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New top front arms

edgeedgeMember
Today has been a “Drop tools & work on Pantera day”.
So John & I set about creating some new top front suspension arms to cure the lack of Caster issue.
Nothing new really, plenty of people have made new top arms for the very same reason.
But like everything we do, we had to do it a bit different.
We used some of the parts off the shelf here at Edge for our buggy suspension.
Such as the ¾” UNF rod ends, (chunky) tube inserts & “quick turn” adjuster housings.
The “quick turn” housings are to facilitate adjustment without having to pull the suspension arm apart.
Simply back off the jam nut & turn the adjuster sleeve nut which jacks the rod end in & out.

These adjuster housings are used at the forward chassis mount & at the upright.
At the upright I have used a Ford tie rod end that has a ¾” UNF thread & a 7 degree tapered pin.
(I think they may be the tie rod end from some sort of Ford truck?)
I machined up some little tapered insert sleeves out of stainless steel to adapt the Pantera upright taper to the 7 degree Ford taper.

Because there is a limit to the Ford tie rod ends angle the adjuster housing on the arm is kicked at 7 degrees to allow the suspension to go into full droop without stressing the tapered pin.
Still need to machine some spacers for the ¾” rod ends to suit the chassis mounts reducing down to 12mm.
Ordered some “Seals-It” boots for the ¾” rod ends to keep out the dust & dirt.

I’m hoping for 6 to 7 degrees Caster as the connection point at the upright has been shifted rearward by 10mm, (on top of the existing 2 degrees it currently has).
By adjusting the forward mount in & out it will have a small amount of Caster adjustment, (before it binds up) & the capability at the same time winding in & out the upright mount to set Camber.
Total arm length can be adjuster using all three adjustment points if required.

I have bolted in place to test for wheel to body clearance due to the increased Caster & to check it clears the shock at full droop etc,
Tomorrow I plan to re-install with the correct spacers, remove the spring & cycle through its travel & check it functions correctly.

Regards,
Tony.

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panterrorpanterrorMy 74 GTS
As usual, very nice work Tony. I really like the installed adjustability. Just wondering about wheel position in the wheel well. I seem to recall from other posts that you may be in the process of doing some body work. How have you found the 10mm shift in wheel center to affect wheel well fit and tire clearance? I ask because every time I consider addressing front suspension geometry I conclude I would also need to make lower arms (bias upright mount forward 10mm) as well so as to eliminate any rearward biasing of the wheel center…….and yes, with the flares on my car hung about the current position, tire size, and ride height it really is close enough that it would create some clearance issues for me at lock-lock and travel. On a more minor note, it also would noticeably position the wheel off center asthetically, but of course, in many stock Panteras, this is the case anyway. How does it all shake out in your car?

Best,
Kelly
edgeedgeMember
I bolted the arm in place, fitted the wheel to test steering clearance & its got heaps of room.
Thats with a 285/40-15 with a central offset 15x10" rim.
If you had wheels widened outward it could be an issue.
Yes, moving the lower arm attachment point forward would be good to even it out.
To be honest, with the wheels in the straight ahead position, its difficult to pick the top arm modification.
I went for the tubular look as the factory arms, (to my way of thinking) look to chunky & mass produced sheet metal.
The stock shape arms certainly don't do much for the asthetics of a sexy sports car.

Ultimatly I would have prefered to make longer arms, change the upright with more kingpin inclination & less rim offset.
But that will be much further in the future as already I have too many ideas for this car.

Make the arms for sale?
Maybe.
I will want to test first & see what the durability is like, how the rod ends stand up to street use etc.

regards,
Tony
edgeedgeMember
Another test install to make sure the upright ball joint does not bind & to test how much adjustment I have.
This shot shows the suspension arm pinned in place, spring removed so I can cycle the suspension.
This is in full droop.
Front arm adjuster wound out 12mm, rear rod end only wound out 4mm, (which increases caster + camber).
Adjusts fine without any noticable binding.
Using basic measuring gear it seems to be adjustable by 2 degrees caster on the forward adjuster.

regards,
Tony.

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edgeedgeMember
Thanks Johnny.
I'd like to ask you a question regarding the top arm modifications you have made.
How much did you shift the upper ball joint rearward?
And, when doing so, did you find the lower ball joint getting very close to its maximum angle?

My stock top arms had 6mm shims & i've shifted the ball joint back a further 10mm.
So the ball joint is pushed back a total of 16mm, (like having 16mm shims).
When I assemble I find I'm very close to the lower ball joints maximum rearward angle.
This is with the suspension at full droop.
I haven't popped the boot off of the lower ball joint yet to see if it's housing has a slotted hole surrounding the tapered pin.
(Some ball joints have more angle toward the centre position).

regards,
Tony.
bosswrenchbosswrenchMember
Tony, the upper rear ball joint is the only one of the 3 that has a slot-opening. The others have a circular opening, so no orientation problems up front. Note that adding screw-in zerk grease fittings to the ball joints and tie rod ends is one of the very first mods done to Panteras- back in the early '70s when they were new. Sure adds life to the assemblies and reduces steering effort.
edgeedgeMember
Thanks Guys.
So Bosswrench, that explains the lower joint maxing out if it has a round hole.
When it’s at full droop the lower joint would be at extreme angle in camber & the pin close to the edge of the hole.
As the joint approaches the centre of its position it should have more angle available in caster.

regards,
Tony.
edgeedgeMember
New lower front arms fabricated in tube.
Sway bar mount area is different as I’m running a Schroeder 26” .925” sway bar with splined ends & Aluminium lever arms.
The outer ball joint & shock mount area is much stronger than the original & the cap screw heads are recessed within tubular sockets.
Dimensionally the arms are the same as standard
Original arm weight is 3.25 kg each.
New arms are 3.00 kg each.
So not much weight saved, but a great deal stronger.
Regards,
Tony.

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