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View Full Version : Panhard bar on Truck Long arm suspension



Johnny Blaze
09-23-2011, 04:22 AM
I just installed a long adjustable panhard bar on my 69 c10 with the long arm suspension.

I noticed the bar does not run close to parallel to the rear axle, when viewed from behind or above.

I thought with my torque arm camaro anyway, that you want the panhard bar as close to parallel to the rear axle as possible.

Is this true with the long arm as well? Or does the long arm need it angled to keep it all striaght like a ladder bar car?

exwestracer
09-23-2011, 05:32 AM
Should be parallel to the axle as viewed from the back (level to the ground). Parallel from the top is not AS important, but you'd like it to be in that view as well.

Johnny Blaze
09-23-2011, 05:39 AM
Thanks, I knew parallel to the ground was important, just wondering more so about it when viewed from above. It is way off, per factory design, I can make some custom mounts to line it up that way, if its worth the effort.

exwestracer
09-23-2011, 02:46 PM
Anytime a straight link is out of square to the direction of force it imparts a side load to the components. It may not be worth a lot of effort unless you are driving it 10/10ths all the time. It was ok from the factory after all...

Johnny Blaze
09-24-2011, 07:15 AM
Anytime a straight link is out of square to the direction of force it imparts a side load to the components. It may not be worth a lot of effort unless you are driving it 10/10ths all the time. It was ok from the factory after all...

Drum brakes were ok from the factory as well, but as we all know here, some things that were ok in the 60's just aren't up to the task today.

I will not be driving 10/10ths all the time, but certianly will be pushing the corners much harder than was possible 40 years ago. I have done several mods to the truck already.

exwestracer
09-26-2011, 08:25 AM
Drum brakes were ok from the factory as well, but as we all know here, some things that were ok in the 60's just aren't up to the task today.

I will not be driving 10/10ths all the time, but certianly will be pushing the corners much harder than was possible 40 years ago. I have done several mods to the truck already.

Not exactly my point, but you are right, there is always room for improvement... Getting the bar parallel in top view will likely mean a longer mount on the axle housing, so make sure its well braced (same applies for the new frame bracket.

silver69camaro
09-27-2011, 06:30 AM
Drum brakes were ok from the factory as well, but as we all know here, some things that were ok in the 60's just aren't up to the task today.


Aren't we just talking about a parts hauler truck?

Anyway, if it were me, I'd try to keep the height of the panhard at the same height as the LCA's IC. That would prevent them working against each other, unless if the IC is too high. If the panhard is too low, it may benefit from a small sway bar if you have a large load in back.

dontlifttoshift
09-27-2011, 09:48 AM
Matt, that's interesting. So if the truckarm attachment point is say, 9" from ground you would want the attachment points of the panhard at 9" as well, or did I miss something?

silver69camaro
09-27-2011, 10:13 AM
Is the attachment point the true IC? If you draw a centerline down the middle of each arm, the IC is where those lines meet. IIRC the IC should be a bit a bit higher than the attaching points, but I haven't looked at one of those in a long time.

In theory, that's what you would want. Thankfully truckarms are very forgiving because packaging probably wont allow the most optimal placment, and it may not even matter because the truck probably wont be driving at 10/10ths.

dontlifttoshift
09-27-2011, 10:21 AM
guess I never thought of it that way, as far as instant center is concerned. Always assumed that attachment point was instant center.

Does the roll center height equal to instant center height apply to all solid axle rear suspension?