My 10-Year Suspension Mods

[Bill_VA]

So, after 10 years and almost 33k miles, I thought a refresh and tuning of the suspension was due. My goal was to refurbish and improve the handling components and make it all more “free” to move.

First step was to replace all the rod ends in the rear suspension. I pulled out the bars and carefully measured them and then installed new QA1 rod ends (see parts list below). I had replaced the rear lower control arms with Levy aluminum units a few years ago, so I left them alone (nice stuff BTW). If you’re keeping score, the entire rear suspension is done in rod ends, pretty much already as free as you’re gonna get.

The next step was the front. I’ve been wanting to convert from bushings and sleeves to rod ends on the LCAs for a while, so Craig S and I put our heads together and ended up with these, practically identical to what Larry Casey and Fast Freddie had done previously. In addition to making the LCAs more “free”, it also allowed me to move the whole wheel assembly in about 3/16” to provide a bit more clearance between the fender and tire. My body guy used a bit too much filler inside the wheel wells and rubbing was occasionally an issue. Craig has a nice jig that he used to keep everything where it should be and expertly welded up the tubing and threaded inserts. In keeping with my desire to bring the wheel assembly in a bit, after setting the rod ends to keep the stock dimensions, we gave the rod ends 2.5 turns to shorten them up.
http://www.humtech.com/4bill/2016-08-29 17.04.58.jpg
http://www.humtech.com/4bill/2016-08-29 17.03.43.jpg

I also turned my attention to upgrading/refreshing the UCAs too. I ordered new SPC cross shafts, delrin pivot bushings, adjustment sleeves (4” & 5”), and rebuilt the UCAs. Note that the newer shafts mount the pivots about ½” closer together than the FFR-supplied Mark III units. Note that I had to shorten the aluminum adjusters a bit to ensure I had room to adjust.
http://www.humtech.com/4bill/2016-08-29 17.04.59.jpg

In keeping with the theme of making things “free” I chose to use QA1 ball joints for upper and lower. The deal with the QA1 joints is that unlike OEM joints that you can just barely more by hand, these can be moved easily by one finger. They’re really for racing applications, but I don’t mind the extra maintenance and attention they might require when I’m only putting 3500 miles a year on the car. The upper ball joints went in nice a smooth and everything just works perfectly, so smooth in fact that I tapped the UCA for a set screw to hold the ball joint in place. The lowers, not so much. First, I ordered the wrong ball joints, I ordered the 1987-93 Fox joints. After figuring that out, the reps at QA1 were kind enough to send me the correct pins. The other cool thing about the QA1 ball joints is that you can rebuild them and replace all the internal parts, so replacing the pin took all of 5 minutes. You can do all that with everything still on the car. However, the lower dust boots provided by QA1 leave a lot to be desired, they’re kind thin, are held on by circular springs, and frankly are poorly designed. When the spindle pushes down on one side of the ball joint the boot slides down one side and comes up on the other side. No good. Fortunately, I had one of the old boots from the stock Moog ball joints and with a bit of convincing, got them on the QA1 ball joint and works great. To be honest, if I knew these lower ball joints were going to be such a hassle, I probably would’ve opted for a set of Howe Racing ball joints instead. I will say this, the tech support guys at QA1 were a great help.

Upper - good
http://www.humtech.com/4bill/2016-08-29 17.04.02.jpg

Lower, before spindle - ok
http://www.humtech.com/4bill/2016-08-25 15.09.50.jpg

Lower, after spindle - not good
http://www.humtech.com/4bill/2016-08-25 15.11.20.jpg

Lower, with Moog boot - good
http://www.humtech.com/4bill/2016-08-29 17.04.10.jpg

The one remaining part to free up some more was the front sway bar. The VPM sway bars are great, but the front bars don’t come with greasable bushings, and I could barely move them a year after installing them. I ordered a set of Energy Suspension sway bar bushings with zerk fittings. After installing and greasing, they move much more freely.

Here’s a list of all the parts I used:
SPC cross shaft: 93400
SPC delrin bushings: 92025
SPC adjustment sleeve 4”: 92045
SPC adjustment sleeve 5”: 92055
QA1 ball joint tools: 1891-106
QA1 upper ball joint: 1210-105
QA1 upper ball joint boot: 9034-107
QA1 lower ball joint (Fox): 1210-115
QA1 lower ball joint (SN95): 1210-114

Energy Suspension Sway Bar Bushings: 9-5158G

LCA mod parts:
FK Rod Ends high misalignment bushings: 12-10HB (4)
FK Rod Ends weldable threaded tube ends: 2808 (4)
QA1 rod ends: XMR12 (4)
AFCO jam nuts: 10140
McMasterCarr tubing: 89955K969
McMasterCarr tubing for spacers: 7767T74

Rear 3-link replacement suspension parts:
QA1 rod ends: XMR10-12 (2) and XML10-12 (2)

[Bill_VA]

Limited mileage so far, but by the seat of my pants, I can feel two things. First, steering effort is reduced, because the ball joints are so easy to move. Secondly, road imperfections don't seem as dramatic as before, as if the suspension is now allowed to do its job more freely now. Also, I don't really sense any added harshness in the ride, still race car stiff, but completely tolerable.

[RoadRacer]

So, after 10 years..

10 years! Congrats. That speaks volumes; I've never managed to keep one car that long. Even the car that I regret selling only stayed with me 4 years (2 years on the road). You must love it. Nice job on the updates too.

[smithbks]

Nice work Bill!

[skullandbones]

Hi Bill VA,

I liked your explanations of the suspension upgrades. I, too, have done some but need to go back and do additional work. One of the points of interest are the cross shafts. How did you decide on those? I remember seeing some discussions on that subject. Were those the best recommendation for avoiding the broken UCA joint? I have the FFR shafts (came with MKIII kit). I lube them frequently and keep an eye on them for any telltale signs of weakness. However, I don't think you get a lot of warning when they do fail. Also, what setup do you have for your front sway bar?

Thank you,

WEK.

[Bill_VA]

WEK, I chose those cross shafts as they were the only ones that SPC sells that fit the hole spacing on the frame. I saw a post that said the delrin pivots were superior to the other and went with those. The delrin bushings are made well and when greased the grease oozes equally from all the internal grooves. Looks like they'll hold up nicely. I would think that my yearly, every 3500 mile, checkup and grease will maintain them well. The sway bars are VPM, front and rear.

[CraigS]

I did those shafts and pivots also maybe a year ago. They are vastly superior to the old steel on steel setup. In addition to the locking up and binding from lack of lube the steel setup required a lot of careful selection of snap rings. We discovered years ago at autocross tech inspection that when loose, they feel just like a loose wheel bearing. The pivots end up sliding fore and aft on the shaft. I have a selection of snap rings in 4 different thicknesses that I found at McMaster. The grease used to ooze out at the joint in the snaprings so easily that I was never confident that it was getting spread throughout the contact area. As Bill says, when I grease these there are 6 little oozes (is this a word?) at each end of the pivot. Really well done grease channels.