Upper Control Arm Cross Shafts

[CTX-SLPR]

Howdy,

I'm looking for some help on upper control arm cross shafts. In an effort to leverage off-the-shelf parts I'm toying with the idea of moving the upper control arm mount on the frame up 1.5in and since the spindles are custom anyway, making them that much taller. The thing is that current spacing between the cross shaft bolts is ~8in and a quick glance seems like the off the shelf units are much narrower in the ~5in range. Because the stock cross-shaft on my Riviera is shaped like _/---\_ to go over the upper spring pocket, I don't think I'd get the strength needed by bolting a plate to the stock pickups points then having to be 1.5in narrower per side. It would get awfully thin in the / and \ sections, thicker plate would add a lot of weight and the spindle is already as tall as will fit inside the wheels.


What aftermarket shaft for the SPC style adjustable control arm above is the widest between the cross shaft bolt holes? A quick jaunt through Summit showed SPC 93470 being almost 7in wide but is there something out there wider?

Thanks,

[jarretts70]

I'm a little confused. Why do you want to raise the cross shaft? To improve the geometry typically you would want to increase the angle of the upper control arm. To do that you would lower the cross shaft, not raise it. Or keep the cross shaft in the stock location and increase the angle by using a taller spindle. That's a little oversimplified, but it's the general idea. Am I missing something?

[CTX-SLPR]

I'm completely redesigning the suspension to reduce scrub, slightly widen the track, modernize the camber curve, and make room for wider tires. Since no one makes parts for this car I'm left to my own devices. I would prefer to leave the control arm mounts where they are but then I'm locked into using the stock cross shaft and bushings (which are actually just treaded steel inserts in the stock stamped arms) and would need to figure out how to mount the eye ends of the tubes to that. The car is not a 10/10th type of vehicle so getting a decent set of parts off the shelf is worth a certain compromise. However if I'm going to have to use massively thick plate to make the adapters to raise the arms to use such parts... not really worth the exercise.

[jarretts70]

OK, I get what you're doing now. I'm not familiar with the Rivi frame, but I know on A bodies, F bodies, etc., the upper cross shaft mount is a pretty basic tab kind of deal welded to the top of the frame rail - it also serves as the upper shock mount. The factory frame rail is fairly flat at that point ( I just went and looked at my stock 1970 GTO frame). What about cutting the upper mount off a donor A body and welding it to the Rivi Frame? Then you should have a better selection of off the shelf UCA's to work with.

Of course, it would depend on the shape of the Rivi frame....

[MrQuick]

70-81 camaro upper shafts are wider than 5". Check Coleman, they may have a replacement cross shaft

[CTX-SLPR]

Riviera frames are way different:

See how the spring pocket and shock mount causes the cross shaft to have a __/-----\__ shape to it?

I'll check out Coleman to see what they have. Probably should call SC&C to see what they have as well for SPC stuff.

[Skip Fix]

So is it an X frame like the 58-64 Impalas? But a totally different upper and lower A arm setup it looks like.

[CTX-SLPR]

Yes, it's an X-frame but the front suspension is closer to the 65-70 Impala with a single lower arm and a brake reaction rod.

[71RS/SS396]

So is it an X frame like the 58-64 Impalas? But a totally different upper and lower A arm setup it looks like.

About the only thing the Buicks share with the Chevy is the fact it's an X-frame, even the rear suspension is completely different. My 61 LeSabre has a factory 3-link and panhard bar, the upper link is even adjustable to some degree.

[1BADBET]

I think 7" might be as wide as it gets. I have a 67 lesabre with CPP control arms, the lowers bolted in and I used the global west strut rod. The upper has narrower bolt locations so I was going to modify the mount much like you are doing till I did some figuring and ended up using the stock control arm mount and turnkng down the ends on the stock cross shaft to the smaller diameter for the impala Delrin bushings and used that since it was much easier and my cross shaft kicked up to clear the spring pocket too so it would be a real pain ..... but my plans have changed.... Now I have a brand new set of control arms, and slightly used dropped spindle and disk brakes for a 65-70 Impala I need to post for sale lol.

[CTX-SLPR]

I think 7" might be as wide as it gets. I have a 67 lesabre with CPP control arms, the lowers bolted in and I used the global west strut rod. The upper has narrower bolt locations so I was going to modify the mount much like you are doing till I did some figuring and ended up using the stock control arm mount and turnkng down the ends on the stock cross shaft to the smaller diameter for the impala Delrin bushings and used that since it was much easier and my cross shaft kicked up to clear the spring pocket too so it would be a real pain ..... but my plans have changed.... Now I have a brand new set of control arms, and slightly used dropped spindle and disk brakes for a 65-70 Impala I need to post for sale lol.

