Hi all.
I have a problem with my frond end.I did my SAS on my Sidekick more than a year ago.It was(and still is) 3 link front with panhard and wishbone rear.
A bit of History
My first panhard was a Z shape bar.Upper mount behind stock pitman arm,lower mount -same height next to the lower drag link mount on the steering arm.Everything was ok.
Recently I decided to replace the Z panhard with a straight one .Lower mount almost same as previous(a bit higher),upper 2 inches lower than the height where stock pitman arm is.The result was bump steer and body roll, not too much but it was annoying.
So I decided to get a drop pitman arm in order to lower the drag link too.I ,saw that with the drop pitman,the upper drag link mount would be a bit lower than the last panhard upper mount.So I ordered the drop pitman arm that Calmini makes for Sammies that use Sidekick's steering box.
From this point everything got worse.Truck stands still,I turn the steering wheel and I had body roll.In addition,when turning on the street the axle was "walking" when on turn.The steering had become too sensitive.I searched more in here,learned more about panhard,and I made a new one.Note that I use rod ends on both ends of the panhard.
Here is the current set up


lower mount


upper mount (you can also see the Calm drop pitman arm)




What wrong do you see in these photos
I m asking this cause I still have a little bumpsteer,not a problem but its annoying.When going straight and passengers side wheel hits a bump ,the steering wheel turn (right if I remember right) for 2" and comes back to its straight position.It also gives me the impression that its the start of a death wobble which is not going to happen of course (panhard mounts-rod ends ,every thing else checked).
I cant find why this is happening and I need a little help.
Have in mind the following :
- Caster checked,toe in-out checked,differential position(i.e centered) checked,panhard mounts,ends -drag link's ball joints checked.
- I tried to make the panhard and drag link mounts at the same height.(I relocated the lower panhard mount-lower /I still have a slight body roll when truck stands still but its almost as if its not there,I ll raise a bit the lower panhard mount to get it at excactly the same height as the lower drag link mount is/that is where the bolt goes through the steering arm)
- Panhard and drag link are parallel to each other and
- they have almost the same length.I didnt have space to make the panhard same length as the drag link but I dont think thats its very significant cause the difference is that the panhard is aprox. 1,6 inches shorter.
I ve noticed that the lower panhard mount is less than half inch lower than the lower drag link mount.This makes them almost parallel but not completely parallel.Could this be the origin of the problem?
Another thought is that something is wrong with the drop pitman arm.I m not sure but it makes the steering very sensitive and immediate.A slight turn and the truck turns a bit violently.Is there a case that its not the right pitman for me ? I thought that pitman arms were just for lowering the upper drag link mount.I know that they can be just a bit longer than the steering arms,but not too long.If you check the photos,I think you ll see that its just a bit longer.
Is there a case that it drops too much the upper drag link mount?
Any tech theory about drop pitman arm besides the fact that it stresses the steering box ?
Cant think of anything else,so I thought that its better to ask for your help.I m ready to cut everything ,replace the pit man arm with the stock one and relocate the upper panhard mount.The only problem with this ,is that when suspension flexes ,the drag link gets too stressed.
Thanks

I would move the streering box to the out side of the frame (toyota ifs box or fj 80) so that your drag link and your panhard bar are the same length, if you jump up and down on your front bumper and your streering wheel moves you have a problem, every thing else looks good so far, make sure your panhard bar and mounts are super beefy it takes alot of abuse.

I would move the streering box to the out side of the frame (toyota ifs box or fj 80) so that your drag link and your panhard bar are the same length, if you jump up and down on your front bumper and your streering wheel moves you have a problem, every thing else looks good so far, make sure your panhard bar and mounts are super beefy it takes alot of abuse.

I ll check how this can be done,never thought about moving the box.I think its a lot of work though.Cause I m planning to upgrade in stronger axles soon (max in 2 months) ,so I dont want to do something that would cost time and money for this set up.I thought about remounting the zuki steering box 1' forward (there is some space there) so that the upper panhard end comes forward too.Now it cant pass between pitman and coil.Thats why I did it inwards.
I think that the drop pitman revealed or intensified a problem.A fact is that with this set up,where the panhard is 2,5" shorter ,


I didnt have any problems at all.Of course now the trucks sits +1" higher.I dont know...
Thank you very much mrfuelish.
P.S :If there are somewhere any photos (or links) available showing outside of kick frame,installed Toy IFS st.box,please post them here or send p.m.

Is there a particular reason why you mounted the wheel end of the draglink below the steering arm at the passenger wheel instead of above it?

I was of the impression that bumpsteer is caused by suspension modifications that changes the "stock" (or optimum?) vertical distance between the pittman arm end and the steering arm end on the draglink. 

