Camber on 4WD trucks

[Pete Whitstone]

Hi All,

I'm in the middle of swapping my 81's 2WD suspension for that of a 95 4WD setup from a donor truck. The back is all done and I'm working on the front. I have the 4WD suspension arms in place now. I am using the springs from the 4WD truck.

When I assemble the front suspension to the point where the ball joint/brake system carrier hub is placed on the truck, and then I put a jack under it and jack it up to the point where it is lifting the truck off the jackstands, then the springs have compressed to ride height. However, when I place an angle meter on the carrier hub, it shows about 4.5 degrees positive camber for the drivers side, and about 4 degrees for the passenger side.

If I'm not mistaken, the biggest camber adjuster you can buy comes in with around 2.7 degrees of camber adjustment. So basically I can't adjust camber enough to achieve a "normal" negative camber situation.

Since camber on this truck is basically a radius from the suspension arm mounting point, the arm would need to pivot a whole lot more upwards to achieve zero or negative camber. I thought maybe the taller springs from the 4WD were working against me, so I swapped the 2WD spring back in to see what difference it made. The 2WD spring was only an inch or two shorter, and was not enough to counter the absurd amounts of positive camber. Basically to achieve zero camber, the spring would have to be much much shorter, but then the ride height would be all wrong.

So the thought occurred to me that maybe these trucks typically run positive camber, and this was all normal. That doesn't seem right to me, but I've never had a 4WD truck of any vintage, let alone an early 80's (ok maybe a mid-90's depending on which truck we are talking about).

Any thoughts on whether positive caster is normal? If it's not, I don't see how zero or negative camber can be obtained from here. The small amount of adjustability at the top ball joint is never going to be enough, and everything else is "hardwired" and is not going to change without cutting and welding, as far as I can see. Help!

Thanks,

Pete

[Gary Lewis]

The spec's are in the factory shop manual section at Documentation/Suspension & Steering/Alignment. Scroll down to the bottom of Page 6 and you'll see the info on the 4x4 F250 & 350 in the lower right.

But there are several things to tell you. First, this is from the 1985 FSM and I suspect the info is for TTB rather than a solid axle. And I'm not sure how to figure that out. However, I have a '95 FSM that I will check tomorrow and see what it says, and I know it is for a solid axle.

Second, while the camber angle is shown from -1 to +3, that depends on the angle of the frame. So don't miss this verbiage on Page 5:

Alignment caster of F-250-F-350 (4x4) is adjustable. Alignment equipment indicates a true reading only when the frame is horizontal, front to rear. Measure left and right hand caster angles as shown in Fig.6. If the frame is not level (due to tire, spring or load differences), the caster angle reading must be modified to compensate for the above frame angles. If the front is higher than the rear, subtract the amount of the frame angle from the caster reading. If the front is lower than the rear, add the angle.

Oh, wait! The axle in Big Blue is a '95 D60 and I had it aligned. Here's a pic of the spec's they were working to, but I think I found later those spec's weren't quite right. Let me check the '95 FSM tomorrow.

[Pete Whitstone]

The spec's are in the factory shop manual section at Documentation/Suspension & Steering/Alignment. Scroll down to the bottom of Page 6 and you'll see the info on the 4x4 F250 & 350 in the lower right.

But there are several things to tell you. First, this is from the 1985 FSM and I suspect the info is for TTB rather than a solid axle. And I'm not sure how to figure that out. However, I have a '95 FSM that I will check tomorrow and see what it says, and I know it is for a solid axle.

Second, while the camber angle is shown from -1 to +3, that depends on the angle of the frame. So don't miss this verbiage on Page 5:

Alignment caster of F-250-F-350 (4x4) is adjustable. Alignment equipment indicates a true reading only when the frame is horizontal, front to rear. Measure left and right hand caster angles as shown in Fig.6. If the frame is not level (due to tire, spring or load differences), the caster angle reading must be modified to compensate for the above frame angles. If the front is higher than the rear, subtract the amount of the frame angle from the caster reading. If the front is lower than the rear, add the angle.

