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View Full Version : Koni Shock failure, MK III IRS, Gordon Levy DAs



abloor
07-18-2016, 10:59 AM
Felt I should post my recent experience with a Koni shock failure. I built FFR 5809 Roadster with IRS. I chose Gordon Levy's DA Koni setup for my suspension. After 22000 miles my left rear shock failed at the rod connection to the lower shock mount just above the threaded section. I have been at the London Cobra Show for the last six years. The events included the legendary burnouts, some auto crossing, and two days each year on the Mid-Ohio Race track at elevated speeds. Fortunately my shock failed at low speed on an errand run at home. I contacted Gordon for the shock specifics and he sent me to Koni for a possible rebuild. He also suggested that I should try to determine why the shock failed (and I agreed). During the tear-down, I did not, unfortunately, pay particular attention to the setup as I felt that I could refer to my build manual. After sending the shocks to Performance Shock (Koni only recently disbanded their in-shop repair facility) I started my research on the failure.

In reviewing my build manual, I discovered a possible reason for my failure. On page 248 of my MK III build manual the specific instructions for mounting the shock to the lower IRS arms says in the text "10. Fasten the shock to the bottom mount with the fasteners and spacers provided. The longer spacer goes toward the front of the car." However the picture (labeled Lower shock mount) immediately following the text clearly shows the longer spacer mounted toward the rear of the car.

I referenced the pictures that were taken during my build and, indeed, I had followed the photograph provided in the build and NOT the text.

I contacted FFR and asked for clarification and was assured that the longer spacer DOES go toward the front of the car. I am of the opinion that this was at least part of the reason for the shock rod failure.

I am hoping that the word will get out to all of the owners of MK IIIs with IRS who are visual learners like me to check their lower rear shock mountings against the textual directions of the build manual.

Jim Schenck
07-18-2016, 02:43 PM
I checked our MKIII manual we have here on digital file and it has the picture with the same label (lower shock mount) on page 258. Is this different from the picture in your manual:
56331

Do you know what the Rev letter on your manual is?

Paparazzi
07-18-2016, 03:35 PM
I remember reading about this and having to change mine to be 'long forward':

87-95 Roadster Assembly Manual, Revision 2E

Text, p.254: "10. Fasten the shock to the bottom mount with the fasteners and spacers provided. The longer spacer goes towards the rear of the car."
Photo, p.255 clearly shows it to the rear.

Just checked mine (again) and have it to the front. Were the instructions just wrong?

Jim Schenck
07-18-2016, 03:49 PM
The earlier manuals show instructions for the Bilsteins which did have the spacers reversed from the Konis due to being the smaller bodies with 1-7/8 diameter springs. That switch occurred during the MKIII run so there are MKIII manuals out there with both versions.

2bking
07-18-2016, 05:53 PM
There have been several discussions about the spacers but I for one can say the shock will hit something at the limits of the suspension travel no matter which way the spacers are installed. The solution for me and others was to make equal length spacers to center the shock in the lower IRS arm.

abloor
07-18-2016, 06:11 PM
Jim,

56348

Well, I have tried to attach a photo of the page in my Build Manual. I must be doing something wrong.

My Build Manual indicates "87-95 Roadster Assembly Manual, Revision 2B. Page 248 of that manual contains the subject picture and text which conflict with each other. The advice over the phone today was "long spacer forward". Considering the Konis is this correct? I have experienced a failure of the right shock rod just above the threaded portion and the sleeve of left shock show some rubbing wear. I would certainly like to avoid any repeat problems.

Thanks for the help.

abloor
07-18-2016, 06:12 PM
Well I'll be darned there's the photo.

Jim Schenck
07-18-2016, 09:03 PM
Long spacer forward is correct for the standard Konis, I haven't seen a set exactly like you are using up close but a good idea to be sure is to bolt everything together with no springs in place and run the arm through the full length of travel to make sure there is clearance everywhere.

cChrisM
07-19-2016, 03:18 PM
There have been several discussions about the spacers but I for one can say the shock will hit something at the limits of the suspension travel no matter which way the spacers are installed. The solution for me and others was to make equal length spacers to center the shock in the lower IRS arm.

Agree with this, I took the spring off and spaced the shock so it would not hit the LCA in it full range of motion. I remember there was only a small sweet spot where it wouldn't hit.

CraigS
07-20-2016, 06:20 AM
Agree with this, I took the spring off and spaced the shock so it would not hit the LCA in it full range of motion. I remember there was only a small sweet spot where it wouldn't hit.
That is still the case. When you do this the shock moves in ways one would never expect.

abloor
07-22-2016, 01:12 PM
I was recently contacted by Performance Shock as to the rebuild of my shocks. The repair is on the level of a new pair of shocks. I was also advised that the oil in the shocks was very dirty which indicated harsh conditions. He suggested if my fronts were of the same time frame that there might be some attention needed there as well. I mentioned to the tech that I only pushed the car hard on occasions and had logged less than 25,000 miles. His response was illuminating in that he observed that the shocks were intended for racing and the typical service life was 10,00 miles or less.

cChrisM
07-22-2016, 02:00 PM
Holy schnikes Batman.......https://www.youtube.com/watch?v=ig4jbcU9db0