Panhard bar question

[fourfive]

Would knowing the stock panhard length be helpful? I can go measure my spare for you.

Alternatively; if you know the delta between a level floor surface and each of the panhard bolts, Incould figure up the additional length needed over the stock bar length to position like a perfectly stock bar would..

Let me know, happy to work it up if that's helpful.

That would be cool if you have it handy. I remember reading on the spec sheet that came with my adjustable bar that a stock panhard is 37 1/8" measured from center bolt holes.

If you get around to it I'd definitely be interested in what measurements you come up with.

 

[JayRolla]

Are there measurements on the alignment sheet that confirm a centered rear axle?

Yes any good alignment shop will print a second sheet for rear adjustment. They will align the rear to track with the front end. Most places do not do this. My alignment shop does a lot of race cars for Pikes Peak hill climb. They do a lot of lifted rigs and highly suggested I go with an adjustable trac bar when I got aligned.

Once I aligned my rear end it drives perfect. I have had zero issues with rear end wag after aligning.

 

[jkeith.w]

Are there measurements on the alignment sheet that confirm a centered rear axle?

yeah, most modern alignment equipment will have an axle offset screen that will give wheelbase and offset dimensions when the sensor are mounted and compensated.

the stock bar is 940mm (at least mine is) center-to-center. I did the various lengths here for the various lifts.

hopefully with the bracket kit you are within 1/2 inch in height from one end of the bar to the other - in which case you'd be virtually stock length.

 

[jkeith.w]

I remember reading on the spec sheet that came with my adjustable bar that a stock panhard is 37 1/8" measured from center bolt holes.

37 1/8 inches is 942.98 mm; which would be the length one would want for a 74.85 mm delta between the ends of the panhard bar (2.946 inches.)

That being said, it should only recenter the axle 3mm... (if my maths are right)

 

[fourfive]

Once I aligned my rear end it drives perfect. I have had zero issues with rear end wag after aligning.

Do you happen to know what length they adjusted your bar to?

 

[fourfive]

37 1/8 inches is 942.98 mm; which would be the length one would want for a 74.85 mm delta between the ends of the panhard bar (2.946 inches.)

That being said, it should only recenter the axle 3mm... (if my maths are right)

Wow thanks. Im gonna have to review some of those math terms because I haven't taken a math class since 2005.

Ive seen the rear numbers on my alignment printouts that listed camber, toe, & thrust angle but I'm assuming the numbers for a centered rear axle is something else?

 

[JayRolla]

Do you happen to know what length they adjusted your bar to?

I would have to measure but us having different sized lifts I dont think it would madder.

 

[JayRolla]

Wow thanks. Im gonna have to review some of those math terms because I haven't taken a math class since 2005.

Ive seen the rear numbers on my alignment printouts that listed camber, toe, & thrust angle but I'm assuming the numbers for a centered rear axle is something else?

Most shops wont give you the rear adjustment since our rears are static and have not way to adjust. You would have to ask them to print this out and make the adjustment. My offroad/race alignment shop does this printout on all rigs just to show you if you need an adjustable trac bar.

 

[Tyler James Inc]

Yes any good alignment shop will print a second sheet for rear adjustment. They will align the rear to track with the front end. Most places do not do this.

Any good one, but most don't- meaning most alignment shops are not good?
I actually know exactly what you mean. I took my 4R to LesSchwabb after my LCA bushings replacement, and it wanders WAY worse than before they even adjusted it. I also told them to keep max caster priority, and they went backwards on one side. They even left one side in the red in two specs *

Once I aligned my rear end it drives perfect. I have had zero issues with rear end wag after aligning.

You had rear end "wag" even with the track bar? Seems weird for the axle being off-center to cause that. Mine only did that with the bar off.

 

[JayRolla]

Any good one, but most don't- meaning most alignment shops are not good?
I actually know exactly what you mean. I took my 4R to LesSchwabb after my LCA bushings replacement, and it wanders WAY worse than before they even adjusted it. I also told them to keep max caster priority, and they went backwards on one side. They even left one side in the red in two specs *


You had rear end "wag" even with the track bar? Seems weird for the axle being off-center to cause that. Mine only did that with the bar off.

Rear end wag seems to be a major issue when people lift. Most will say you need a panhard bar drop to get this fixed. My wag was mainly due to missing my rear sway bar. Installed and it pretty much tracked straight but would get a little wag here and there. Alignment shop told me this was due to the rear end needing adjusted and showed me how my rear end of was .75". Now with the adjustable panhard bar my rig rides perfectly fine with no panhard bar location mods.

 

[Tyler James Inc]

[MENTION=50342]JayRolla[/MENTION] you're lifted 3"+ in the rear with the bar in the stock location on both ends? I'd be curious to know how far off-center your axle is with some weight in the back. Maybe [MENTION=28464]eimkeith[/MENTION] and his math skills would answer that question. It, obviously, moves more drastically the more angle is on it, but I'd like to know how much. It's relatively long(the PH), so I would guess maybe .25" side-shift for 2" of sag. Pretty minimal, really.

