Reverting My SPC Upper Control Arms to Poly Bushings

TL;DR - I am not happy with the lifespan I got out of the X-Axis joints on my SPC upper control arms (UCAs), so I'm going back to the original polyurethane bushing-based SPC UCAs.

Like 1st, 2nd, and 3rd gen Tacomas, I think the 1st generation SPC UCAs (left) are the best. Change my mind.

I first installed SPC UCAs in 2018, 165,000 miles ago. Looking back, I'm not sure it was entirely necessary - I was able to get a perfectly good alignment with the stock UCAs - but it seemed like the right time, as I was significantly upgrading my front suspension after realizing how much I was actually using the Tacoma to explore the western United States.

Those SPC UCAs worked great until almost exactly two years ago. By then, 120,000 miles later, the SpecRide polyurethane bushings had worn out and were ready to be replaced. Since installing the first set, I'd gotten wind of a new joint - named X-Axis by SPC, but essentially spherical bearings - that replaced the SpecRide bushings on newer models of the UCAs. After a few conversations with SPC - where they informed me that the X-Axis joints were "lifetime joints" - I decided to take advantage of their upgrade program and traded out my original UCAs for a brand-new set that contained the new joints.

Unlike the first upgrade, the new SPC UCAs were anything but. Immediately, horror stories from other customers who'd installed the X-Axis based UCAs started rolling in. At first, I thought it was just a few outliers, but it soon became clear that the X-Axis joints were causing a lot more problems than the original SpecRide bushings. I was not happy with SPC. Still, they promised to stand behind the new joints, and I've been keeping an eye on them ever since.

It was about six months ago - at the end of February 2024, and 18 months after installing the new UCAs - when I started to notice a little bit of play in the X-Axis joints. I fired up my email and sent a message off to SPC:

Sent: Tuesday, February 27, 2024 7:06 PM
Subject: SPC UCAs with X-Axis showing some play

Hi ▮▮▮▮▮▮▮ ,

Hope you’re doing well. We traded emails a couple of years ago regarding some SPC UCAs with X-Axis joints that you did a “trade-up” with me on, from my original SPC UCAs with bushings. I’m starting to see some play in the X-Axis joints (a small clunk when I tug on the installed UCAs) and so it seems to me like the X-Axis joints are wearing out.

I’d like to trade them in to you guys under warranty - can you let me know the process? Would you like me to send a video of the behavior I’m seeing?

Thanks,
Dan

I got a reply back within a few days, and SPC asked me to send a video of the clunking that I was seeing, so I fired up my phone and sent along a poorly-executed moving photo of the situation, and awaited their response.

Being the middle of winter in the Pacific Northwest, I had to wait a few days, but eventually managed to mangle a short clip.

Sent: Wednesday, March 6, 2024 06:32

The bushing should not have any play at all. I could get them change with a core charge of $250.00. We are in a process of changing the bushing and ball joints in the next 4 months if you want to wait till then or we could do it now.

SPC Customer Service lead
Regional Sales Associate

After a few more back-and-forths to determine if I wanted to wait for the new bushings and ball joints, I decided that I would hold off on the replacement until I brought the Tacoma home from Las Vegas for the summer, and when summer finally did roll around, it was no problem getting a new set of arms from SPC, though the core charge had somehow ballooned from $250 to $525.

I'm Not Installing Those New SPC Upper Control Arms

I'd wanted to get the latest and greatest from SPC, because I had no plans to install them. Rather, I'd be selling them to someone else and wanted to ensure that they had something brand new and with better joints than I had.

My plan - after my dramatically different longevity experiences between the SpecRide-based and X-Axis-based UCAs - was to go back to SpecRide versions of the SPC product. As such, I'd picked up a used set from a fellow TacomaWorld member, along with five sets - enough to outlast the Tacoma - of SpecRide bushings.

And so, with three sets of SPC UCAs in hand, I set about replacement.

The first order of business - as always - was getting access to the front suspension.

I won't bore you with all the details of the arm replacement - anyone interested in that can check out my first installation, replacement with X-Axis UCAs, or even a step-by-step guide. Instead, here are a comparison of three generations of SPC UCAs and upper ball joints (UBJs) for comparison.

From left to right: the original tubular arms with SpecRide bushings and greaseable UBJs; the first generation of (stronger) cast arms with X-Axis joints and greaseable UBJs; the current generation of cast arms with updated X-Axis joints and sealed UBJs.

Comparison of the three ball joints, from oldest (left) to newest (right).

Comparison of the UCA bushings from oldest (left) to newest (right).

Wondering about the difference between the original and newer X-Axis joints, I wasn't able to get much information from SPC. All I was told was, "We changed the size of the bushing to fit better around the moonball." While this isn't very detailed, to me it sounds similar to the tightness rating that bearing manufacturers like FKS use when assembling spherical bearings. There, FKS has developed an "F1" tightness rating that is significantly tighter than normal bearings and provides a much longer lifespan as it keeps dirt and debris out of the bearing.

