KASH '95 993

Upon installation of my ROW M030 suspension about a year ago, I discovered that the rear driver’s side ride height was approximately 3/8 inch lower that the passenger side (rear). I also did my TPC installation at the same time, so I assumed the additional weight of the supercharger on the driver’s side had something to do with the lower ride height.

With that assumption, I decided to remove the left rear shock assemble and shim it up
about 3/8 of an inch. However, upon removal of the shock I noticed that I might have had the upper spring perch installed 180 degrees out of phase (old spring impression vs. the new spring impression). The rear perch is tapered approximately 3/8 of an inch 180 deg apart.

Questions:

1. Would the upper spring perch being installed 180 degree out of phase cause my ride height issue?

2. Is there a preferred/ recommended method for shimming the rear spring/shock about 3/8 of an inch, if needed?

Any suggestion or speculation would be greatly appreciated before I re-install. Thanks.

Ken

viperbob

I am assuming that you have these on stock shocks? If they are more than 3 years old you should consider replacing them anyway especially with M030 springs.

With that said, the way to shim shocks it to replace the white plastic piece around the top of the rear mount. There is a 3mm, 5.5mm and and 8mm thickness. So first, check what you have. If you have the 3mm and go to the 8mm, this will raise the fender height about 10mm.

KASH '95 993

viperbob,

Thanks for the response...these were installed with M030 shocks. I do not have a white plastic piece around the top of my rear mount. The upper perch has a black circular crown pattern rubber (spacer???) that the spring presses againts that is trapered around from approximately 3/8 of an inch to 7/8 of an inch. And then there is the dust booth with a 1 inch browinsh rubber (bump stop???) at the end. Thanks it, no with white plastic at the top...???

Ken

jimbo3

I'm in the process of changing shocks- how are the rear spring top hats supposed to be oriented? Any way to tell if it's not right after installing? I've looked at them so much trying to get a handle on this that I'm dizzy and even more confused! Same issue as Ken- right rear fender is 1/4" higher than the other and the measurement points on the chassis show that the right rear side is about 4mm higher than the left, but I've been attributing that to the fact that the right front of the car is currently 6mm higher on the right, forcing the right rear to be higher, too. (Haven't changed out the fronts, yet.)

TIA- Jim

viperbob

Ken,

This is what you have at the top of your shock. It is the white piece of plastic that can be a little thicker for balancing ride height as I mentioned.

jimbo3

Is it even possible for the perches and/or "top hats" to be 180 degrees out? Looking at the OEM shock/spring/perch assembly just as it initially came out of the car, I couldn't come to a conclusion one way or the other. There is a high spot (approx 1/4") on one side of the assembled "top hat", but it was in a completely different position on one shock vs the other. Figured that, with any kind of weight at all, that spot would not be a factor. Seems to my like the "top hat" assembly was designed to more-or-less make the very top plate level (the one with the 4 screws) and it shouldn't matter which way it goes. All the instructions I've read, however, make it a point to orient the "top hat" assembly the same way it came out, but what specifically are they refering to?

-Jim

KASH '95 993

Hey Bob, that white piece is actually black on my shock tower...where is a good place to pick-up a 8mm unit ASAP? Thanks.

Jim, you can actually rotate and install the upper spring perch 180 degrees out of phase; however, I am not sure if it will affect the ride height.

Ken

jimbo3

Ken- How do you know if you're 180 degrees off or installed correctly? Are you saying that your spring isn't seated in the black rubber piece correctly, the perch isn't assembled correctly or that the completed assembly is 180 degrees out during installation? My rear springs/perches seem to be assembled correctly, but does it matters which of the two possible ways the assembly gets installed into the body?

FYI- The 3mm is 993 333 511 00, the 5.5mm is 993 333 511 01 and the 8mm is 993 333 511 02. The originals in mine were both 5.5mm (and white), leading me to believe that the factory may have used the 5.5's as the starting point, then raised or lowered a either side to adjust to within spec. Possibly the three thicknesses were made in different colors for easy ID, which could be why your's is black??

-Jim