128 rear suspension arms

Agnelli

True Classic
Rear brake shoes / drum refresh had been deferred on the 128 wagon. First failure observation was a big change in the parking brake function. Re-adjustment didn't reliably solve the fault. Replaced the quite old and likely original cable recently to no avail. Since the old rear arms had perished bushings, last year I had ordered new reinforced arms from Classic Performance, just hadn't gotten around to install. So it was time to work on the aft end of the car.

Removed and replaced rear arms, fairly straight forward as I had been in there before adjusting alignment. With the new arms and long plated outboard bolts, no longer needed shims fitted on either side of the lower strut housings. Bushing sleeves required only a slight adjustment.

On both left and right rear brakes, one shoe on each had the liners completely delaminate from the shoe itself. Replaced with new, OE Fiat shoes and likewise new OE Fiat drums.

arms x 3.JPG

Arm in situ.JPG
 

gene cooley

Autocrosser
Rear brake shoes / drum refresh had been deferred on the 128 wagon. First failure observation was a big change in the parking brake function. Re-adjustment didn't reliably solve the fault. Replaced the quite old and likely original cable recently to no avail. Since the old rear arms had perished bushings, last year I had ordered new reinforced arms from Classic Performance, just hadn't gotten around to install. So it was time to work on the aft end of the car.

Removed and replaced rear arms, fairly straight forward as I had been in there before adjusting alignment. With the new arms and long plated outboard bolts, no longer needed shims fitted on either side of the lower strut housings. Bushing sleeves required only a slight adjustment.

On both left and right rear brakes, one shoe on each had the liners completely delaminate from the shoe itself. Replaced with new, OE Fiat shoes and likewise new OE Fiat drums.

View attachment 46305
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Not sure if they are still available but the lowering "blocks" that I got from Al were actually blocks about 2" wide that provided some stability against the movement of the spring. Sorry I don't have any pics, they went on a friend's Yugo.
 

bark

Daily Driver
May I ask how are the arms reinforced? I'm fixing to order a pair of them. They look super nice!
 

Agnelli

True Classic
May I ask how are the arms reinforced? I'm fixing to order a pair of them. They look super nice!
If you look closely at the top image, showing the underside of the arm, there are reinforcements added to the inner sections of the arms. Gusseting that essentially doubles the thickness of the edges of the arms. If you look closely at the old arm removed from the car, observe the upper left corner - you can see how it's bent. This I think is the fault the reinforced design intends to prevent. Additionally, the modification seems that it would prevent the entire arm from twisting radially. If I recall correctly there's a post articulating one of our members having to sort through a pile of used stock arms to identify a single one that wasn't bent (shout out to Courtney here). The added weight is minor relative to the benefit. I will report on results after alignment and road tests.
 

Agnelli

True Classic
Rear alignment achieved at 2.5mm toe in right and left. Car tracks better with the new arms. It's perceptibly slightly stiffer, which could be attributed not only to the arms but concurrent swap to 124 steelie rims and Michelin Defenders (before the arms swap, alloy Compomotives with General Altimax tires). Next step will be to swap the front wheels also to the steelies/Michelins and make a slight front alignment adjustment. Toe out in front is correct, but will turn both front tires a hair left, though not until I install the new front wheels and drive it first to rule out any slight right pull attributed to the Altimax tires.

Definitely pleased with the new arms and their new bushings. It needed to be done.
 

Agnelli

True Classic
Steelies/Defenders installed and driven. Alignment is very good no further adjustments needed. Riding well no vibration or pull. Suspension finished for the present and ready for the 1600 big block as the next step.
 

bark

Daily Driver
Great news! I received notification that my reinforced rear control arms left Zagreb a couple days ago. b-
 

Lowtechprime

True Classic
You got the reinforced arms, but didn't get the nylon bushings for them? The bushings make a much bigger impact than any flex the arms might have.. I installed the bushes when I restored the rear arms. Much more planted and tight. Now the arms only move up and down, instead of wiggling around while cornering!👍🏼
 

Agnelli

True Classic
You got the reinforced arms, but didn't get the nylon bushings for them? The bushings make a much bigger impact than any flex the arms might have.. I installed the bushes when I restored the rear arms. Much more planted and tight. Now the arms only move up and down, instead of wiggling around while cornering!👍🏼
Correct. Good to know- will consider the bushing upgrade in the future. Any ride quality compromise?
 