A comparison of the original X-Axis joints (left) to the newer variant (right). Visually, they are identical.

Replacing the SpecRide Bushings

With the comparison of the three UCA and UBJ variants complete, I set about prepping the oldest set - the tubular arms with polyurethane SpecRide bushings for use. This entailed removal of the old bushings and replacement with a set of brand-new SPC (25466) bushings.

Replacement bushing set.

Only a shop press (sometimes Harbor Freight is cheaper) is necessary for this operation, and I found that the instructions provided by SPC were significantly more complicated than they needed to be. To replace the SpecRide bushings, simply follow these steps:

Press out the old bushings

The old bushings press out of the SPC arms from the inside toward the outside. This means that a long press fixture is required, but luckily the Toyota OEM UCA hardware can be utilized.

Setup to press out a bushing.

1. Thread the OEM UCA nut "backwards" onto the OEM UCA bolt as far as it will go.
2. Place a large fender washer - with a ~1.5" outer diameter, just small enough to fit in the bushing sleeve - onto the inner side of the supported arm.
3. Place the UCA on the press, supported by one of the tubular arms and so that the bushing can be pressed out of the joint.
4. Slowly press the bushing out of the sleeve, being careful to watch for any flex of the UCA bolt, or interference/rubbing of the washer on the sleeve.

Repeat steps 1-4 for the remainder of the bushings.

Press in the new bushings

The new SpecRide bushings are pressed into the sleeves from the outside surface of each sleeve. Pressing in the new bushings is also a straight-forward operation and can be done with the assistance of the large washers that are supplied in the new SpecRide bushing kit.

Setup to press in a bushing.

1. Place the UCA on the press, supporting one of the sleeves so that the bushing can be pressed into the joint.
2. Place the bushing on top of the sleeve, with the small shoulder down toward the sleeve.
3. Place two of the large washers supplied with the bushing kit on top of the new bushing
4. Slowly press the bushing into the sleeve.
5. When the bushing bottoms out on the supporting surface, remove the UCA from the press and use a hammer or mallet to pound the bushing the final 3/16" into the sleeve.

Repeat steps 1-5 for the remainder of the bushings.

Putting Everything Back Together

With the new bushings installed, it was time to reinstall the tubular UCAs, adjust the alignment as best I could at home, and take the truck in for an alignment.

Reinstallation of the tubular SPC UCAs went smoothly, with lots of grease applied between the SpecRide bushings and inner metal sleeves.

After getting the arms installed, the next order of business was getting the alignment close enough so that I wouldn't need to worry about tearing up the tires, or that the alignment shop - Firestone in my case, since I have a lifetime alignment agreement there - wouldn't be able to get the job finished efficiently.

For this, Brett @Squeaky Penguin recommended that I do the following:

1. Max out the alignment cams. This means moving the cams so that the bolt is as far inward as possible on the front cams, and as far outward as possible on the rear cams. This maxes the caster.
2. Adjust the positioning of the UBJ using the large nut on the top of the SPC control arms to get camber as close to 90° (vertical) as possible.
3. Measure the toe, and if necessary, use the Outer Tie Rods (OTREs) to adjust.

Maxing out the alignment cams was easy. A 19mm and 21mm wrench were all I needed for this step, which entailed first loosening the bolt, then rotating the cam - from the nut side of the cam - and then retightening the blot.

After getting an alignment that you're satisfied with, make sure to mark your alignment cams with a paint pen, that way you can quickly determine whether a rough road has knocked your alignment out of whack.
Top: front alignment cams set "in." Bottom left and right: rear alignment cams set "out."

To adjust the position of the UBJ, I made a short piece of wood and attached my digital angle gauge. This allowed me to loosen - and then slowly move - the nut on the top of the UBJ until I got the angle of the wheel surface to a perfect 90°.

If you don't have a digital angle finder, get one. Or, you can use a short level, at the cost of accuracy.

To measure the toe, you can purchase some toe alignment plates, or you can make your own with a couple straight (being perfectly straight is important here) pieces of plywood. Since I was in a rush, I cut a piece of 3/4" plywood to be 45" long and 2.5" wide. To these, I attached to a couple of 8" tall feet, placing one against the outside edge of each of the front tires. Then, with the steering wheel centered, simply measure the distance from the outside edge of each board to the outside edge of the other. Ideally, they will be identical, and if they are not, you can adjust toe by loosening the jam nuts and adjusting the OTREs.

My toe was not perfect - the measurement was 3/16" longer in the front than the back - but was close enough that I decided to let the alignment shop adjust the OTREs rather than trying to do it myself.

And with that, I was off to Firestone for my final alignment.

That was a reasonable alignment at home, and the OTRE work was done quickly at Firestone for an overall nice alignment!

 

 

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