Tell me more about turning down the shafts and where you got the Impala bushings from since I have a spare set of upper arms and shafts to modify if needed. I'd need to get a hold of the cross shaft bushing holders still though. I need the adjustment of the SPC style arms since the whole suspension is so different.

[1BADBET]

I used the CPP upper arm that came with the Delrin bushings the hole was just too small for my stock cross shaft to fit in it so I just chucked em in the lathe and turned down the ends. If your gonna go use the spc arms just see what bushings fit it and turn the ends to fit, your front suspension looks just like mine so it should be pretty easy if the spc stuff is close in width. If anything it's probably narrower and you can shorten your cross shafts. If your going to do the lower arms global west makes a strut rod with heims that eliminate the rubber bushing and it's threaded for adjustment too.

[CTX-SLPR]

I used the CPP upper arm that came with the Delrin bushings the hole was just too small for my stock cross shaft to fit in it so I just chucked em in the lathe and turned down the ends.

Cool, I'll have to check on the availability of parts through SPC or SC&C to see what I have to work with and if there is enough room on the stock shafts for the needed hardware.

If your gonna go use the spc arms just see what bushings fit it and turn the ends to fit, your front suspension looks just like mine so it should be pretty easy if the spc stuff is close in width. If anything it's probably narrower and you can shorten your cross shafts.

The basics of the suspension are staying the same but I'm building my own spindles and moving the wheel bearings way outboard. This lengthens the upper control from 8.5 to ~14.25in and the lower from 17.625 to ~21.625in. I would have replaced the threaded rods on whatever other applications I pilfered them from anyway.

If your going to do the lower arms global west makes a strut rod with heims that eliminate the rubber bushing and it's threaded for adjustment too.

I don't like the Global West strut rods since the heim's point of rotation pulls the front pivot point out of line with the bushing on the main arm making it bind. I'm planning on using a ball joint or spherical bearing (see this thread: https://www.pro-touring.com/threads/...ction-Rod-Help) in the stock location since I can't get ridetech's cool ball separately for the strut rod and a spherical bearing for the lower control arm.

[1BADBET]

I was working on a "fix" for all the problems the aftermarket stuff I had when I finally said screw it, called up Ron and now I'm going to build a full chromoly tube chassis and new suspension. Better for me to start with a clean sheet than fix problems since I'm doing all the work myself, going to start after the new year hopefully so keep an eye out for my big Buick that handles like a C6 and seats six!

[dirty rick]

I think you will be happier that way, as that x frame has no torsional rigidity. It relies on the body to stiffen it up such as the body mounts will provide...(great for noise isolation). even if you installed solid body mounts the frame will still transfer suspension loads to the body eventually disassembling it if the loads are high enough. At the cost of a less than stellar handling car.

[CTX-SLPR]

I think you will be happier that way, as that x frame has no torsional rigidity. It relies on the body to stiffen it up such as the body mounts will provide...(great for noise isolation). even if you installed solid body mounts the frame will still transfer suspension loads to the body eventually disassembling it if the loads are high enough. At the cost of a less than stellar handling car.

My '64 Riviera is an X-frame, his '67 LeSabre is a traditional perimeter frame. Only the Riviera kept the X through 1970, the rest of the Buick fullsized lineup changed in 1965 to a more traditional perimeter frame. One day I want to build a hybrid perimeter-X frame but that is likely a decade in the future if it ever happens. I might build a set of extensions under the door jambs to put the load through the frame instead of the double reinforced rockers sooner though.

[Skip Fix]

Always wondered on the X frames if adding "out rigger" beams to tie together ends of the X would strengthen it some.

[CTX-SLPR]

Always wondered on the X frames if adding "out rigger" beams to tie together ends of the X would strengthen it some.

I know Olds had a hybrid frame (and leaf springs) during the X-frame era.

It also looks like it has a set of body mounts that I've been eyeballing adding on mine right in front of the rear tires.

In my mind it's just like some of the aftermarket frames :

[Skip Fix]

Central Texas sleeper? Where in Livermore-80-81 we lived over by the airport, saw some nice WWII planes being restored over there. Lawrence Livermore Lab?

[bdiamond]

Could you not cut the tall factory spring pocket/control arm mount off and use a flat plate and tubing spring locator/shock mount? Rebuild off that with the stockcar type upper control arm mounts and you could use any upper arm you wanted. It would let you use a spindle that wasn't overly tall too.