I Found the Magic Button!

[jjzepplin]

Did you mean "Castor" is as positive as it can be?

[shortbed70]

Alrighty I’m going to see what I can do Tuesday.

[BMERDOC]

Yeah. Caster needs to be as positive as possible.

[2500HD]

I just completed a steering rebuild (rag joint, pitman, idler, ball joints, tie rods, upper and lower control arms, Red Head quick ratio box, pump, wheel bearings and tires) and had the truck aligned. i now have a lazy return to center and while driving straight it seems kind of twitchy. I have a lot of caster so i dont understand the lazy return to center. Is the toe supposed to be toe in or out?

[2500HD]

..

[BMERDOC]

Going down the sheet in order, I would like to see a bit more camber. -.25° would make me happier but if you can't get there you can't get there. I question the frame angle. If its really 2° thats fine but if its closer to 0 (mine was 0) then your caster angle numbers are going to be off by the sum off the difference. Since its front steer it needs toe out. I would rather see 1/8" total (1/16 per side).

[BMERDOC]

I think I need to expand on that a bit more. Your toe and camber angles are a bit on the neutral side which would cause those angles to flip back and forth between positve and negative. You've gotta push them a tick more to make them stay in the range they need to be in. Confirm that frame angle was actually measured and not guessed at to confirm caster.

[Steeveedee]

Originally Posted by BMERDOC

Going down the sheet in order, I would like to see a bit more camber. -.25° would make me happier but if you can't get there you can't get there. I question the frame angle. If its really 2° thats fine but if its closer to 0 (mine was 0) then your caster angle numbers are going to be off by the sum off the difference. Since its front steer it needs toe out. I would rather see 1/8" total (1/16 per side).

Isn't it toe in for RWD?

As for the lazy return, how is steering force when you turn the wheel away from center? Could just be the box sector lash adjustment is too tight.

[BMERDOC]

Originally Posted by Steeveedee

Isn't it toe in for RWD?

As for the lazy return, how is steering force when you turn the wheel away from center? Could just be the box sector lash adjustment is too tight.

Its more about front vs. rear steer (in relation to the front cross member) but for the sake of packaging you can assume most FWD will be rear steer therefore requiring toe in. Its all about keeping the steering linkage taut.

[2500HD]

Originally Posted by BMERDOC

I think I need to expand on that a bit more. Your toe and camber angles are a bit on the neutral side which would cause those angles to flip back and forth between positve and negative. You've gotta push them a tick more to make them stay in the range they need to be in. Confirm that frame angle was actually measured and not guessed at to confirm caster.

Not sure about the frame angle. it does have a pretty good rake to it if that is what is meant.

Just so i understand, if the caster is 5.9 and the frame angle is 2 then my actual caster us 3.9?

I need .5 more camber (top of tire in / \) and 1/32 more toe on each side (front of tire out \ /) and as much caster as possible?

[2500HD]

Originally Posted by Steeveedee

Isn't it toe in for RWD?

As for the lazy return, how is steering force when you turn the wheel away from center? Could just be the box sector lash adjustment is too tight.

Steering force away from center is not hard at all but it does have a new Red Head quick ratio box that makes it a little stiffer. Not stiff but not pinky steer as it was before. I cant change the box for as the paperwork clearly says it is adjusted perfectly and it will void my warranty.

[BMERDOC]

I would verify frame angle or at least ask the guy that aligned it. Your math is correct...sorta. If your frame angle is 0 and they plugged in 2* the printout would say 5.9* when its actually 3.9*.
-.5 camber is good (tops of the ties pointing in). 1/16 toe per side (1/8" total) for toe.

[zicc1835]

funny I had my tires mounted and balanced yesterday at the shop i will have do my alignment at some point I discussed doing the alignment one of the mechanics there is ready to retire he and I went to the same school he is old school but is up to date with the newer technology this is going to be very helpful for me thanks so much for the info i gotta try to get it all together before he heads south

[Steeveedee]

Originally Posted by 2500HD

Steering force away from center is not hard at all but it does have a new Red Head quick ratio box that makes it a little stiffer. Not stiff but not pinky steer as it was before. I cant change the box for as the paperwork clearly says it is adjusted perfectly and it will void my warranty.

IMO, if the lazy return to center doesn't go away within the warranty period, I'd be talking to the builder...before the warranty is up. A billion+ vehicles have not had this problem,when new. I think that something is wrong with it. The paperwork saying that it is "adjusted perfectly" is just that, paperwork. I hope that the steering starts returning to center normally.

[MySons68C20]

Originally Posted by 2500HD

Steering force away from center is not hard at all but it does have a new Red Head quick ratio box that makes it a little stiffer. Not stiff but not pinky steer as it was before. I cant change the box for as the paperwork clearly says it is adjusted perfectly and it will void my warranty.

