Jfrahm

Hi all,

I am investigating a handling problem on my 1992 968 and I am looking at the RF strut. The strut might be original at 160K miles but probably not, there is evidence of other front end work such as a new looking LF A arm with Porsche part stickers on it. The strut in question is a stock Sachs with the 951 part number. No evidence of leaking.

I have the spring and top mount / bearing off. The strut is difficult to compress by hand and takes 10 seconds to rebound from full compression. How does that sound? It seems to operate smoothly.

The bump stops on both sides are in poor condition and the dust cover cracked apart. I have replacement bump stops and boots on the way but I do not want to replace or hacksaw mod these unless I can be pretty sure I've got problems.

Any way of finding a date code on a Sachs strut?

Thanks,
-Joel.

Jfrahm

Anyone with a spare strut or insert they can compress by hand and tell me
1 - is this difficult?
2 - how long does it take to rebound?

Thanks,
-Joel.

Van

I threw some out recently... they compressed and didn't rebound at all.

Really, struts (shocks) fail a few ways. Like you mentioned, they can leak. But, also they can lose their gas "pre-charge"; the oil is hydroscopic (attracts water) and its properties change over time; and the seals in the "piston" which force the oil through the valving openings can fail so the oil isn't going in the route the designers intended.

For what it's worth, every time I *ever* changed shocks on *any* vehicle it was a noticeable improvement in ride quality. This includes shocks that were 40k miles old and ones that were 150k miles old. Shocks tend to fail progressively - and new ones are always better. I've never changed shocks and *not* thought, "That wasn't a worthwhile repair."

Jfrahm

Thanks Van

I have actually changed them on cars to no improvement once or twice. On cars with high pressure gas charged shocks/struts I have seen the ride height come up and things improve, but the sagging was a good clue that those were in bad shape. In one case I have had a car with underdampened 'floaty' old shocks that had nice damping after the swap. In this case I think I just have an alignment problem but I wanted to check out the struts while I am in there.

I realize it might be worth the $340 or so to hacksaw these but that would be a lot to pay for just a placebo effect and some peace of mind.

I wonder also if the Koni retrofit inserts are going to firm up the ride? I am happy with stock damping if it's working properly. If I wanted stock damping I might have to pay $500 for stock Sachs.

-Joel.

mytrplseven

I heard a clunking noise when driving out of my driveway and I thought I had a loose wheel or broken ball joint. It was actually the front left strut sticking in whatever position it was in. I pushed up and down on the front bumper on both corners. The passenger side responded normally and the drivers' side wouldn't move at all. That pretty much solved the point of failure as the strut. New struts and a re-align made it all better.

mel_t_vin

Joel, did you ever replace your dampers or did you just leave things as they were?

Jfrahm

The dampers (front struts) are fine, I just replaced the bump stops and boots. The issue was resolved with a steering rack and alignment. I believe the rack looseness shifting around under braking was my main problem. My car had a lot of front end work done before I bought it and it appears the struts are relatively new and working properly.

It'd be interesting to know the dynamics of new struts for comparison's sake, how hard are they to compress, how slow to rebound, etc.

-Joel.

mel_t_vin

Very true...same experience here.

Joel, I wish I would've taken some empirical measurements when I replaced my M474 front dampers almost 7 years ago.

From what I recall, I had to invert the shock, rod down, and really "lean" on the housing to compress it...and it compressed relatively slowly [I'm about 190 lbs]. I don't believe I could've done it, very easily, with just one hand.

Unfortunately, I did not measure the time it took for the strut to un-compress.

If anyone has, or will have, the -1038S or -1414S inserts laying around, waiting for their call to duty, would you please compress the strut and measure the time it takes to rebound? Thank you!