1st & 2nd Gen Lower Control Arm Bushing Alternative

[CTX-SLPR]

I've been working on a project that I started a few years ago thanks to a generous forum member who took a bunch of measurements of the front lower control arm bushing and it's frame sleeve.  What I've come up with is a not quite drop in replacement as the frame sleeve will need to be knocked out but a way to put a spherical bearing in that position to help free things up.  This will require a decent set of brake reaction rod bushings to control the fore and aft shift of the control arm since there isn't any rubber to mitigate movement in the bushing anymore.

The basic components are a machined steel sleeve that replaces the frame sleeve on the car, a spherical bearing retained in the center with a snap right, two spacers to allow the lower control arm to clamp onto the bearing like stock and finally a pair of seals to keep crud out of the bearing.  The spherical bearing can be any that meet the common "-12" spec but I've specifically speced out one with a PTFE liner in it for long life and a bit of cushion for impact.  I know in the rendering the spacer on the non snap ring side is hitting the lip, I will radius that corner since it shouldn't have much "run out" to need a large relief.  I plan to pack it full of grease after it's assembled but before I put the seals on.  Since I'm going to tack weld it into the frame I don't really want it loaded when I do that.

 

Now since I'm not a company or a PE, I can't really offer these for sale without a huge liability exposure on my part at this time.

 

I am also planning on addressing the brake reaction rod issue by replacing the rubber biscuits with a circle track ball joint that, unfortunately not as cleanly, requires opening up the frame hole to 1 7/8in since I don't feel the bearing that would fit in the existing hole would take the load that location sees.  This would connect via internally threaded rods (the type used in circle track racers) to a plate bolted into the stock rod location with an HD clevis pin to allow alignment adjustment.

[KongaMan]

I guess the first question would be why you want to "free things up".  The bushing, by design, is supposed to dampen the motion of the control arm.  If you replace that with a free bearing, is that not the functional equivalent of a torn stock bushing?  And how would you compensate for this extra motion?  Seem you might need to make changes to the springs and shocks as as well.

[DualQuadDave]

Love it! Sign me up for a couple sets.  I am going to work on a different front strut arm design that puts the strut arm below the control arm, not above it.  I work on a lot of slammed cars and the sway bar hitting the strut arm is a huge problem when you get low. I want to do that and work on a upper control arm that fixes the geometry issues. The car is so good from the factory, it really does not need much, just a little bit of modern tech to make it work even better.

[CTX-SLPR]

Most American cars of the era are under sprung, meaning the spring has too low of a rate causing the car to wallow and roll a lot.  The old bias ply oriented suspension in the new radial world doesn't help either.  I'm planning on putting either steel or air "coilovers" on the car to be able to play with the ride height and spring rate quasi independently as well as gain the adjustability of the newer adjustable shocks. 

 

I'm in the process of radically redesigning the front suspension but time and budget means I need to stick to parts that work with the stock control arms to begin with.  The control arms are really out of the question since the ball joints don't interchange with later stuff and I'm not in the mood to ream my spindles to match.  Additionally the spindles are way too short to work well with modern negative camber curve geometry.  The upper control arm is pretty simple, cut a stock control arm down to basically the bearing housings, weld on doubler plates to increase the thickness to 3/8in where the clevis pins will bolt through, then use a Howe/Afco modular upper ball joint collar ring to install a K772 upper thread in ball joint.

Bridge the gap with swadged tube or internally threaded tube to get your A-arm.  Near infinite adjustment as long as you keep the thread engagement high on the clevis and collars.

 

The lowers are probably going to be cut and extended lowers with either a hybrid K772 body with K727 stud or straight K727 ball joint collar welded into the stock hole.

Here's a rendering of my spindle with rotor and hub:

It's based off of a Coleman Modular design but uses a 2006-2010 Jeep Grand Cherokee SRT8 wheel hub that has been for my application ( don't like the SRT8 brakes or wheel options that clear the fixed calipers) redrilled for 5x130mm which is Volkswagen Auto Group SUV (VAG Touareg, Q7, and Cayenne) bolt pattern since that keeps the wheels and brakes matched together.  You can go from a basic 4 piston setup for 17in wheels (330mm or 13in rotors) to a 6 piston setup for 18in wheels (350mm or 13.75in rotors) to a crazy 410mm carbon ceramic rotor option that I think takes 20 or 21in wheels.  There's another option at 390mm but it's not as common so while I'm planning on using 19in wheels to keep the sidewall up but the tire selection good for performance (255/45R19), I'm not planning around those brakes.

Here's a Riv with what I think are the same size tires (not sure if they are 18's or 19's but 255/45):

[pyntre]

Wow..............