If you moved the draglink connection to the top of the arm, you would reduce this angle making it closer to horizontal when the suspension is at it's neutral load position - like when you are driving it down the street.   

To better explain this,  unlock the steering column and jack up your truck on the frame on the passenger side front.  Watch the pittman arm and steering wheel for motion as you raise the frame and change the angle of the draglink.  I bet the steering wheel with start to turn clockwise - just as it would when you hit a bump.

Also, (this is just guessing...) wouldn't the problems that you would be having with the panjard bar be reduced if the panhard bar was connected to the passenger side on the frame and the driver's side on the axle so that it would work in the opposite direction of the steering gear? 

This pure speculation on the part of a guy who did really good on the "if you folded up pictured cardboard as marked what kind of box shape would you end up with" section on the College SAT test a gazillion years ago...   

Is there a particular reason why you mounted the wheel end of the draglink below the steering arm at the passenger wheel instead of above it?

I was of the impression that bumpsteer is caused by suspension modifications that changes the "stock" (or optimum?) vertical distance between the pittman arm end and the steering arm end on the draglink. 

If you moved the draglink connection to the top of the arm, you would reduce this angle making it closer to horizontal when the suspension is at it's neutral load position - like when you are driving it down the street.   

To better explain this,  unlock the steering column and jack up your truck on the frame on the passenger side front.  Watch the pittman arm and steering wheel for motion as you raise the frame and change the angle of the draglink.  I bet the steering wheel with start to turn clockwise - just as it would when you hit a bump.

Also, (this is just guessing...) wouldn't the problems that you would be having with the panjard bar be reduced if the panhard bar was connected to the passenger side on the frame and the driver's side on the axle so that it would work in the opposite direction of the steering gear? 

This pure speculation on the part of a guy who did really good on the "if you folded up pictured cardboard as marked what kind of box shape would you end up with" section on the College SAT test a gazillion years ago...   

Hi and thanks for your comnents.You made me feeling a bit confused though...
As far as I know ,steering arms have conical mounts,so I dont think its possible to mount the lower drag link end  upside down.
Till now I never saw an upper panhard mount to a diffarent frame rail than where the srteering box is.I dont think it will work since they will create opposite forces.

At least thats what I know so far....

I ll check again the steering parts.The steering day by day becomes loose ,at least that's what I feel.The last two days I could feel the bumpsteeer but I was also feeling a slight tendency for death wobble. As a proof for this,today when I hit on purpose a small bump as I was driving on the street, I had death wobble.....and I was obliged to use the brakes in order to stop it before getting worse......  unbelievable.
I didnt expect death wobble,cause the last time I had DW ,it was because I used soft bushings for the panhard ends.When I replaced them with rod ends,DW dissapeared.
Now here it is again....

now first off, i'm a dummy so what i say might not mean shit. from my little knowlege the panhard should be level with the axle, not at an angle as shown. thelength does not matter as much as it being level. the flatter(more level with the axle)the less bumpsteer you will experience. as MR FUELISH pointed out the mounting points MUST be rigid and strong if they flex at all you will get a nasty bumpsteer(and a death wobble under the right circumstances). have a friend steer it while you check it out . i'm guessing you have a mount that is flexing.
panhards are a real bitch because they have an incredible unimmaginable ammount of force on them, especally when wheeling. where you wont notice it on the trail , the minuit you take it back on the street it will become apparent
good luck i'll take a pic of mine and post it in a few
jason

On your Death wobble I would check your steering dampener first,king pins second,and then on to your tires, most large tires cannot be balanced on the rim, if you balance the rim and the rubber on the tread is what is out it will wobble on the rim even though it looks good on the spin balancer, if you use a weight patch it will wear a patch of the tread out if you drive it on the highway,dynabeads are prob. good but at 65.00 for four wheels I would go with lead shot, bb's, golf balls ect. and try that out, also if you get a little mud on the rims it will still balance out.

now first off, i'm a dummy so what i say might not mean shit. from my little knowlege the panhard should be level with the axle, not at an angle as shown. thelength does not matter as much as it being level. the flatter(more level with the axle)the less bumpsteer you will experience. as MR FUELISH pointed out the mounting points MUST be rigid and strong if they flex at all you will get a nasty bumpsteer(and a death wobble under the right circumstances). have a friend steer it while you check it out . i'm guessing you have a mount that is flexing.
jason

From what I know,the ideal is to have both drag link and panhard parallel to the axle.But if this is not possible due to suspension lift,no hi steer,no drop pitman arm,then we preffer the drag link and panhard to be at a slope to the axle but parallel to each other and to have the same length or aprox the same length.If the panhard is at a steep slope to the axle and its not parallel to the drag link ,then apart from bump steer,we will also have wheel steer as suspension moves.
I thought to make the panhard parallel to the axle but I believe that this will cause incerdible bump steer since the drag link cannot be parallel to the axle.
Another thing about the panhard is that we should try to make the mounts at excaclty the same height as the drag link mounts are.If we dont do this ,we will have body rolll when we turn the steering wheel even if the truck stands still.
This is what I know about the panhard.If something is wrong I ll be glad if someone could tell me so ,cause then I ll have to do something different to my current set up.
One thing I m not sure is if a small difference in length is a problem.

