27" wheel well fender to ground on rear bags. What length panard bar?

[Low & Slow]

Looking to put in a longer bar for my rear bag drop but cannot tell any ride difference between pre and post bag setup. Still plenty of wheel to fender room and axle looks centered to me.

I was told that I would need on average a 1.5" longer panard bar. How long is the factory bar? Should I just add 1.5" and Call it a day?

At a ride height of 27" from ground to fender how long should it be? Do I even need a new panard if all appears kosher?
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[WORP67]

If you dont have a triangulated 4 link you will need a panard bar. If not your axle will move side to side. Your best bet is to sit it at the height you want to ride at and measure the distance between mounting points.

Tire and wheel size will effect where your axle sits at 27" ride height. A truck on 17" with a 2" side wall on the tires center of axle will be ~9.5" and on a 20" with a 2" side wall your lookin at ~11" to center of axle. So you really cant just say 27" wire height to fender cause of the differences in wheel and tire combos change stuff.

Best bet is to sit it at the ride height you want and measure.

[SCOTI]

Originally Posted by WORP67

Your best bet is to sit it at the height you want to ride at and measure the distance between mounting points.

Exactly. If you're adapting your original Panhard bar, this is how it would need to be done.

[WORP67]

You could set up a watts link. It would keep it centered with ride height. Bad thing about a panard bar is that its only centered at one height. With something like a watts link it can keep it centered at all times.

[texastrendz]

Originally Posted by WORP67

You could set up a watts link. It would keep it centered with ride height. Bad thing about a panard bar is that its only centered at one height. With something like a watts link it can keep it centered at all times.

Some drawbacks to a Watts system also.

[SCOTI]

The simple nature of the Panhard bars function & ease of installation makes it a far better choice for the novice and/or mild builder. To install a watts link correctly takes some knowledge (correctly= installed correct & functions correct).

[Low & Slow]

I'm a little confused. If I set the panard length aired down but then need to air up for a haul of fire wood do I need to again adjust the bar?

I was going to have a buddy lengthen mine for the lower stance but the question of airing up bothers me.

Also, if at ride hit I'm having zero rubbing of the tires in the well is there an immediate need for a panard bar adjustment?
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[WORP67]

Originally Posted by texastrendz

Some drawbacks to a Watts system also.

This is true but at the same time there is always some sort of drawback.

The thing with a panard bar is the its one length. If you have it at a certain length at a certain ride height then if you go lower than hat the axle will move over one way. If you go higher than that the axle will mover over the other way.

If you have enough movement you can be into one bed side when aired down and at full lift be stickin out the other side.

If your rear end is centered at ride height then you should be ok to drive. If its not centered at ride height then its can put extra wear on tires, bushings, bolts, and anything else in your rear suspension(can even wear out the carrier bearing if you still have a 2 piece drive shaft) . As well as make the truck crab goin down the road.

[SCOTI]

Originally Posted by Low & Slow

I'm a little confused. If I set the panard length aired down but then need to air up for a haul of fire wood do I need to again adjust the bar?

I was going to have a buddy lengthen mine for the lower stance but the question of airing up bothers me.

Also, if at ride hit I'm having zero rubbing of the tires in the well is there an immediate need for a panard bar adjustment?

That's the drawback of the Panhard bar w/an adjustable suspension.

To minimize the problem, you want the bar as long as possible. It needs to run from the frame rail on one side to the truck arm on the opposite side. Just correcting the length for your new ride height w/the bar attached to the center of the rearend housing will still leave you w/a short-ish bar that will allow more side to side shift as the suspension travels (vs. a long bar).

You will likely have .500" side to side shift w/the 'long' bar I mentioned above which is usually 'do-able' for most applications. Regardless if it's a long or short bar, it's only going to be centered @ whatever height you build it for. Higher or lower than that will allow the side shift. You don't have to re-adjust it when you change the suspension height; it just won't be centered (or optimum) @ the different height.

The shorter the bar is, the worse the side shift is....

[Low & Slow]

Excellent info! Thank you again!

Tomorrow I'm moving into a place with a two car garage complete with pit I absolutely cannot wait to tear into the truck underneath.

