uncre8tv

(editing up front to note that this IS a common topic. Of course I feel my situation is special - the big answer I haven't seen is where to source new/good stock springs)

So, just in the thinking phase now - need to get it running reliably (ha - ok, regularly?) before I spend more - BUT:

I am currently running ~50mm low all around. I scrubbed and pb-blasted all around (let the blaster sit for 3 days) and still cannot move the front shock adjusters. They look stock (one is gray, one black, but they appear to look like the Boge's, and don't appear welded) but I broke a box-end wrench I was using as a lever on the adjuster tool when I tried to put a few feet of mechanical advantage to them. This tells me they're simply not going to move.

I'm also concerned that 50mm is pretty darn low and it might be as much a tired spring problem as an adjustment problem. The shock rebound seems fine when pushing on the corners, and feels ok when driving too.

What is the cheapest way to get stock ride back? Ebay'ing Boge's seems ok (have seen them for ~$150 per corner - would need to source adjusters) but I don't know what I'd do for springs. Not real interested in buying ebay used stock springs, cause they might be just as dead as what I've got.

I've seen a Koni setup with springs for a hair under 1700, which is rich but not impossible. The Bilstein setups I've seen are out of my range. And besides, I really just want a stock ride, not interested in anything firmer.

So - thoughts?

GlenL

Get new Boges. Take apart the coilovers you've got and clean the adjusters. Put it all back witht he stock springs. Adjust for the height you want. Done!

Hilton

The easiest way through the process is to buy a set of Bilsteins from Roger - they come with new adjuster nuts and perches (bilstein adjusters screw directly onto the shock body - they're slightly different thread dimensions to stock ones). Dismantle your old springs and re-use them along with the top perches and the Bilstein hardware. Job done. (although the lower perches that came with my Bilsteins were bare steel - so took a bit of prep.. I zinc plated them and then painted).

Boge or Koni shocks use the stock adjuster rings/collars; you'll need to either take apart your existing adjusters on the bench, or buy new/used ones to replace them with.

If you do try to remove the stuck adjuster nuts, do it while the threaded collars are still firmly stuck to the shock body (after you've removed the springs), so you can clamp the shock in the vise without damaging/bending the threaded adjuster collars. Once the adjuster nut is off, heat the threaded collar with a blowtorch and press it off the shock body.

6 months ago, although I was switching to Bilsteins, I had a go just to prove I could do it without the same outcome I'd suffered previously when switching to Koni's on a different 928.

I bead blasted the visible threads clean of cosmoline/corrosion/dirt, used lots of penetrating fluid, a blowtorch, an aluminium bar as a drift, and a big hammer, and managed to get the completely seized ones apart. Once you can get them to move, even a few mm, it gets a lot easier - just patience and lots of going back and forth adding more lube - but certainly not the kind of thing its worth paying a workshop to do at labour rates.. new parts are cheaper!

RKD in OKC

You do know you have to turn just the bottom nut to unlock them and not try to turn them both at the same time?

I have also had to use a punch (not the pointy one) and or dull chisel in the notch and a big hammer to get them unlocked from each other and started moving.

uncre8tv

Perhaps I'm missing something. Was wrenching with 2' of fence post on part number 11, in both directions, and didn't go anywhere. I don't see a lock nut?

uncre8tv

Thanks for all the replies. Seems to be consensus that 50mm too low isn't a sign of tired springs?

Hilton

Yes, that's correct - no. 11 is the adjuster nut. Commonly seized after years of being left alone with wet, dirt and sometimes salt.

I think by "both" RKD means the adjuster nut, and the collar it rides on?

dr bob

50mm lower than original height is pretty low for a street-driven car. My '89 was sagging so badly I couldn't make it into the driveway without scraping the nose. Plus as it sagged it was eating tires. I started out with the adjustment available, but after ten years of continuing adjustment I was to the point where I couldn't maintain stock height with the original springs. I swapped in a set of Eibach springs with new Boge, and set the front adjusters at max high just to get the car up enough to not drag going into the driveway (~~170mm). I pulled the rear Eibachs for a pair of new stock springs to restore ride quality. I have a pair of new CS/GT fronts to go in at some point, but the current setup seems like an OK compromise for the better roll control.

You may decide to remove the front assemblies, disassemble, and try to persuade the sleeves to move. 928 International will sell you good used replacement sleeves and adjusters for less than the aggravation on the old ones might be worth. Just sayin'.

Mrmerlin

save up the cash,
buy a set of Bilstiens,
and swap out your shocks.
NOTE when you measure the old spring heights from the bottom of the old shocks.
( before you take the shock apart)
From your info, you should screw the bilstiens up 5 turns,
this will move the lower perches up and raise the ride height,
that should put you in a good spot for factory ride height.

NOTE before you jack the car up measure the ride height following the WSM .

The Bilstiens are really good shocks and the car handles great at speed, the stock springs also work great with these shocks.

NOTE grease the threads on the shocks with a mixture of grease and anti seize as well as the lower perch to adjuster so it can slide.

Paint the lower perches with good paint or have them PCd.

' Use a generous amount of anti seize on the lower rear link pins,
roll them on a flat surface to check that they are straight

MFranke

Factory ride height is just a better all around ride quality. It is worth new shocks if your won't adjust.

Mrmerlin

MFrankie installing the bilstiens will include new adjuster collars and lower perches,
so you toss out the Boges and the crusty adjuster parts

axis of evil

Get some spring compressors and take some weight off the perches before you try to adjust, easy, with enough room on the front.and get a wrench you can really lean on.

GlenL

Get them out and take a look. The car could be lowered or the springs could have been torched, or cut down. It's unlikely that they've sagged 2" at each corner.