Lamborghini Jalpa
Suspension Struts

Another solution with Koni inserts 8610-1437

I just completed my front shock installation as the picture shows.

As previously mentioned I wanted to install Koni’s 8610-1437 one-way adjustable shocks in the front and got them early this week. The removal of the struts were easier than I thought, especially since both tie-rod ends separated with little convincing.

Once the struts were out I was surprised to see that they actually worked, except for some internal scraping and the rod was precessing 3 mm when rotated. They functioned well enough to assess their characteristics, which as very soft in compression and maybe twice as hard in rebound. The original shocks used the McPherson tube as the outer fluid container while the Koni I a self-contained insert.
The Konis were slightly harder in compression (non-adjustable) and I adjusted them proportionally harder in rebound (1.5 turns from softest towards firm).

The bellows were dead and I was unable to find a good substitute (so thanks Mike for the reference for next time “I am in there”) and the bump stops were crushed due to my sagging springs.

The fitment of the Konis was close but not perfect. It needed a ½” spacer in the bottom and some machining on the cast iron fitment ring (OD from 44.0 mm to 42.2 mm) and inside very lower section of the large compression nut (from 42.4 mm to 44.0 mm). With that done the fitment was near perfect.
The top threaded part of the rod was barely long enough, but fortunately the low-profile nut supplied by Koni worked well.
Koni had also supplied new bump stops which were installed.

Unfortunately I too late realized what the reasoning behind the recommended filling of the strut with oil was, so I installed the cartridge dry. As it turns out the oil acts as a thermal conductor, meaning that I probably should not take my Jalpa to the Baja rally, or participate in exhaustive track events until I get the struts filled (and a bellow installed).

As can be seen in the “installed” picture I had also made some 1” spacers to compensate for the sagging springs. There is also a (two-half) ½“ spacer ready to be installed if needed. Underneath the dirt and undercoating the parts were almost as new (no rust) so I left it alone in spite of the questionable presentation.

The whole process took two work-days and if no spacers would be needed the insert change can be done in 4 hours by a trained person.

By the way www.paragon-products.com (Jason) has a few Koni sets left if anybody is interested.

Thanks to Laust Pedersen

Also to be found on Lambo-Talk

Rear Struts:

Okay so I have the rear struts complete. I have not had a chance to road test because the weather is not great in Chicago. You can see from the images below just how bad they were. If you have a bit a mechanical knowledge and access to a drill press you can do them both for around $100.

I ordered 2 Monroe SensaTrack strut cartridges (#73264 @ $44 each) and two monroe Bellows and bumper kits (#63619 @ $14 each)
Here is a quick overview of the process

1. remove the strut assembly
2. Compress the spring with spring compressor tool
3. Remove top retaining nut
4. Remove top strut mount and spring plate
5. Screw off the strut cap (I used a pipe wrench which worked well)
6. Gently pry up the inner seal. ( this exposes the inner tube)
7. Lock the top shaft in a vise and Gently tap on the lower spring mount to unseat the inner tube.
8. Dump out the remaining fluid and clean the interior and exterior
9. The Strut cap needs to be machined to make the opening for the shaft a bit bigger. Also the inside of the cap needs to be machined to cut down the inner "fingers" (I cut them down by half of their thickness) .
10. The top spring plate and upper mount need to be drilled out to be 11/16. I used a 5/8 bit and honed it the rest of the way. ( I am not certain of the strenght. This removes a third of the wall thinkness) It seems to be strong enough at this point.
11. Now insert the strut cartridge and tighten down the strut cap.
12. Reverse the order to reassemble.

(side note: I cut down the bumper to allow a bit more travel and allow more room to put the top spring mount and upper mount on)

Thanks to David Enger of Chicago.

Also to be found on Lambo-Talk