Suspension upgrade project using Rebel Racing bits

[Flieger]

Just for the information of everyone else, Clint installed my rear bushings in a single day, but I only had polyurethane ones to take off. Getting the rubber bushings off is what takes the longest. Clint started around 10AM and finished around 7PM I think, but that included talking with several people who came by, driving a friend to the airport, dealing with a very rusty torsion tube on one side, removing a timesert that had a broken tap in it (from a different mechanic) on that same side, and lathing the bushings to fit. Oh, and we decided to change torsion bars while we were in there and one side took forever to get the spring plate angle correct. One side took about 3 times as long as the other because of the rust, bolt issue (Having 3 bolts for the time being made it hard to bolt on the cover without causing binding), and the fussy spring plate. The other side only took a couple hours at most.

So if you have poly bushings in there you should be able to do the rears in one day, or at least one weekend. Just use the "JB Kwik" or whatever they call it. Sets faster than the normal JB Weld.

[gsxrken]

Yes, I could agree that just the spring plate bushings would be a day, albeit a long one.

I can report that Jim's idea of in-place banana arm bushing replacement is the way to go, or a way to go if you don't need to replace rear wheel bearings.

By loosening the trans mount, I could lever it over enough to get a 22mm offset wrench on the bushing through-bolt's nut. That allowed me to drop the arm from the body mounting ears, and pry off the outside of the bushing cover. This still leaves the inner bushing sleeve in the arm, but I was able to sharpen a chisel attachment on my air hammer and deform/destroy the bushing and then fish it out with a flat head screwdriver. Of course one needs to be careful of the soft aluminum arm:


As stated by Jim as well, after the one side is out, a socket that just fits inside the inner diameter of the arm can then be slid in and the inside bushing half can be pounded out.
I'm glad I went through the trouble... the bushings inside were deformed in a very similar manner to the spring plate bushings. The constant weight of the car over the years causes the rubber to compress in the weight bearing plane. It's somewhat apparent in this pic (old on left, new on right) but more so in person:


Getting the bushings in was simple too. Heat gun on the arm, white lithium grease in the arm and on the bushing sleeve, and then draw them together into the arm first with a c-clamp and then a final seating with the through bolt and nut acting on two huge washers I have. Actually the washers are the thick turbo tie rod spacers- I knew I would use them for something when I tossed them in the bolt bin! This pic is after the c-clamp but before the bolt operation:


I never did anything about plating the spring plate. It's probably going to flash over with some surface rust eventually.


Still have the Tarrett sway bar to do, and put the car on the ground to see where my ride height is at. I'm sure that will take a few attempts to get right.

And looking ahead a little further, what is the adhesive I should use to re-glue the vinyl rock guard to the wheel flare when I am done-done with this job?

[Flieger]

If you know your corner weights, torsion bar diameter, tire diameter, and the height from the torsion bar axis to ground I can give you a spring plate setting that ought to work. It will at least be close enough to only need minor adjustment with the spring plate.

I am assuming that the Turbo torsion bars are the same length as normal 911s, and that the spring plate is the same length.

[gsxrken]

Originally Posted by Flieger

If you know your corner weights, torsion bar diameter, tire diameter, and the height from the torsion bar axis to ground I can give you a spring plate setting that ought to work. It will at least be close enough to only need minor adjustment with the spring plate.

Thanks for the offer but I only have the rear of the car in the air so angles and measurements are all relative because the car is tail-high. I assembled the plates on the new 30mm bars at 2 degrees less than my baseline because I wish to drop the car slightly. It can't be too far off but who knows. I hear the new shocks can raise body height too.

[Flieger]

2 degrees is around 5/8". Stiffer torsion bars than what you started with will, of course, reduce that difference (or even reverse it).

[gsxrken]

Hey Max- do you know if the custom Bilsteins need the dust cover from the old shock? The newer shocks use a wider diameter thread and would require that I drill the old green cover so it slips on the new shock. They might rattle around too, since it appears the travel limiter is not as wide as the old one and thus would not keep the cover tight to the bushing.
If they are not required, thats fine. My vintage mustang has custom bilsteins as well and has exposed pistons for many years without ill effect. Thanks

[Flieger]

I am not sure, but I am leaning towards no. The only reason they would be needed on anything is to help keep dirt away from the seal but it sounds like the seal alone is enough for you. It's extra weight gone.

[gsxrken]

I thought I'd continue to document the suspension overhaul for those that might follow. I hit a huge bump in the road, had to rewind a bit, and then proceed but with rear coil overs.

I found that I could not assemble my LH side spring plate without binding. Meaning, as I began to snug up the four bolts that hold the outer cover, they got tight early (before the cover was tight to the threaded standoffs) and the arm was tightly bound in the bushings and would not swing. Here's a shot of the assembly as it was binding. Note the spaces between the bushings... they should just about be touching.


Unfortunately, my torsion bar's splines was holding my spring plate at a slightly different angle than the bushing cemented into the torsion bar tube. These bushings really do not tolerate any mismatch. My original rubber bushings were deforming enough that it wasn't an issue, but these one's wouldn't permit it without binding.