What adverse effects of the short panard bar should I look for? The rear feels tight over bumps now but there is zero rubbing. Would this be caused by a panard being too hard? I'll be looking at possible mounting locations for a long bar tomorrow as well.
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[SCOTI]

Originally Posted by Low & Slow

Excellent info! Thank you again!

Tomorrow I'm moving into a place with a two car garage complete with pit I absolutely cannot wait to tear into the truck underneath.

What adverse effects of the short panard bar should I look for? The rear feels tight over bumps now but there is zero rubbing. Would this be caused by a panard being too hard? I'll be looking at possible mounting locations for a long bar tomorrow as well.

The previously mentioned extra side shift because of the bar length & poor geometry using the factory mounting locations once the ride height is dropped lower than stock.

The bar should be set as close to level as possible @ ride height. The factory mounts are not condusive toward this goal. The drivers/frame mount is typically useable if the pass/rear-end mount can be set-up to achieve level mounting @ ride height.

The short bar in the factory locations can/will still get the job done.... it just won't be optimum.

[Low & Slow]

So I have been busy trying to track down the source of a vibration in the chassis and haven't had a chance to set my bar length. Would a shaking around 50mph be a symptom of the rear dog legging?

I don't have any tire rub out back, just this damn vibration I'm tring to mend before moving forward. The vibration stops when the wheel is turned even slightly.
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[SCOTI]

Originally Posted by Low & Slow

So I have been busy trying to track down the source of a vibration in the chassis and haven't had a chance to set my bar length. Would a shaking around 50mph be a symptom of the rear dog legging?

I don't have any tire rub out back, just this damn vibration I'm tring to mend before moving forward. The vibration stops when the wheel is turned even slightly.

Yes. The rear joint needs to be in phase w/the front joint.

Just like the pinion vs trans output angle (up/down comparison), you don't want excessive angle side to side. The rear housing kicked over more than optimum can cause binding @ the u-joints that is more pronounced @ certain speeds.

[Low & Slow]

How about this question, I read on here that the factory panhard bar was 27" eye to eye. I measured mine lastnight and it was 24" and painted red. Also, I only have about 1/2" between my diff cover and the factory bar. That doesn't seem right at all.

Thoughts?

[WORP67]

It may not be a factory be or might be modified. Are there any welded that dont look factory?

[Low & Slow]

No sir, no welds on it. Its just red in color and rest of my suspension is yellow.

[VA72C10]

Great info here!!!

[WORP67]

I dont know factory lengths and if any have diff heights but, it does sound as it has been replace at one time or another if it does seem to match any of the other suspension. Does it appear to be old or does it look like it had been recently replaced before you purchased the vehicle. Some one may have bent or messed up the factory one and just found one that was close in a salvage yard and swapped it out or ordered a aftermarket one it is was just a bit different. Does it look like the axle is sitting offset or either one of the mounts have been relocated to work with the shorter bar?

[Low & Slow]

I just so happen to have a pic from before I put in airbags in. There really is no way to tell if its offset now with the new stance as it definitely is pulling to the drivers side.



*Notice how little clearance there was between the pumpkin cover and the bar at stock height.

The mounts on both the axle and the frame rail look factory to me. In fact, so far the frame mounted bar bolt is the only one on the truck which my impact gun has been unable to break free.

I did pickup an adjustable bar and have it sitting in the garage waiting to go on.

EDIT: Damn my rear coils were shot!

[SCOTI]

There isn't much room from the factory between the cover & the Panhard bar.
The locations where the bar is mounted in that pic are the factory mounting points for a 67-72. The bar in the pic 'looks' like it's the correct (factory) length.

[Low & Slow]

Measured the distance eye to eye again last night and its 24". I read on here that factory LWB 1/2 ton length was 27". Thats what really caused me concern.

[SCOTI]

Originally Posted by Low & Slow

Measured the distance eye to eye again last night and its 24". I read on here that factory LWB 1/2 ton length was 27". Thats what really caused me concern.

You measured eye to eye. Was that from the centerline of eye to eye? Was the measurement you noted previously (the 27" number) done the exact same way?

There were longer bars from the factory. They were used on the 64-66 models (not all). Instead of mounting @ the top of the right hand corner of the differential, the mount was on the axle tube about 1/2 way between the differential & the end of the housing.