Quote:
Originally Posted by N8N
Good morning all,
Finally got all my parts in the mail Friday evening, so today I'm trying to dry fit everything to the new shocks and struts to make sure I have everything before doing this for real. This is a set of Koni "Special Active" shocks for my E92 335i. I ordered them and a "cup kit installation kit" from ECS Tuning, as I'm pretty sure at least my bump stops are completely roached and I figure best at this point to start completely fresh. If there are some parts that are reusable to go in the spares bin that's fine but I really don't expect many.
So far between realOEM and a how to video I think I have everything figured out for the rears. The lower nuts included in the install kit didn't work because the Konis have a different thread but that's OK because they included Nylocs with the struts. (now the first rear I opened I believe had the nut for the front in it, so that was not reassuring, but the other rear had two nuts in it.) Unfortunately it looks like these won't get done today because I'll need to go to Harbor Freight and get some trim tools; I didn't realize but should have expected that I'll have to pull the trunk carpet.
In the same baggie with the lower shock mount were two nylon? washers with a split in them. What are those for? It almost looks like they could sit between the shock body and the bump stop? Don't see them in any instructions or exploded diagram.
BTW is it just me or is it weird to require diagrams and parts lists to install shocks? On all the old cars I've worked on everything has been completely self evident. I guess if I had the car on a lift it would be easier, but I don't - I'll be doing this in the driveway so I'm trying to plan around limited time and daylight.
thanks!
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The nylon washers have a couple different purposes...
They sit at the base of the shock shaft on top of the shock body, but below the bump stops.
Positioned here, they prevent the bump stops from creating a suction on the top of the shock body when the shock is compressed. That's why the washer is slotted. Air escapes and the bump stop won't have a suction/pressure on the shock body.
The nylon washers can also serve suspension packers. In this way, they're used to tune the length, effect, and action of the bump stops. They add a small amount of spring rate under certain conditions, by causing the bumpstops to come into play sooner (an amount equal to the height of the washer).
All of that being said, I don't know which of these reasons, or combination of these reasons, Koni includes them for in this particular E9x application. You'd be hard pressed to notice the difference between using them or not.
If you leave them off, you gain a small amount of compression travel.
It decreases your wheel (think spring) rate ever so slightly.
You may hear extra noises from the bump stops on rare occasion.
Include them if you want everything as Koni intended and have all of the pieces.
If not, you are not hurting anything.