Lowtechprime

True Classic
Nope... But to be honest, I have never noticed a difference in noise or harshness when changing from rubber to something firmer in any of my cars...(urethane or delrin usually) I honestly don't know what those people are on about.. The 128 isn't quiet like a modern, heavy, insulated luxury sedan to start with so....
I would rather the car be well planted going through the twisty bits! If you're worried about the noise your bushings are transmitting from the road, your radio (or exhaust) isn't loud enough!😁
 

Agnelli

True Classic
Nope... But to be honest, I have never noticed a difference in noise or harshness when changing from rubber to something firmer in any of my cars...(urethane or delrin usually) I honestly don't know what those people are on about.. The 128 isn't quiet like a modern, heavy, insulated luxury sedan to start with so....
I would rather the car be well planted going through the twisty bits! If you're worried about the noise your bushings are transmitting from the road, your radio (or exhaust) isn't loud enough!😁
Feedback appreciated. My X sounds like a sportbike (4/1 header) and the 128 will soon get the same vintage Faza 4/1 treatment, though it's already loud w/ 4/2/1 to Supersprint to Ansa system, no door panels, no carpet, floor insulator dry iced out and rattles like a can of rivets in an industrial dryer. Haven't had radios in years but willing to try.

It'll be interesting to see if the aural perception can be differentiated from road vibration. 128 front end has Ritmo lower arm bushes and stock strut tower bushings. When I renewed the front end I left the forward inner sway bar bushes alone: wagon 21mm bushings were difficult to source. That said, Classic Performance is sending a set of their aluminum block / delrin mounts so the experiment will begin.
 

Lowtechprime

True Classic
I have his front setup.. The Delrin/Aluminum sway bar mounts and the spherical jointed lower arms. Lowered about 2 inches ..I felt the handling was night and day from rubber bushed/ stock height. + Sticky tires of course! Toyo R888's. It's one of my biggest pet peeves at every car show, some people build an aggressive car, modify the suspension etc.. And then slap some Federal's, or General's, or some other cheap tire on it! Tires make the most noticable difference in the handling IMHO.... I know my modified Datsun 1200 Coupe can draft behind a Subaru WRX though a twisty mountain road, and a 911 couldn't stay with the 128 on the same road, and both were still a fairly comfortable cruise home... That's all I care about!😁
 
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carl

True Classic
I'm guessing most custom cars are for looks and they are not actually taken to track days. The Federals do have a very aggressive looking tread pattern.

A buddy of mine liked to tell me the story of him having his tricked out Corvette and got passed in a turn by his friend in a Buick station wagon. This was back in the 1960s and the Buick driver was a team driver for Group 44.

When I started doing track days, my street driving got much calmer.
 

Agnelli

True Classic
I have his front setup.. The Delrin/Aluminum sway bar mounts and the spherical jointed lower arms. Lowered about 2 inches ..I felt the handling was night and day from rubber bushed/ stock height. + Sticky tires of course! Toyo R888's. It's one of my biggest pet peeves at every car show, some people build an aggressive car, modify the suspension etc.. And then slap some Federal's, or General's, or some other cheap tire on it! Tires make the most noticable difference in the handling IMHO.... I know my modified Datsun 1200 Coupe can draft behind a Subaru WRX though a twisty mountain road, and a 911 couldn't stay with the 128 on the same road, and both were still a fairly comfortable cruise home... That's all I care about!😁
Helpful. Two follow up questions: (1) Re: the spherical jointed lower arms, I see they're adjustable. What function does that adjustment effect? (2) What strut set-up are you running with those arms?

