C531XHO

Hi All

Front suspension assembly is nasty so I have stripped everything off the car for a complete rebuild. Ashamed of this....



Part way through the exercise but apart from anything else, looking at changing my front lower arms as the bushes are showing signs of perishing and there is heavy corrosion of the metal sleeves. My car is an 85 with standard suspension (I think). The lower arms fitted are marked 928.341.413.08

I have been offered 928.341.413.06, will these fit as is or will I need different lower ball joints/clip etc?

David
1985 Euro S2

PS it's going to be such a good before and after picture when it's done!

The Forgotten On

the -08 ones are from an 86 or later. -06 are for 78-85 (early 86 US)

Do you have later 4 piston brakes? Someone may have upgraded the suspension in the past.

If you still have the original upper arms, hubs, etc you will have too much camber for a street car, perfect for a track car though.

Do you have a picture of the way the ball joints attach to the hubs? If they attach from the bottom they are early hubs, if from the top they are later.

C531XHO

Yes 4 piston callipers, not sure if these are Brembo or not (not marked) but stuck with them now as have had them rebuilt.

Unknown if the upper arms are original or not but they look as old as the rest of the suspension. Frustratingly I can't see a part number on the aluminium arm.

Balljoint attaches from below so early hubs?



I thought these balljoints were "too late" for my car but maybe it's running later suspension to allow 4 piston brakes?

C531XHO

...Oh also forgot to add, the 928.341.413.08 lower arms appear to show a casting date of Sept '84 in that sun/clock thingy on the casting above the Porsche logo. My car was registered in Nov1985 even though VIN suggests it's an '86 car..confusing!

DeWolf

Why replace the A arms when you can just replace the bushes?

FredR

That is one sad looking suspension system!

With a bit of luck the wheel carrier should be recoverable but the rest? If you look carefully at the carrier for the lower end of the strut you can see it has one notch in it- that suggests the car is fitted with the S4 LCA as does the wheel carrier so presumably the UCA is also of the S4 type. The earlier LCA is a bit longer and the support bracket has two notches in it so the arm you were offered is of no use to you unless you want to run with about -3 degrees of front camber.

If the lower arm beneath all that crud is usable, as Scott suggests a UK outfit called Powerflex do a bush kit for the lower arms and the updated version of this kit is due to be released imminently or so they told me last November when I was in the UK but I have no idea why the update was/is needed. You can also get bushes for the front UCA but at this moment in time the ball joint is not DIY rebuildable and chances are it is shot.

C531XHO

Thanks for the info Fred. I may opt to find a full assembly to swap out rather than doing it piecemeal. Lower arm aluminium is good, just the bushes and whilst I understand they ca be replaced, I am not convinced by the Powerflex route yet.

As to upper control arms, I was looking at a refurbished set from 928 International. Shocks going in the bin, springs ready for blasting and powdercoat. Callipers, discs and pipes changed already. Scored some nearly new lower balljoints second hand inc eccentric adjusters. Just need to confirm specs of the changing parts before ordering, I am mindful that if someone has changed components, maybe upper arms weren't swapped. Also have the crossmember out for powercoating and new mounts and have noticed that it has some welding repairs to both the crossmember and plate so maybe the car had some trauma on one side in the past. Although the suspension assembly is rusted to hell, the bodyshell/wheelwells are in amazing condition.

FredR

Its really not that difficult to change that lot out. I am open minded about the Powerflex option- have not had any feedback about how it works operationally speaking. Both arms can be rebuilt but then there is the cost to get the things back to the folks that do such.

Roger does an after market lower ball joint at very reasonable pricing. I am amazed at just how grotty that lot has ended up. The underside of my 928 is pretty much like it left the factory- needless to say no salt on our roads!

C531XHO

AHA!

For others trying to pick their way through this subject, I found a wealth of dimension/variation detail in the WSM Vol 4, sec 40-17 (it was there all the time but stupidly I hadn't looked) so will get the Vernier callipers out and do some further investigation...

Mrmerlin

FWIW you would be well served to find a crashed car with rear end damage and non corroded parts,
and swap as many pieces as possible,
from the looks of things just about everything thats made of steel has serious corrosion damage including the front suspension, cross member and swaybar.
I would think that spraying things with Waxoyl would have preserved all of if this

C531XHO

Thanks MrMerlin & Fred. Useful thoughts. Amazing what salt has done but at least is all stripped out now. Agree a straight swap is attractive and yes I'm a big fan of waxoyl!

Will keep you posted re progress

David

C531XHO

So further digging after reviewing the info in the WSM Vol4, sec 40-17 onwards;

1) Upper control arms show 215mm between pivot and ball joint centre and "kicked up" end rather than flat so 86 onward.


2) Lower arms show 179mm between pivot and inner balljoint/clip mounting hole so 86 onward.


3) Track rods show 235mm between back of balljoint adjuster nut and sleeve so 86 onwards.


4) Stabiliser linkage is type "B", marked part# 928 343 069 01 so 86 onwards.


5) Clamp and balljoint features and dimensions match MY85 "Modified version" but also satisfies the 39/26/~28mm dimensions shown in the new/current version diagram BUT my clamp has a single bead/indent (not 2 or none).
- Does this mean my car has been running the "wrong" balljoints/clamps do you think??
- Is there a geometry difference between MY85 modified version and MY86 onwards balljoints/clamps.

Wisconsin Joe

If the VIN shows it as an 86, then it should have the later, S4 suspension. 4 piston brakes tends to support that.

My understanding is that most European countries consider the "year" of the car the year when it was first registered, not the manufacturer's "model year". Typically, the model year came out in fall of the calendar year prior. So a MY86 could easily have been sold and registered in Nov 85.

"New" parts for cars that go through changes like this are often made quite a while before the changes actually appear on 'the street'.

ReDesign by FEATHER

The lower ball joints are the later version. They attach from above even though the nut goes on them from below.

C531XHO

Thanks Wisconsin Joe, I will program my mind when looking at specs for ordering. Just wondering if my suspension and brakes make the car an 86.5. What are the list of identifiers?

Thanks ReDesign - I see now, think I have found some later matching balljoints in the UK of the correct spec.