Oh, wait! The axle in Big Blue is a '95 D60 and I had it aligned. Here's a pic of the spec's they were working to, but I think I found later those spec's weren't quite right. Let me check the '95 FSM tomorrow.

Gary, to be clear, this is a F150 (in both cases, the 81 I'm working on and the 95 donor vehicle) and both have the TTB suspension. No solid axles going on here, or any Dana larger than the 44.

[Gary Lewis]

Gary, to be clear, this is a F150 (in both cases, the 81 I'm working on and the 95 donor vehicle) and both have the TTB suspension. No solid axles going on here, or any Dana larger than the 44.

My bad. Sorry. But see if this section from the '95 FSM helps:

 

[Pete Whitstone]

My bad. Sorry. But see if this section from the '95 FSM helps:

 

Thanks Gary. I have both the 81 and 95 body/chassis manual, so I'm not unequipped in the way of documentation. But I haven't seen anything in the documentation that addresses a large amount of positive camber that seems to be built into the suspension arm. That's where I'm still stumped.One way to get the camber more towards zero/negative would be to drop the suspension arm mounting point. But the donor 4wd truck seems to have the same suspension arm mounting point as the 2wd one, as far as I can tell. Anyone know any different about that?While shopping for camber adjusters, I saw some reference to "you can use this in the lower ball joint as well, to gain even more caster/camber adjustment". But I'm thinking that must have applied to some other truck than an F150. There does not seem to be the same "pop-out" arrangement on the lower ball joint taper that there is on the upper ball joint taper. As far as I can tell, the lower ball joint taper is machined into the suspension arm itself, and it does not change/move. Am I correct about that?Thanks!

[Gary Lewis]

Thanks Gary. I have both the 81 and 95 body/chassis manual, so I'm not unequipped in the way of documentation. But I haven't seen anything in the documentation that addresses a large amount of positive camber that seems to be built into the suspension arm. That's where I'm still stumped.

One way to get the camber more towards zero/negative would be to drop the suspension arm mounting point. But the donor 4wd truck seems to have the same suspension arm mounting point as the 2wd one, as far as I can tell. Anyone know any different about that?

While shopping for camber adjusters, I saw some reference to "you can use this in the lower ball joint as well, to gain even more caster/camber adjustment". But I'm thinking that must have applied to some other truck than an F150. There does not seem to be the same "pop-out" arrangement on the lower ball joint taper that there is on the upper ball joint taper. As far as I can tell, the lower ball joint taper is machined into the suspension arm itself, and it does not change/move. Am I correct about that?

Thanks!

Is the frame in the position it will be when all this is done? As the '85 manual says, you have to add/subtract the angle of the frame from the camber recommendation. But I'm sure you know that.

As for the lower ball joint, I don't see how you could get an bushing in there. The ball joint's stem was made to fit directly into the knuckle.

I wonder what Shaun/salans7 knows about this. Maybe there's something different about the frames? I'm going to tag him.

[Pete Whitstone]

Is the frame in the position it will be when all this is done? As the '85 manual says, you have to add/subtract the angle of the frame from the camber recommendation. But I'm sure you know that.

As for the lower ball joint, I don't see how you could get an bushing in there. The ball joint's stem was made to fit directly into the knuckle.

I wonder what Shaun/salans7 knows about this. Maybe there's something different about the frames? I'm going to tag him.

It's pretty close to it's final position. The truck is sitting on the rear wheels, and is pretty level both side to side and front to back. It's sitting on jackstands positioned on the frame just behind the radius arms.

When I measure the camber, I put a jack under both suspension arms and raise them til the frame just barely rises off the jackstands. So the front may be an inch or two higher than it would be when it was actually sitting on the wheels, but I can't see how that would affect a camber reading by any significant amount. Caster, sure.

Can you point me to the specific verbiage about the frame angle?

