Alignment Issue After Disc Brake Upgrade?

banjopicker66 · Post by **banjopicker66** » May 25, 2009, 7:58 pm

All: I just finished upgrading to disc brakes - and it stops really sweet. However, it needs an alignment yet.
It drives OK to about 25, but then it starts wandering badly - but that will get fixed - I hope - with the alignment.

But I am worried, and the picture should explain it. It looks like camber is WAY out.
With the original drum brakes, the alignment was perfect, and stayed that way for many years.
I did not change the I-beams, nor did I take them off, but drove out the king pins on the truck, and changed the spindles, tie rods, and brake system.

If I understand it, the toe should be all that needs correcting - but the pictures seem to show a camber problem. Any discussion on this, the cause and the cure will be highly appreciated.
Or, is this an optical illusion?

[albumimg]5859[/albumimg]

ezernut9mm · Post by **ezernut9mm** » May 25, 2009, 8:01 pm

pic doesn't work.

ezernut9mm · Post by **ezernut9mm** » May 25, 2009, 8:04 pm

from the pic in your gallery it seems to have quite a bit of negative camber. that alone shouldn't cause the wandering. could be toe in, or bad kingpins. i know that if the toe is out it will wander some.

banjopicker66 · Post by **banjopicker66** » May 25, 2009, 8:04 pm

I can't get the picture to display. It is in my album, though.

banjopicker66 · Post by **banjopicker66** » May 25, 2009, 8:06 pm

Thanks - but I am not concerned about the wandering yet - I am concerned about the camber.
There was no camber before I changed the spindles with new kingpins and nice tight bushings.
Did I read you correctly, that incorrect toe will cause incorrect camber?

ezernut9mm · Post by **ezernut9mm** » May 25, 2009, 8:09 pm

camber and toe are not related as far as i know. they are independent adjustments.
what year did the discs come from? there are different sized king pins and bushings. i'm not sure on the years and changes, but there are two different sizes for the disc front ends.

banjopicker66 · Post by **banjopicker66** » May 25, 2009, 8:12 pm

The disc spindles are from a '76 F-150. The king pins are for a '66 - but everything lines up there. The '66 king pins are slightly different in that they are about 1/8 of an inch shorter total, but the banjo bolt lines up, leaving them 1/16th shorter top and bottom.
'you have to use '65 king pins on '65 axles, as the slot for the wedge banjo bolt is located differently.

ezernut9mm · Post by **ezernut9mm** » May 25, 2009, 8:53 pm

i think it was 77.5 to 79 that had a different diameter. if you didn't change anything but the kingpins i would say it was those that are causing the camber issue and could be the source of the wandering too. if nothing else was changed i don't see any other reasons.

oldtrucks · Post by **oldtrucks** » May 25, 2009, 9:41 pm

It looks like to me that the spindles aren't the same camber angle as your original ones. Is it possible you installed them incorrectly??? I haven't done any front end work for a long time and can't remember if it is even possible to install them incorrectly. Just a thought.

Bills 66 · Post by **Bills 66** » May 25, 2009, 10:26 pm

Banjo
I just went and looked at a set of 76 "I" beams that are not installed and my 65. It is hard to compare but it appears there my be a difference in the angle of the king pin between the two. Do you have the 76 "i" beams? I could try to mock up the 76 and get a angle reading of the king pin but I don't know how accurate it would be with out actually installing it.
Bill

66fordtrucknut · Post by **66fordtrucknut** » May 26, 2009, 5:35 am

I kinda remember the same thing Bill when I swapped my frontend. but I swapped everything, beams, radius arms etc. I even think there was a small difference in the spring hieght. It's been a while though.
Charlie

6166 Junkyard Dog · Post by **6166 Junkyard Dog** » May 26, 2009, 6:23 am

Banjo did you change the tie rods ? you know the spindles are thicker where the tie rods go for the 73-79 as oppose to the 65-72 trucks so either you have to use 73-79 rods or shave about 3/8 off where the rods go and also make sure all joints that the nut is very tight with no play , I know when we sell a kit it has the king pins with it for what ever year since shipping, if not doing it hear take I-Beams and radius arms buy all new rods, and when the old rods are on the ground match everything up pretty close with new ones at least to see how close before going to front end shop

banjopicker66 · Post by **banjopicker66** » May 26, 2009, 8:03 am

Tom, yes I did change the tie rods to the '76 type, instead of shaving the spindles.
It has all new steering linkage now, from the pitman arm to the steering knuckles.
If the toe is badly out, will that make the camber be out too?
Check the picture out in the first post - I finally got it to work.

6166 Junkyard Dog · Post by **6166 Junkyard Dog** » May 26, 2009, 8:10 am

ok BANJO Just making suree where on the right page

banjopicker66 · Post by **banjopicker66** » May 26, 2009, 9:38 am

Thanks for jumping in, Tom!
By the way, here are the I-beam casting numbers. I don't know if this will reveal anything or not:
Passenger side: C5TA-8-B
Drivers side: C5TA-9-B
My truck is most definitely a '66, not a '65, but would these I-beams be the cause?

Jonas · Post by **Jonas** » May 26, 2009, 10:23 pm

I think once you get the toe in adjusted you are going to be alright. Why don't you just adjust it as close as you can with a tape measure. At least you could see if it would straighten things up, before paying for an alignment.

You probably know this but.
Turn the wheels straight

Get a good reference point on back of the front tires halfway up. You can use a tread. Or clamp a board to the tires. Measure the distance between the rear of the two front tires.

Then get a measurement halfway up on the front of the front tires. measure the distance between the front of the two front tires.

I cannot remember right off hand. But I think it should be 5/16" toe in. I just checked this on my 65 when I put disc on it a few months ago.

I have done this swap a few times. Some ibeams, some just spindles. I remember doing my brothers 66(just spindles). It looked alot like your picture, until we adjsuted the toe in.

cdherman · Post by **cdherman** » May 26, 2009, 10:45 pm

I am nearly 100% certain that the 76 spindles should be fine and are not the cause of you problems. I used 78, but aside from that, I did all the same things as you.

I bet adjusting the toe-in will make the negative camber look less bad. But its possible your springs are getting old as well.

banjopicker66 · Post by **banjopicker66** » May 27, 2009, 9:18 am

You were correct - Once the toe-in was corrected, the camber problem was solved.
The excessive toe made the wheels assume the cant they traverse while turning. Since both wheels were turning out, they canted with negative camber on each side.