Jchiodi

I am not happy with the way my 928 feels on the road. I have the adjustable height bilsteins, and have bilsteins on my 04 acura tl, a 90 volvo 740, and stock shock setup on my 944. They all feel better at handling the small bumps and rough roads in Ohio!

It was horrible before I replaced the Motor Mounts, and that did improve the feel dramatically, but I wonder if these shocks need to be rebuilt? As far as I can tell they are the originals, as are the springs. Your typical "bouncing" the corners of the car doesn't seem to give much input to me. It feels if anything too stiff, which would be the opposite of a normal worn out strut or shock.

What is the best way to check them out? I have the rears off right now since I was doing the repack on the rear axles.

If I have to I will send in to Bilstein for them to do the work, as far as I can tell it looks like a good option. Any one try that route?

THanks for any info...

jc

jpitman2

There is a test procedure in the WSM - IIRC, its compress fully against the gas, and measure something. At this age they will certainly be candidates for a rebuild. I had my rears done a few years ago, and it worked out well. I can drive across railway level crossings at normal speeds and get a firmish rumble, but its not at all uncomfortable. Note however that potholes and small sharp edges will always give you a sharp ride in my experience. When I had the rears redone it was economic as the genuines were quoted at A$600+, but the refurb cost was under A$200. The Bil agent quoted the same for doing the shocks on my Subaru GTB, which was very uneconomic against new units.
jp 83 Euro S AT 56k

jcorenman

How many miles on the car?

If they are Bilsteins, then I think it is unlikely that they are original. most shocks were Boge, and the "sports" option was red Boge's. Bilsteins with Eibach progressive springs were/are a popular retrofit. Take a careful look at the springs: If the coils are closer together at top or bottom, then they are likely Eibach's. If the coils are uniformly spaced, then likely stock. Stock springs will also have a colored paint stripe, Eibachs will have "928.intl" printed on them, both likely covered in dirt.

Eibach/Bilsteins are stiffer than stock, many folks like them and many others hate them for being too harsh. I am of two minds: Both our S4 and GT are fitted with that combination, the GT is just perfect-- firm and well-controlled without being harsh, while the S4 will shake your fillings out.

The difference is age and miles, the GT setup goes back at least 6 years and 100K miles (likely farther) while the S4 was recently fitted. I don't know if the springs have changed, Greg Brown thought that ours looked different than another set we were looking at.

We've driven a couple of cars with GB's favorite combination, Bilsteins and stock springs, and we like that setup very much. That's where our S4 is headed as soon as I get a few moments.

So have a careful look at the springs: If they are Eibach progressive springs then try swapping them for a stock set, if still too harsh then send the Bilsteins out for re-valving.

Cheers, Jim

UpFixenDerPorsche

Some years ago I fitted what I thought were something like Sport - Comfort Bilsteins.

Ohhh my heavens - if I thought stock Koni Reds were hard then these things took me to another level of pain.

After digging around I found that my versions (high pressure gas) had shaft stiction of 65kg (140lbs), meaning that before the shaft could even move, it had to overcome the sticky friction of the seal gripping the shaft of 140lbs.

This means you're going feel a minimum of 140 lbs bumping from every corner of your car on the slightest road roughness, and it only gets worse from there.

In my case it was a filling-loosening ride on good quality freeway.

Yet I've driven other cars with so-called Sport Comfort shocks and found them to be wonderful.

I've given up trying to work it out. Complicated Bilstein catalogues or indifferent suppliers?

Just find 'someone' with a good reputation and a Roehrig Shock dyno: tell them what you've got and what you want, and pin them to guarantee their work. The good ones will happily accept.

HTH.

Jchiodi

I am pretty sure these are oem. Symetrical spacing and width top to bottom.. they are laying on garage floor right now...

I really do not want to spend the $800-900 plus for the new.

I will check current info on bilsteins site.

thanks and i will try to remember to post what i find out.

jc

Bill Ball

Bilsteins were installed in some years. They can be rebuilt. Check with Bilstein US. It used to be a nominal amount...$65 per. They will custom valve them to your taste. I have run Bilsteins with stock springs for years and do not find them harsh. They are quite similar to Boge Reds in my experience.

85euro928

JC,
Have the Bilsteins rebuilt, it was the second best thing I did to improve the drivabilty of my car. Also, are the springs marked with dots of paint? If you find the springs marked with three green dots it means you have sport suspension and the car will ride hard (but corner great).

The Forgotten On

I have a set of factory original Bilstein shocks that I had rebuilt (pulled them off of a parts car).

They are very comfortable, especially when compared to the original non gas oil shocks I had on my 81.

I have 18 inch rims and find the ride to be firm, but very comfortable. It makes 400+ mile drives easy to do.

If yours are old, I recommend having them send to Bilstein and having them rebuilt. They are great shocks when working correctly.

danglerb

Not easy to find anybody with a shock dyno that is open to the public and/or reasonably priced. Some of the offroad places have them, but not really open to the public. Bilstein will rebuild them, but they also last I checked would test them for something a bit less than half the $65 rebuild fee, plus shipping.

Somewhere in my parts boxes I have a set or two of early factory Bilsteins, which look nothing like the golden current models. I figure eventually some owner of an early car will end up with them.

bureau13

Are there different "models" or part number for 928-compatible Bilsteins? Has that changed over the years? I'm always on the lookout for a used set that would fit my car, since they are rebuildable, but it's never been clear to me how to know which are right.

Jchiodi

Think this model bilstein, (at least on their website) are only compatible with 928's, almost all years.

Checking all over so far to determine best new price, probably about 900.00 at FCPeuro.com.

Price to do rebuild at Bilstein - Minimum of $300.00 for set, plus shipping, plus any unforseen extras.

Either way, ouch!.

jc

danglerb

Ouch, but not so much a Porsche OUCH, more a typical car ouch, way less than decent tires.

Jchiodi

But you're right, almost anything on the car costs and arm and part of a leg.

I had purchased a set of upgraded torque tube bearing from constantine, for about
$600.00! When I dropped the exhaust I noticed that the torque tube was replaced by PO in 2003, about 35K miles ago...

Now I wondering if I may try to sell them for $400-500 to help pay for the rebuild on bilsteins?

HMMM. always something

danglerb

My first lesson in Porsche ouch was asking my dealer about upgrading the shocks on my 81 around 1986, and my aging memory has their response as about $1400, a little more for the fronts.

Jchiodi

When I got my 944 my pass side ball joint and strut were bad. Parts at porsche $495. and 230. labor from porsche tech at his home garage another 300.

When I heard all this I found a kit to repair ball joint on control arm and an strut insert. total cost 100. did the job over a weekend myself..
never looked back......

love these forums.
jc