I thought perhaps I epoxied the bushing in at an angle, because without the torsion bar installed I could tighten the outer cover right up to the spring plate with no binding. If you have ever tried to remove the slow-cure JB Weld in-situ, you know what I went through. I had to crank up the acetylene torch and use an infrared heat sensor to determine when I reached 600*F and the epoxy would release. Well at 600*F, the amount of smoke, stink, and drooping undercoating is very alarming. I had the extinguisher and garden hose on hot-standby.


I did get it out but could not figure out what exactly was off. The hole is concentric as proven by my Starrett caliper, and nothing appears to be tweaked around it or on the torsion tube.


The whole job is of course on the cramped LH side where my Kuehl fender condenser is installed. No easy way to undo it all with losing my R-134 and that wasn't going to happen.

[gsxrken]

Additionally, during the course of the banana arm bushing R&R, I rounded out the brake line nut (despite using the proper metric flare wrench) attempting to undo it as I did on the other side. I should have snipped the flexible line and spun the end of it off the line nut, but I am beginning to forget half of what I used to know. So new brake line had to be made up, and I renewed the flexible line while I was at it. Hard line is NLA and auto stores have 20" and 30" lengths pre made, so it was off to a friendly shop to have them flare my cut-down 30" generic length.


Clint at Rebel sent another bushing and race at no cost despite my offer to pay at least shipping.
Prior to epoxying it again, I attempted to install it dry but with the torsion bar installed and I again could not snug up the outer cover bolts without bind. This proved, to my dismay, that I hadn't installed the first bushing race in incorrectly. Without the bar, the spring plate tightens up nicely without binding and without deflection, which is the whole point of these bushings, right? And it lines up nicely with the banana arm surface too.

So I could go back to new rubber bushings and not deal with it, or I could go with rear coil overs and take the torsion bar effect out of the equation. I was this far into it that I was not going to go back to rubber. Another call to Clint and he agreed to take the 30mm bars back in exchange for his rear coil over kit.


Luckily, the custom Bilstein rear shocks that I got from him have a groove in the body to also serve as the basis of the rear coil over snap ring for the coil overs. These were damped to match the 30mm bars, and Clint suggested I go with some 350lb springs on the coli overs to maintain the same wheel rate.

That's where it sits. My fears of tying up the car for prime driving season have fully been realized, due in part to this weird issue but more on my schedule. Blows, but the end is near and it should be a huge improvement.

[speednme1]

Getting close there my friend, are you eventually going with coilovers in the front as well or just leaving it like that for now?

[jwasbury]

Dang Ken, your suspension upgrade is being a PITA. Mine sorta went like that too. Turbos love the cool days of fall, so git 'er done and back on the road. Bring the car over to Monticello for some shakedown laps

[gsxrken]

A very belated set of updates to this thread follow:
I did end up installing the Rebel Racing rear coil over kit with 350lb springs.



Actually not shown is the little Eibach helper springs that I subsequently installed as well, since I found that the could spring was rattling around freely when the car was at full droop like it would be if you completely unloaded the suspension over the crest of a hill. That just didn't sit well with me, so off they came again and I installed the helper springs that take up that inch or so when and if it ever happens.

[gsxrken]

A few shots of the Tarrett rear sway ba and the mounts that also serve as one of the rear alignment adjusters:







One of the things with these, and any other anti-sway bars really, is that you need to take all of the preload out of them for an alignment and corner balance. I just put them roughly centered for the time being, as I've done no tuning yet.

[gsxrken]

One of things that dragged this on for so long was my DIY instinct, which really was misplaced here when it came to the alignment. I purchased the Smart Strings and Camber gauge kit and the amount of times the car needs to go up in the air, tweaked, driven a bit, and then reset up with the strings kit gets foolish for someone with my time constraints at the present.

[gsxrken]

New rims and ride height set a little too low for good handling:



I still am headed to Dan Jacobs shop in CT next week for a corner balance, ride height tweak, and final/final alignment.
July to November, yeah that went as planned...

[jsveb]

But dammit it looks good!

[speednme1]

Damn brother...she's looking ssswweeeetttt!

[spence88mph]

Originally Posted by jsveb

but dammit it looks good!

+1000

[full quack]

We now have almost the same set-up, but I raised my front spindles up 40mm & went with 23 /30 t-bars & wevo weld on rear sway bar mounts, 17 x 8.5 fronts & 18 x 11 rears.

Really surprised that Clint did not talk you into the raised spindles that as well.

Mine sits even lower than yours, and with all of the bits-n-pieces, handles superbly!

Mark

[gsxrken]

Thanks guys. Mark, your car sets the standard for stance as far as I am concerned. I'm an admirer.
I told Clint I was going for just a bit lower than euro and he said I'd be fine with stock spindles but if went too low I might want to get bump steer tie rods. I was also more than a little leery of sending mine out and getting hung out there from a turnaround perspective like some have... which is a bit laughable in hindsight as I was the long pole in the tent, not any supplier.

The car is already much more compliant. I have LESS NVH than I had before if one can really trust memory with four months in between rides. Brake dive much improved. I want to join the NY/NJ/CT run on Saturday after my CB and ride height and then final alignment at Dan Jacobs and I will have a full 300+ mile report.