Loose Steering

[77cruiser]

My steering on my 62 is really loose, causing the truck to wander pretty good. Its got 4" lift springs on it with 3/4 over stock shackles. TRE's look to be in good shape and it has a brand new OME ss on it too. I read one post where someone tightened some springs in thier tre's but I just want to get it tighter so its not wandering so bad. Suggestions? will shimming front end help?

 

[Trapper50cal]

Although

Although I can't remember the name specifically, there is a "backlash" or play adjustment on the top of the steering box, which should take the play outta the steering if all else is well.

with that much lift, there should be at least 4-6 degrees of shim, but thats for turning/steering axis correction

 

[IndianDoc]

My steering on my 62 is really loose, causing the truck to wander pretty good. Its got 4" lift springs on it with 3/4 over stock shackles. TRE's look to be in good shape and it has a brand new OME ss on it too. I read one post where someone tightened some springs in thier tre's but I just want to get it tighter so its not wandering so bad. Suggestions? will shimming front end help?

My guess is TRE are shot, may look ok but lots of play potential, also bushings in the system may be allowing too much play. But from your description I would suspect that whover did the lift did not get the toe in right and you have little or no toe in. That helps the wander better than anything. Also damper may be shot. Just grab a hold shake and see how much play you have in the componets and try the alignement measurements that are in several threads on mud. Still just guessing but that toe in sure may be the problem. If not start looking for worn parts. I agree with trapper too, but I sure would check alignement before jumping into other stuff. The set screw on top of the ps box is accessed from the engine compartment back off the set screw and you can then tighten up the screw, again read the threads on stearing and you can find how to adjust it correctly or FSM has good info. Good Luck

 

[Cruiserdrew]

With a 4 inch lift and extended shackles, don't "fix" anything until you get your caster measured at an alignment shop. If your caster is bad, which it almost certainly will be, fix that before fixing anything else.

The other likely cause of slop is adjustable drag link ends. They are almost always too loose or worn out. You can try adjusting the adjuster screws all the way in then out 1/4 turn.

It is unlikely the problem is the steering box backlash. That is easy to screw up so don't mess with it until you have checked the easy stuff.

My money is on the caster being off and the drag link ends being shot.

 

[Trapper50cal]

So

So Toe-in should be about but no more than .25" correct? and is it correct that the shims correct the horizontal nature of the steering axis thereby eliminating "bump steer"?

 

[Cruiserdrew]

So Toe-in should be about but no more than .25" correct? and is it correct that the shims correct the horizontal nature of the steering axis thereby eliminating "bump steer"?

Trapper -no offense but where are you getting this confusion in terms?

There is a toe-in spec and it's very easy to set with a tape measure. .25 would be a lot but not unreasonable, more like 1/8 inch is about right unless you have very large tires.

Bump steer occurs because of a change in the relative length of the drag link when 1 wheel hits a bump-that's why it's worse with a more steeply angled drag link and better if the drag link is nearly horizontal. It's all trigonometry. You can see why high steer is almost always preferable in a SOA-the drag link is close to level.

"Shims" go between the spring and the perch, and are used to correct the vertical aspect of the steering axis. That is the CASTER angle. It has little or nothing to do with bump steer. Usually when a truck is lifted, and especially if longer shackles are used, the caster goes toward 0 and can even become negative. This leads to very squirrely steering, especially under hard braking.

You can also set the correct caster by rotating the knuckle, ie a cut and turn, but that is a lot more work when a caster shim will likely do the trick.

For the original poster, post up some aligment numbers and look for slop in the drag link ends (they are the spring loaded ones) and report back.

 

[Trapper50cal]

Trapper -no offense but where are you getting this confusion in terms?

There is a toe-in spec and it's very easy to set with a tape measure. .25 would be a lot but not unreasonable, more like 1/8 inch is about right unless you have very large tires.

