stock panhard rod angles/installing adj panhards (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Jan 18, 2023
Threads
7
Messages
122
Location
GA
I've been thinking about how to set the adjustable front and rear panhards, but didn't figure it out until after I put the lift on. I was hoping someone might could measure the stock panhard rod angles at stock ride height to help confirm. If the baseline angle and rod lengths are known, I think the correct new length can be calculated precisely as follows:

stock rear panhard length: 31.75" (ctr to ctr of bolt holes taken from search)
stock panhard angle: 10 deg (guessing for now)
rear lift height: measured on truck at 2.75" over stock

new panhard rod length calculation using right triangle maths:

31.75" * sin(10deg) = 5.513" (height between stock mounting bolts)

(31.75^2 - 5.513^2)^0.5 = 31.268" (horizontal distance between stock mounting bolts)

5.427" + 2.75" lift = 8.177" (lifted height between stock mounting bolts)

new panhard length required = (8.177^2 + 31.268^2)^0.5 = 31.268" or 0.482" longer than stock


I only adjusted mine to be about 1/8" longer, and the axle was pretty well centered, so I'm guessing the stock rod angle is smaller than 10deg.
 
For the rear, something like the Delta panhard relocation bracket and using the stock panhard will be a better choice. Gets rid of the 'tail wagging' effect as the rear cycles over undulations. It is a very noticeable improvement in handling.

Search, lots written about it already.

cheers,
george.
 
For the rear, something like the Delta panhard relocation bracket and using the stock panhard will be a better choice. Gets rid of the 'tail wagging' effect as the rear cycles over undulations. It is a very noticeable improvement in handling.

Search, lots written about it already.

cheers,
george.
I understand that and have already ordered the Delta bracket. Still need to set my front panhard though. Could not find the angles when I searched, and did not see where anyone had tried this way for setting the length.
 
As noted the Delta brackets are on order. I agree that moving the mounts closer together vertically is the only way to correct an increase in the panhard angle so that you get the correct travel arc. I'm not debating that. However, I still am going to adjust the front, and I believe this is the correct way to set that length, I just need the stock panhard angle. I also figured this might be useful for someone in the future who for whatever reason might have adj rods they got for cheap, etc.
 
As noted the Delta brackets are on order. I agree that moving the mounts closer together vertically is the only way to correct an increase in the panhard angle so that you get the correct travel arc. I'm not debating that. However, I still am going to adjust the front, and I believe this is the correct way to set that length, I just need the stock panhard angle. I also figured this might be useful for someone in the future who for whatever reason might have adj rods they got for cheap, etc.
I think you’re over thinking it. Just use it to center the axle at ride height. The angle is kind of a moot point.
 
I'm overthinking it so others won't have to. There's no need to do the extra work of loosening the bar a few times and measuring axle centering with eyeballs and garage tools when you could check this thread (once it's solved) and set it to the factory location on the first go.
 
I'm overthinking it so others won't have to. There's no need to do the extra work of loosening the bar a few times and measuring axle centering with eyeballs and garage tools when you could check this thread (once it's solved) and set it to the factory location on the first go.
But… it doesn’t really matter in the first place
 
I'm overthinking it so others won't have to. There's no need to do the extra work of loosening the bar a few times and measuring axle centering with eyeballs and garage tools when you could check this thread (once it's solved) and set it to the factory location on the first go.
You're overthinking it because every build is different. My axles are offset from center, but the tires rub equally on both sides. There is no simple math equation. In fact in most situations the stock length is essentially correct- as you yourself have verified. In most cases the adjustability of the panhard only helps with alignment of the bushings, rather than relocating the axle.

Also, good luck finding the stock angle. Adding any weight, such as a passenger, will change the angles. Also, the change in length is exponentially related to the change in height, not linear. Hell, 'exponential' may not be the right term, as what you're dealing with is degrees of a circle rather than slope. You need to use circle math, not triangle math. In any case, panhard adjustment is a trial and error procedure, dependant on many variables such as spring rate, tire size, wheel offset, axle travel, weight carried, center of gravity, etc.
 
Also, good luck finding the stock angle. Adding any weight, such as a passenger, will change the angles. Also, the change in length is exponentially related to the change in height, not linear. Hell, 'exponential' may not be the right term, as what you're dealing with is degrees of a circle rather than slope. You need to use circle math, not triangle math. In any case, panhard adjustment is a trial and error procedure, dependant on many variables such as spring rate, tire size, wheel offset, axle travel, weight carried, center of gravity, etc.
The travel is an arc. A static height change where the bar length is being adjusted to maintain the stock horizontal distance between the mount locations is a right triangle. I'm not trying to correct the dynamics side, just want to minimize my limited time to work on it, and have a good reference point for understanding where I started at when I'm fine tuning later.
 
Only way to make it the same angle as stock is to move the mounting point if you do that you will have to alter the steering drag link to the same angle if not it will increase bump steering. An adjustable front pan hard bar is to center the axle back to stock location because the lift kit raised the chassis up witch pulls the axle over. As stated above just center the axle back under the truck unless you want to redo suspension and steering.
 
Only way to make it the same angle as stock is to move the mounting point if you do that you will have to alter the steering drag link to the same angle if not it will increase bump steering. An adjustable front pan hard bar is to center the axle back to stock location because the lift kit raised the chassis up witch pulls the axle over. As stated above just center the axle back under the truck unless you want to redo suspension and steering.
Right. Not looking to change the rod angle on the front. Is matching the stock horizontal distance between the axle mount and chassis mount not the best way to center the axle?
 
You need to measure from the frame to the inside of the wheel or tire on each side. There is no magic number to go by that works for every lift.
 
You need to measure from the frame to the inside of the wheel or tire on each side. There is no magic number to go by that works for every lift.
Agree there's no magic number. The measured lift height is a variable that's accounted for. Are the front and rear axles not centered from the factory such that the track widths are centered relative to one another? I still don't understand why the factory horizontal distance between the mounts isn't a good reference starting point if I don't need to tweak the axle location for tire clearance, etc. It's also difficult to accurately measure axle centeredness in a home garage, especially when the adjustment I'm looking to make is very small on the order of 1/8".
 
Agree there's no magic number. The measured lift height is a variable that's accounted for. Are the front and rear axles not centered from the factory such that the track widths are centered relative to one another? I still don't understand why the factory horizontal distance between the mounts isn't a good reference starting point if I don't need to tweak the axle location for tire clearance, etc. It's also difficult to accurately measure axle centeredness in a home garage, especially when the adjustment I'm looking to make is very small on the order of 1/8".
I think maybe you should do some research on this subject so you better understand the topic.
 
I'm not trying to be negative or anything. I'm just saying altering some suspension is ok but there is more to it. I would say research trailing arm suspension with a pan hard bar just for the knowledge of it. As far as installation of adjustable pan hard bar it easy put it on measure each side to center the suspension under the truck and be done with it. Easy peasy
Tommy
 
Another way in your garage is stick a tape measurer in the wheel well till you touch the top of the coil bucket and then the outside of the tire, looking at lugs (some stick out more than others) Now do the same on the other side. It will tell you if you are centered or not.

Is it Tuesday?
 

Users who are viewing this thread

Back
Top Bottom