Did you ever get the return to center figured out? I'm having the same problem with the 68 with all new parts including a quick ratio Red Head steering box. I'm going to get my 2nd alignment at a different shop next week and want to be ready.
The first shop wouldn't/didn't give me numbers. The only thing I see is 1 1/8" shim on the pass side and a 1/16" shim on the driver side.

[Robznob11]

Originally Posted by MySons68C20

Did you ever get the return to center figured out? I'm having the same problem with the 68 with all new parts including a quick ratio Red Head steering box. I'm going to get my 2nd alignment at a different shop next week and want to be ready.
The first shop wouldn't/didn't give me numbers. The only thing I see is 1 1/8" shim on the pass side and a 1/16" shim on the driver side.

The return to center could be the lack of positive caster and not the box, you can trust very few alignment shops with these trucks, they dont want to take the time to unbolt add shims, tq it back up, and repeat several times getting it perfect. They usually take one stab at it and say ahhh it's good enough, many just set toe and take your money....I can tell you because I do my own alignments....it takes several hours to dial one in. Every time you Jack it up you have to reload the suspension (move the vehicle) or you will get a false reading.

[2500HD]

Originally Posted by MySons68C20

Did you ever get the return to center figured out? I'm having the same problem with the 68 with all new parts including a quick ratio Red Head steering box. I'm going to get my 2nd alignment at a different shop next week and want to be ready.
The first shop wouldn't/didn't give me numbers. The only thing I see is 1 1/8" shim on the pass side and a 1/16" shim on the driver side.

No not really. i had the same guy do the alignment again. and it is better but not great. it starts to return to center and then stops about half way back. i think i need more camber to get the tires more straight up and down. i have minimal shims in the front and none in the rear. Please let us know if you get it figured out. i will not be working on the front for some time. i currently have the rear out for rear control arm bushings, Eaton posi and 3:73 gear.

[Rooster73]

it ,kills me when someone comes in and hands me a sheet for the factory specs on an old ride. biasply then and radial now. 3 degrees positve was alot with biasply, these trucks with radials want at least 4 to 4.5 pos. setting camber and caster is no big time deal. all aligners the last 10 years use live caster readings and can compensate for elevated readings. i always rerun caster swing after adjusting, just a double check. rear shims effect caster more, front shims effect camber more, keeping less than a 1 degree split, more caster on right.any change in ride hieght changes all. there are so many measurements that effect how it drives, SAI, setback, thrustangle, along with camber, caster and toe.even a 20 thousand dollar Hunter aligner ends with a wrench and a brain. sorry for the rant, but after 30 years of frontend work i hear to many techs say set the toe and let it go. they should be sweeping floors.

[MySons68C20]

The only shims are in the front.....none in the rear at all. I have an appt on Wednesday and we shall see. The good thing is the guy said it may take him a couple hours to get it done. I like the fact he's willing to take the time to do it right and give me the dang print out!

[hjewell2]

subd

[jjzepplin]

Originally Posted by Rooster73

it ,kills me when someone comes in and hands me a sheet for the factory specs on an old ride. biasply then and radial now. 3 degrees positve was alot with biasply, these trucks with radials want at least 4 to 4.5 pos. setting camber and caster is no big time deal. all aligners the last 10 years use live caster readings and can compensate for elevated readings. i always rerun caster swing after adjusting, just a double check. rear shims effect caster more, front shims effect camber more, keeping less than a 1 degree split, more caster on right.any change in ride hieght changes all. there are so many measurements that effect how it drives, SAI, setback, thrustangle, along with camber, caster and toe.even a 20 thousand dollar Hunter aligner ends with a wrench and a brain. sorry for the rant, but after 30 years of frontend work i hear to many techs say set the toe and let it go. they should be sweeping floors.

Thank you! Can I bring my truck to you for an alignment?

[MySons68C20]

Originally Posted by 2500HD

No not really. i had the same guy do the alignment again. and it is better but not great. it starts to return to center and then stops about half way back. i think i need more camber to get the tires more straight up and down. i have minimal shims in the front and none in the rear. Please let us know if you get it figured out. i will not be working on the front for some time. i currently have the rear out for rear control arm bushings, Eaton posi and 3:73 gear.

Thanks for replying, I'll let you all know how it goes come Wednesday.

[2500HD]

Any update MySons

[MySons68C20]

The new alignment didn't change anything.....it still won't return and the alignment shop tech said its in the box. I need to pull the pitman arm and see if there is a bind in the ball joints or?
Sorry for the late reply and Happy New Year!

[Rooster73]

If it were mine I would bust the outer tierod off the spindles and feel the ball joints for any stiffness or catches, kinda like checking u joints. Not saying anyone messed up but a ball joint can be ruined while pressing it in, especially the lower. Happy new year