One thing I noticed though,is that I made the panhard from a seamless tube ,but lighter than the Z shape one I had in the past.I used a lighter one cause I thought that since its a straight line now and not Z ,it will be strong  enough.I think I ll reinforce the panhard tube.
The panhard mounts are ok,king pin bearings and wheel bearings are new.wheels are ok.

Can I see a side shot of your lower links?

GRVIT,

From what I can see I would check the following:

I noticed you fabricated up a new upper panhard mount - it looks too open and could flex under extreme pressure. You may want to fully box it in.

Your panhard rod looks pretty small - these things take a LOT of pressure - perhaps a heavier wall, larger diameter one would be better.

I noticed your drag link is bent in the first pic's - if it is the same link then check to make sure it has not been compromised after straightening.

Panhard rod - drag link. Must be parallel to each other in the horizontal AND vertical plane for best results. They also need to swing in the same arc - lengths can be different to achieve this result ( you may want to draw this out on paper to understand it fully, but it does work ).

You mention that when your vehicle is sitting static and you turn the wheel that the corner lifts - this is most likely caused by your castor setting -  5-6 degrees is stock.

You mention that you are running a three link with panhard rod. Are your links set up correctly? Sometimes if you mount your lower links below the axle centre line too far you can experience "axle tramp / twist" because the upper link cannot resist the axles twisting effect - leverage is the culprit 

Well that should get you started. Good luck with your project.

BTW: In case you were wondering. I built a Vitara with a beam front end on coils - four link with panhard rod. Running 37's and it drives very well.

Not sure if I am on the right track - pretty hard this internet diagnostic stuff 

ZeusZuki 

thanks ZeusZuki.You are very observative.
So the photos are a bit old,for example at the rear end the shocks are now to the inside of the rear axle.anyway,you will see the mounts.
So   rear end


Front end -mounts




The upper axle mount is at such height in order to elliminate the forces from the lower(s).At least I think it is.

Have a look at them and tell me what you think.
The panhard is lighter ,yes.I ll make a new heavier one and I will raise its lower mount 1/2" to have the same height with the lower drag link mount.
The drag link is the same,it was bent a bit ,I think its ok but I might sleeve it.
About what you mention that Drag link  and panhard have to swing in the same arc.If they are parallel,they will swing in the same arc ,wont they? I have some doubts about the length issue.Some say they must have the same length or to be as close as possible.I tried to do the same.
I said that when the truck was standing still and I turned the steering wheel I had body roll.Yes ,as far as I know this is happening when panhard mounts and drag links mounts are not in the same horizontal height.That difference creates body roll.At least this happened and when I mounted them in the same height (uppers-lowers) the body roll dissapeared.
As for the caster ,after making the first straight panhard and making the necessary adjustments,I forgot to check the caster.I did it recently due to problem and it was almost 0.I adjusted it to 8 degrees just in case the steering becomes a bit heavier.Despite the 8 deg adjustment,the steering was heavy at first then after one day wheeling,its feeling loose again.I ll reduce it to 6.
Now I m going to buy some DOM tube ...
By the way the steering dampener is ok,its very stiff,hard to open even with both hands.
Well,thanks for the comments , I ll keep on checking things for the moment.

and in case it helps more this is when wheels are straight


this when wheels are to the left


this when wheels to the right


Also , I noticed that when I use the brakes a bit hard ,the front end tends to go left (driver side).

ZeusZuki ,do you have a pic where the panhard and draglink  are mounted in such a way that they ll swing at the same arc ? Or you can use MS paint and draw some lines on one of my photos.
What is the excact effect of panhard length.What happens if its short or long or the same with Draglink? There must be a difference...

good luck i'll take a pic of mine and post it in a few
jason

thanks,a pic will be helpful.

Quote from: locjaw on December 23, 2006, 01:31:13 PM

good luck i'll take a pic of mine and post it in a few
jason

thanks,a pic will be helpful.

i cant get my pic downloaded. my comp crashed a while back and i lost all the programs, i'll try to find one though
jason