Bump steer occurs because of a change in the relative length of the drag link when 1 wheel hits a bump-that's why it's worse with a more steeply angled drag link and better if the drag link is nearly horizontal. It's all trigonometry. You can see why high steer is almost always preferable in a SOA-the drag link is close to level.

"Shims" go between the spring and the perch, and are used to correct the vertical aspect of the steering axis. That is the CASTER angle. It has little or nothing to do with bump steer. Usually when a truck is lifted, and especially if longer shackles are used, the caster goes toward 0 and can even become negative. This leads to very squirrely steering, especially under hard braking.

You can also set the correct caster by rotating the knuckle, ie a cut and turn, but that is a lot more work when a caster shim will likely do the trick.

For the original poster, post up some aligment numbers and look for slop in the drag link ends (they are the spring loaded ones) and report back.

Got yah, basically, its stupidity that and confusion. I can picture whats happening, I just don't have the right terms for the action. I always use bump steer incorrectly I guess. I should just not use it. The caster is what I'm thinking of , I think I just confuse it with camber. I just know that a front diff that is not level means the axis is high in the back and low in the front since its no longer level. I will just not post on this subject until I know it a little better.

I run 35's and am just below .25" on toe in

 

[Trapper50cal]

Is this correct?

By trapper50cal at 2008-06-30

 

[brian]

lifting a solid axle truck with springs does not normally get into caster angle correction. 1-2 degrees at most just to help center the larger tires.
it's when you start messing with longer shackles, on a NON shackle reversed truck that you get into caster angle shims.

with the motor off IE no power to the power steering, how much slop does the steering wheel have before the front wheels want to start rotating?

 

[lehiguy]

Get the easy stuff. If you used longer shackels you will likely need 2 or 2.5 degrees of caster shims between the spring and the axle; fat end forward if you haven't done a shackel reversal. Check the drag link ends, that's free. Also check for steering box play, also free. This should have a maximum out of pocket of about $20 for the shims if you need them. The garage alignment has been working for me for more than a decade. You should have this tight pretty quickly.

 

[77cruiser]

addtional details! Alignment has been done twice( i wasnt happy first time so i took it back and told em to redo it), steering dampener is brand new OME. I did replace on TRE but not all of them.
SOunds like i need to take it and get the castor measured.
I was going to try to do a good exam of the TREs this weekend to see what i got. When I have someone turn the steering wheel i should not see the linkage move much without the wheels moving at the same time right, if so they are needing to be replaced?

 

[lovetoski]

addtional details! Alignment has been done twice( i wasnt happy first time so i took it back and told em to redo it), steering dampener is brand new OME. I did replace on TRE but not all of them.
SOunds like i need to take it and get the castor measured.
I was going to try to do a good exam of the TREs this weekend to see what i got. When I have someone turn the steering wheel i should not see the linkage move much without the wheels moving at the same time right, if so they are needing to be replaced?

I think you are on the right track. Cruiserdrew's first post was right on the mark....
1. Get the caster right. Spring lifts vary, caster is measurable and makes a huge difference. Start here.
2. Once caster is right, then re-evaluate. If still too loose, tighten the TRE's. (as per CD's instructions above). They are a wear item, so no harm in just replacing.
3. Once caster and TRE's are in spec, you should be good to go. The only remaining points of slop are: steering shaft, steering box, and ...it's a truck...it'll always be kinda loose.

HTH!

 

[lehiguy]

addtional details! Alignment has been done twice( i wasnt happy first time so i took it back and told em to redo it), steering dampener is brand new OME. I did replace on TRE but not all of them.
SOunds like i need to take it and get the castor measured.
I was going to try to do a good exam of the TREs this weekend to see what i got. When I have someone turn the steering wheel i should not see the linkage move much without the wheels moving at the same time right, if so they are needing to be replaced?

Start with the FREE STUFF! The drag link ends are adjustable for a reason, so is the steering box. At least you will eliminate them as suspects if nothing more.