Rebuilding my rear suspension and looking for both lower control arms in nice shape, as mine are pretty dinged up. Want to get everything powdercoated, so need nice ones.
Also open to suggestions on if new ones make more sense, as I am running wider 335's in the back. Do I really need rear adj upper control arms?
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Many Pantera cars have too much negative camber and this will wear.out the inside of your wide tires quickly. Longer upper rear controls (or adjustable) can bring the camber back to zero. Slightly positive might be better. If your car already sits at zero then the longer uppers are not needed.
Also consider your toe. If all the shims are removed, and you still have toe out, you will have to have the adjustable arms to fix it.
Hello
i just got through customizing my 1973. I purchased the car in 1997 and it has sat in storage since the rebuild. All my suspension components are in excellent shape just needs to be powder coated. I’m in the Fresno CA area.
Hi Renegade, I sent you a PM
rrs1 posted:Also consider your toe. If all the shims are removed, and you still have toe out, you will have to have the adjustable arms to fix it.
Adjustable upper a-arms won't address toe, for that you need adjustable lower a-arms.
........Adjustable upper a-arms won't address toe, for that you need adjustable lower a-arms........
Can’t this also be done by adding/removing lower A- arm clevis-to-frame shims??
Larry
I believe it would affect toe. I have negative camber, and toe out, and all the lower shims are out. If I push the top of the A arm out to achieve excessive positive camber, then I could add shims back in to get neutral camber or slight negative. This would tilt the arm inwards to eliminate the toe out, and achieve a slight toe in if desired.
Somebody needs to make a batch of adjustable uppers, or some that are just 3/8" longer. I would bet a lot of Panteras need this.
Here is a surplus pair of upper rear adjustable a-arms that are gathering dust in my garage. They have an extra mount point for a road racing sway that could be cut off or left as is. The heim joints are in good shape, You are welcome to try them out and see if they work as planned. If you want to keep them we can work out a deal.
rrs1 posted:Somebody needs to make a batch of adjustable uppers, or some that are just 3/8" longer. I would bet a lot of Panteras need this.
The Pantera vendors sell both extended a-arms and adjustable a-arms, some adjust at the chassis mounting point others at the outer side and use a rod end in place of the ball joint. I have the latter on both my cars.
Checked with all the vendors except Wilkinson so far. They have none.
I will keep yours in mind Steve.
I called Wilkinson and Steve has adj uppers availible. He also said he will be offering new lower ones in 3/4 weeks at a much lower price. I am going to hold off on the adj uppers for now, and purchase his new lowers when available in a few weeks. Thanks for all the replies & input.
Did Steve say if the new lowers are direct duplicates of the original units or a different design?
Thanks,
Mike
I'm not sure about the design, but that is a good question. I'll have to call him back and ask. He just said they will be around 1/3 the cost of his current ones, but didn't give me an exact price.
For reference, below are what I have for uppers (Larry Stock part) with camber adjustment at the ball end. The upper a-arms don't benefit from a mounting side adjustment capability for toe as the upper joint is a degree of freedom, although you could force rear caster slightly with those if desired.
Does anyone here remember the arguments, twenty years ago, between Dennis Quella and Ted Mitchell over rear, upper control arm design? Ted maintained that the correct location for heim joints was on the inboard side. That way, the heim joints were in double shear not single shear and toe was then adjustable as well as camber. Dennis' response was by showing multiple photos of Indy Car upper control arms that were similar to his outboard heim joint design. In Dennis' defense, I'm not aware of a single failure of one of his rear upper control arms.
For those people interested in Ron Siple's rear, upper control arms, his e-mail address is: rasiple@aol.com. I have them on my Pantera and I believe George has them too. They're a bit more expensive than others but I can assure you, they're a work of art!
Dear David,
Yes, I remember that debate. It did happen just as you describe.
Warmest regards, Chuck Engles
I’m don’t prefer one design over the other but just to be more accurate the design with the spherical rod ends on the inside has the rod end bolts in double shear not single shear. The design with the spherical rod end at the upright is single shear. Double shear is always preferable. Single shear or double shear is really referring to the way the through bolt is supported. Single shear rod end design is commonly seen as outboard joints. Designed correctly and sized correctly they are perfectly acceptable. The load on the rod end is the same mounted either way as long as the fastener used in the single shear arrangement is correct for the job. One penalty for using rod ends with the fastener in single shear is that they are usually oversized to accommodate a fastener big enough to handle the load. My race cars typically used rod ends held between two tabs (bolt in double shear) for the inside points and a combo of single and double shear bolted rod end and spherical bearing inserts outboard. We never had a rod end or spherical bearing or suspension failure.
One penalty for in board rod ends is the potentially for a harsher ride. For my P-car I would choose the design with the outboard spherical bearing.
There are many grades and types of rod ends. The high quality ones can handle substantial loads if used properly. A friend of mine worked for a group that prepared Porsche 962s for US racing. From the factory the 962s came with sheet aluminum front bulkheads and tiny rod ends mounted with bolts in double shear. 8mm units. They would replace the bulkheads with machined aluminum ones and increase the size of the rod ends in some cases. Not that the factory design wasn’t strong enough but they were after better reliability. Their cars won many IMSA races and championships.
Mike
