AWasserman

All,

I have been searching through threads, but the info is a bit here a bit there, and I am never quite sure if I am putting it all together properly.

Do I really need new springs or just new perches? Are the mounts the same is some adaptor needed. Everything I read seems to be about the front end, is the back end a straight swap?

So I would be grateful if anyone could help me with a simple checklist of what I need to do/buy to swap out my OEM Boge and put in Bilsteins? (1991 S4).

Thx in advance,
A

Hilton

I've done this swap with my 87.

Buy the Bilsteins - they come with adjuster nuts and lower perches (which are bare metal - so need to be coated with something).

You can re-use all the bits of your Boge suspension setup at the top end (springs, top perches/mounts, washers), although chances are the bump stops and front dust covers need replacing (possibly the rear dust covers too - but the fronts crack sooner).

edit: I can't remember if the top nut is the same thread - I have a large selection of various metric lock nuts so didn't reuse them.

One thing worth doing before you start - while the car is on the ground, undo the top lock-nut on the boge shocks, and replace it with a regular nut. It makes disassembling the shock/spring much easier once its all off the car if you're not fighting the lock nut and rotating shaft.

AWasserman

Hilton,

Thx for the help.

Have you checked ride hight? I really want to keep it to factory specs and I have read elsewhere that just swapping the Bilsteins in without changing the springs will raise the ride hight by a couple of inches.

A

Hilton

I had no issues with ride height on my 87 S4 - its currently set at 170mm front, 175mm rear, and I have room to lower it a little (its 5 full turns of the adjuster nuts up from the bottom at the front end - or 7.5mm of adjuster threads, which is roughly 15mm I can lower the front by if I wanted to sacrifice my spoiler in parking lots).

The springs are original S4 ones with 2 brown stripes on them.

Having said which, I know that Landseer had issues with ride height on his 84 when he converted that car to bilsteins and later suspension/brakes - so there's at least one case of ride height issues out there.

Landseer

My front ride height issue still doesn't make sense.
Am thinking there might be something out-of-ordinary with my particular set of front bilsteins.

The issue actually originated long before my suspension upgrade, when one set of bilsteins was swapped for a new pair.

Your swap will probably be fine.

Mrmerlin

before you jack the car up measure the ride height so you can some idea what you have VS what you need
report back your reading prior to swapping out the shocks

ROG100

Full set of Bilsteins including threaded nuts and spring perches $928 plus shipping

docmirror

Interesting pricing structure.

Landseer

Is also a fair price. The front threaded nuts cost me $99 each to replace.

jpitman2

The WSM says putting gas shocks on in place of non-gas may lift ride height 10mm IIRC. Mine had a factory M474 option, so refreshing the shocks just brought it back to normal. The original fronts did not have adjustable perches, but the replacements did.
jp 83 Euro S AT 55k

Hilton

If we say its too cheap, maybe he'll find another receipt and raise it

Oh wait.. that would be a different vendor