 

[poopypants]

I had an extended pan hard on mine prior to doing the pan hard correction... Was just a pan hard my buddy cut in half, sleeved, then stuck on his truck and tack welded the sleeve to the ends at where it sat, pulled it and ran full welded around the ends... Was set for approx 5" of rear lift and with a bar that long and a lift that high, you got a massive angle on the bar. (Can measure the bar when I'm home)

Every little dip in the road, speed bump or drainage gutter I drove through that cycled my pan hard would send my axle waaaay drivers side and would oscillate me back and forth with all other control arms/sway/etc fighting to recenter it... Besides the bouncing up and down of the coils pulling the panhard up/down/left/right.... This was extremely accentuated when driving off road over actual sizable dips and obstacles.

I have to think it's even worse than having no pan hard on at all, because this is something physically pushing side to side even if otherwise going straight, not just body sway/inertia from side forces or cornering...

Even though I'm still about half an inch shy of being completely level, the difference is night and day. I could care less if I'm within factions of an inch of being centered side to side, what matters is I'm running a shorter stock pan hard that's almost level and imparts minimal horizontal travel to the axle as the suspension cycles.

 

[jkeith.w]

^ 3.25mm off-center if it's a stock bar on a 3inch lift, I believe.


Sent from my iPhone using Tapatalk

 

[fourfive]

I would have to measure but us having different sized lifts I dont think it would madder.

Agree but was just curious if the new adjusted length of your panhard for your 3.5" lift is within what SS recommended or if it had to be shortened a bit like mine.

 

[Tyler James Inc]

[MENTION=136095]poopypants[/MENTION] Although I hate quoting long posts, I agree with you 100%. And that's exactly what I was talking about when I asked about load vs axle side-movement. My rig handled bumps/dips just fine with no panhard, but corners had a weird "after-wag". That's actually why I left it off; I felt like the tension it would put on the suspension would have been worse than not having it on at all(temporarily).

 

[MountainBiker]

I forgot to measure if the axle was centered before pulling out of the shop last night but I did sight down both sides and it looked very close . Before it was obviously off center . My panhard bar is 1/4" off from being level . Unfortunately the drive shaft can still hit the gas tank skid but it hits farther back now . Part of this is probably because I haven't lowered the bump stops yet and I'm running Tundra 5100 shocks , they are a lot shorter then LC shocks and allow a lot of up travel . View attachment 233767

View attachment 233768

One way to get less driveshaft to gas tank skidplate impact is to us just a panhard bar drop bracket and no panhard lift bracket. The panhard bar lift bracket can cause more interference when the left rear tire is stuffed. If you draw it out you'll see what I mean. Someone on this forum made a few diagrams of this phenomenon, but I can't find it now.

Don't get me wrong, I bought the set of these awesome drop and lift brackets (and hope to get them welded on this month), but you just have to be aware of the geometry affects. Combined with my adjustable panhard bar (and lil skips gastank skid), I'll be able to find a compromise that keeps the axle as centered as possible, while not crashing the driveshaft into the gastank skid.

 

[JayRolla]

[MENTION=50342]JayRolla[/MENTION] you're lifted 3"+ in the rear with the bar in the stock location on both ends? I'd be curious to know how far off-center your axle is with some weight in the back. Maybe [MENTION=28464]eimkeith[/MENTION] and his math skills would answer that question. It, obviously, moves more drastically the more angle is on it, but I'd like to know how much. It's relatively long(the PH), so I would guess maybe .25" side-shift for 2" of sag. Pretty minimal, really.

I have 3.5" rear lift. Panhard bar mounts are stock. With my rear adjustable panhard bar Im dead center. Before alignment I was .75" off center.

 

[hounddogman]

One way to get less driveshaft to gas tank skidplate impact is to us just a panhard bar drop bracket and no panhard lift bracket. The panhard bar lift bracket can cause more interference when the left rear tire is stuffed. If you draw it out you'll see what I mean. Someone on this forum made a few diagrams of this phenomenon, but I can't find it now. .

I was aware of this and it's pretty much the only reason I did a drop as well as the lift bracket .

 

[poopypants]

Got out just at the end of the day yesterday to test the merit of my work with the panhard correction brackets.... Does the driveshaft clear the gas tank skid?

Answer is.........







just barely!

(Only mark is from my diff armor under the skid)

Looking now at my clearance, I could have probably gone higher on my axle side lift bracket, but better safe than sorry if I ever change up my suspension components... Probably bottoming out the shocks though...

This exact set of obstacles in my "backyard" would thrash my had tank skid on my rolled runner and the extended pan hard... So, nice to see I have chance on all these now!

 

[Tyler James Inc]

[MENTION=136095]poopypants[/MENTION] you running LC coils and Tokico/OEM shocks?