[jsgun]

I installed "Opentracker" front control arms on my 67 Mustang, and it made an incredible difference in handling, steering, and braking. Getting rid of bushing bind is a major improvement. It also made the springs and shocks much softer feeling. It handles bumps dramatically better. Downside is that below 30 mph, you feel every single pebble in the road, and there's a big increase in road noise.

 

Opentracker modifies Moog arms for Fords, he'd probably take on doing the same thing to Buick control arms. I used a swivel bearing setup from Calvert Racing on the brake reaction rods, and a bearing spring perch. The bearings seem to be a common off the shelf piece, because I replaced the brake rods bearings, for sealed ones from Summit Racing.

[KongaMan]

If that's the effect that you want, why not loosen the nut on the current bushing so the bushing rotates around the bolt?  It's a lot cheaper and a lot faster.

Edited January 21, 2018 by KongaMan (see edit history)

[CTX-SLPR]

7 hours ago, KongaMan said:

If that's the effect that you want, why not loosen the nut on the current bushing so the bushing rotates around the bolt?  It's a lot cheaper and a lot faster.

The main reason I'd not want to do this if you loosen the nut up, how are you sure it's going to stay on?  The inner sleeve is serrated and is likely to grip the arm even after you get it loose under even the most moderate torque needed to hold the bolt in place.

 

11 hours ago, jsgun said:

I installed "Opentracker" front control arms on my 67 Mustang, and it made an incredible difference in handling, steering, and braking. Getting rid of bushing bind is a major improvement. It also made the springs and shocks much softer feeling. It handles bumps dramatically better. Downside is that below 30 mph, you feel every single pebble in the road, and there's a big increase in road noise.

 

Opentracker modifies Moog arms for Fords, he'd probably take on doing the same thing to Buick control arms. I used a swivel bearing setup from Calvert Racing on the brake reaction rods, and a bearing spring perch. The bearings seem to be a common off the shelf piece, because I replaced the brake rods bearings, for sealed ones from Summit Racing.

I'm wondering how much of that you'd see on the Riviera since it's both body on frame with rubber body mounts and already has steel on steel upper control arm bushings in the front vs. the Mustang's unibody design with no isolators between the cabin and the suspension mounting points.  I'm hoping the PTFE liners in the spherical bearings help dampen it as well.

[KongaMan]

19 minutes ago, CTX-SLPR said:

The main reason I'd not want to do this if you loosen the nut up, how are you sure it's going to stay on?  The inner sleeve is serrated and is likely to grip the arm even after you get it loose under even the most moderate torque needed to hold the bolt in place.

 

The bolts on mine have a castle nut and a cotter pin.  Even if yours don't, replacing a bolt isn't that hard (and it's less destructive and reversible).

[jsgun]

7 hours ago, CTX-SLPR said:

I'm wondering how much of that you'd see on the Riviera since it's both body on frame with rubber body mounts and already has steel on steel upper control arm bushings in the front vs. the Mustang's unibody design with no isolators between the cabin and the suspension mounting points.  I'm hoping the PTFE liners in the spherical bearings help dampen it as well.

 

I suspect that most of the harshness was coming through the brake rod. There's ZERO fore-aft play in the wheel after it's installed, even though the bearing in the lca would allow it. The change in braking reaction was incredible. I think there could be a happy medium there, by using a spherical bearing for the rod, but insulating it using rubber. One mustang guy was looking into it, using TCP rods, but adding a rubber isolator at the front, allowing it a fraction to move. TCP's rod ends have plastic in them, but I've never read anything about them being smoother riding. Same thing using Global West's helm joint rod ends. Basically install a longer anchor bolt (that goes through the original rod's location) and isolate it with stock rubbing bushings. It would effectively get rid of the harshness, but you'd still have the free movement of a bearing. GW's stuff is stupid expensive, I think it could be replicated using off the shelf parts and competent welding for a fraction of the cost.

[jsgun]

On ‎1‎/‎18‎/‎2018 at 8:31 PM, KongaMan said:

I guess the first question would be why you want to "free things up".  The bushing, by design, is supposed to dampen the motion of the control arm.  If you replace that with a free bearing, is that not the functional equivalent of a torn stock bushing?  And how would you compensate for this extra motion?  Seem you might need to make changes to the springs and shocks as as well.

It's been my experience that removing the inherent binding allows the suspension to articulate faster, giving a much more responsive suspension. The brake reaction rod effectively triangulates the LCA, and there's no movement outside of it's engineered curves. It does put all the weight and force on the springs and shocks. My miserably hard springs felt considerably softer after I went to bearings in my ford. So much so, that I had considered going to stiffer springs. If I had gone to fully adjustable coil-overs, I could see it possibly to dial it into any level of handing wanted.