[Gary Lewis]

It's pretty close to it's final position. The truck is sitting on the rear wheels, and is pretty level both side to side and front to back. It's sitting on jackstands positioned on the frame just behind the radius arms.

When I measure the camber, I put a jack under both suspension arms and raise them til the frame just barely rises off the jackstands. So the front may be an inch or two higher than it would be when it was actually sitting on the wheels, but I can't see how that would affect a camber reading by any significant amount. Caster, sure.

Can you point me to the specific verbiage about the frame angle?

I think you are checking it the same way I would. And I don't know what else to say or do.

[Pete Whitstone]

I think you are checking it the same way I would. And I don't know what else to say or do.

Maybe some pictures will show something. At this point I'm starting to think I have the ball joints installed backwards, upside down and on the wrong side or something. Here is the driver side. Anything out of place?

I'm not sure if those little sway sway bar end links are supposed to rise up from, or dangle down from, the sway bar itself. I couldn't find any decent pictures or diagrams.

I made a tool and pulled out the old top ball joint tapers, and installed the adjustable ones. I installed them for maximum negative camber. On the drivers side, this was able to achieve a roughly zero camber situation at ride height. I'll take that for now.

On the passenger side, not so much. The taper that was in there was already adjusted for max negative camber, so putting the new one in and setting it for max negative camber reduced it from around 4 to slightly more than 3 degrees positive camber. Still way too much, but I'm tempted to put it all back together again, drive it some, and see if it doesn't settle into a more straight-up position.

I did check the "frame angle", I am assuming this means the side-to-side lean of the truck, and not any fore/aft difference (one end sitting higher than the other). I'm not really sure where to check this. The trans crossmember seems to have a part on each end that appears to go pretty much straight across, so I stuck the angle finder on it with both front arms jacked up to where the truck frame just comes off the jackstands.

Seems pretty level to me.

So unless someone can spot that I've assembled something incorrectly, I guess I'm going to proceed with putting the rest of the suspension and wheel stuff together. Starting with the driver side.

Sorry for the sideways images. They are upright on my computer. Stupid iPhone.

 

[Gary Lewis]

Maybe some pictures will show something. At this point I'm starting to think I have the ball joints installed backwards, upside down and on the wrong side or something. Here is the driver side. Anything out of place?

I'm not sure if those little sway sway bar end links are supposed to rise up from, or dangle down from, the sway bar itself. I couldn't find any decent pictures or diagrams.

I made a tool and pulled out the old top ball joint tapers, and installed the adjustable ones. I installed them for maximum negative camber. On the drivers side, this was able to achieve a roughly zero camber situation at ride height. I'll take that for now.

On the passenger side, not so much. The taper that was in there was already adjusted for max negative camber, so putting the new one in and setting it for max negative camber reduced it from around 4 to slightly more than 3 degrees positive camber. Still way too much, but I'm tempted to put it all back together again, drive it some, and see if it doesn't settle into a more straight-up position.

I did check the "frame angle", I am assuming this means the side-to-side lean of the truck, and not any fore/aft difference (one end sitting higher than the other). I'm not really sure where to check this. The trans crossmember seems to have a part on each end that appears to go pretty much straight across, so I stuck the angle finder on it with both front arms jacked up to where the truck frame just comes off the jackstands.

Seems pretty level to me.

So unless someone can spot that I've assembled something incorrectly, I guess I'm going to proceed with putting the rest of the suspension and wheel stuff together. Starting with the driver side.

Sorry for the sideways images. They are upright on my computer. Stupid iPhone.

Here's a shot of the sway bar mocked up on Dad's truck. But I don't know if the '95 bar is the same.

And here's your knuckle compared to the one on Dad's truck. I don't see anything wrong. And I think I'd put it together and see what happens.

But the issue on the image rotation is not the iPhone. It is doing its job and embedding the orientation in the metadata of the file. But our forum doesn't read that data. So if you rotate the phone to take a pic then you have to rotate the pic to post it. I use Photoshop Express, but there are free packages for phone that will do it.