I agree with you completely about tire quality. Are your R888's 185/60-13? Thanks in advance.
 

Lowtechprime

True Classic
Hey! The adjustable arms adjust camber, but I got the non-adjustable ones since I have adjustable strut tops... Right now, I'm just running a stock strut with a cut down spring while I finish my Koni adjustable coilovers. Yes, the Toyo's again for now are 185/60R13, but I'll be moving to 225/45R13 and flares after the front and rear coilovers are on.. If you do get R888's, make sure to get them heat cycled. They will last MUCH longer! Either do it yourself, or if you get them through TireRack they'll do it for you for a small fee. It's better to get them to do it to avoid the hassle, plus they put em in a machine that cycles them more evenly then you could ever hope to do on the street.
 

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Agnelli

True Classic
Hey! The adjustable arms adjust camber, but I got the non-adjustable ones since I have adjustable strut tops... Right now, I'm just running a stock strut with a cut down spring while I finish my Koni adjustable coilovers. Yes, the Toyo's again for now are 185/60R13, but I'll be moving to 225/45R13 and flares after the front and rear coilovers are on.. If you do get R888's, make sure to get them heat cycled. They will last MUCH longer! Either do it yourself, or if you get them through TireRack they'll do it for you for a small fee. It's better to get them to do it to avoid the hassle, plus they put em in a machine that cycles them more evenly then you could ever hope to do on the street.
Makes sense given the geometry: adjusting the inboard sleeves changes camber. I can see the advantage of the non-adjustables you are running - the inboard bushings unlike the adjustables have conventional bushings, but you get the key advantage of the lower arm center bushing improvement on your racing arms. Definitely a future consideration for me given your real world report. Can you elaborate on your coilovers? Curious to know which strut / insert and which springs. You schooled me on the heat cycling treatment, good to know. I'm planning to acquire some DOT Hoosiers next month 185/60-13 to test.

Your work is enviable. Clean, no expenses spared. You've got a 5 speed, so, is your front sway bar 19mm?
 

Lowtechprime

True Classic
The arms have a spherical bearing at both points.. with a grease cover.. I've run them for 4 years, they are awesome. I just rebuilt them, but they were a previous generation that didn't have the grease seals.. I also bought a second pair of the newer style..
The struts are a little elaborate.. The ones from MWB are probably great, but my weird brain doesn't trust the butt welded on mounting tabs.. Plus they don't make rears for the 128.. I wanted to use the stock strut mounting, but they are too small in diameter to fit a decent insert in, so I machined off the mounting tabs from factory struts, and I got Andrea from Classic Motorsports to machine up some bare threaded housings. The mounting tabs were not large enough in diameter so I sawed through the back, made blocks to keep the fixing locations unchanged, made a drift of the right diameter, and used a press to enlarge the tube portions! Then it's just weld them up..
The camber tops are rapid prototyped right now, but will get cnc'd in aluminum. The spring top plate has a built in thrust bearing and I'm using Hyperco 300lb. Springs. That was Matt Bannon's suggestion as a starting point spring rate, it will have to be dialed in.. I'm not saying that this is the best way, it's just what I did😁
I'm using Koni 8610 inserts, the short one's in the front, long one's in the back..
Sway bar is the 19mm standard 5 speed...
I would warn you off the Hoosiers for a street car.. I had got some 10" DOT's for my Mini, and they got hard and the sidewalls cracked from sitting in the garage (in opaque bags) in less than 3 months.. They're really just bought and mounted like a few days before a race weekend.. Conversely, I had a set of Toyo's on a car for 3 years of street driving + a few track days and they still had a tattoo of the tread left on them a were still gummy enough to dig your fingernails into.. I ended up giving them to a friend for an autocross event. You really can't beat Toyo's rubber compound, sticky down to the cords!
 

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