semis because it's too stinking heavy for the rack at the place that works on the big pickups

 

[lotzagoodstuff]

The picture isn't definite, but I think you have a TTB Dana 50, which would be the original axle under your F250. Any chance anybody has put an add-a-leaf or newer fronts springs in your truck? I had a sagging front end and put an add-a-leaf and it wore the outsides of the front tires until I adjusted the camber with the offset bushings. Google offset bushings and look for a video to explain it, but in laymans terms, the outside of your tires are wearing because the top of your axle knuckles need to be moved more "inboard" with an offset upper bushing. If you have new leafs installed, your camber will end up needing to be adjusted. Once you see the offset bushing, you'll understand how it works. You can put a straight edge accross your rims and use a magnetic pointer level to see where you are now on flat ground, and I'm guessing you'll see that your camber is too positive, which is causing your outer tires to wear.

 

[bike-maker]

The way the geometry of the TTB works, excessive toe in will actually make the front end ride higher and wear the hell out of the outside of the tires.
Learned that after my first failed attempt at aligning the front end myself.

 

[Bashby]

The way the geometry of the TTB works, excessive toe in will actually make the front end ride higher and wear the hell out of the outside of the tires.
Learned that after my first failed attempt at aligning the front end myself.

I'll confirm that toe in will wear the outer edge. Really the best thing is to have it aligned professionally. Be ready to pay extra if you need camber adjustments.

 

[laserjock]

Thanks for the info. The toe thing makes complete sense. As high as the truck sits, I wouldn't be surprised if its had an extra leaf. It's got 285's on it and there is plenty of wheel well. Can anyone tell me how many it is supposed to have front and rear? It's got quite a stack in the back with what looks like an overload type arrangement. It does have the door tag that says it is equiped with the ambulance package if that makes a difference.

 

[bike-maker]

Should be 2 leafs per side on the front.

 

[laserjock]

Does that count the leaf that is attached to the spring shackles? If so I can see at least 3 in the picture of the ball joints. That may be the problem then. It does have a plow bracket on the front and plow but the really don't look like they've been used much on this truck.

 

[zebrabeefj40]

If the pic you posted is of your truck there are at least 3 pieces of leaf that are extra on the bottom of the leaf pack. The overload stuff on the rear is likely stock. The 3 long leaves in the front look stock to me - I have an '89 here now that has the same 3 leaves in front. The '92 in my sig has 2 leaves in front.

FWIW I have had my truck with TTB aligned at Sears in the past and they did ok with it. Stupid expensive to install different alignment bushings but otherwise did good work.

Nick

 

[laserjock]

That is my truck. So it looks like there may be a redneck lift kit on it. I thought that looked funny. That would probably be enough to cause the tire wear problem don't you think? It may have the same under the rear. I'll look when I get home tonight if I make it before dark.

 

[laserjock]

Had a look tonight. There are what looks like 2" blocks under the rear and a couple leafs that don't look like the others. Under the front, there are actually four progressively longer spacers with three long springs on top. I would guess maybe a block with a front leveling kit? Thinking on this, the change in ride height is coming from spacers above the axle. The only other attachment is the shocks and steering arm right? I'm not sure I follow how that could change the camber. The only thing different as far as the axle can tell is the tire height. What am I missing?