Re-Greasing inside of Bilstein

[reachme]

Refreshing the front suspension on an 88 930. I've been doing well so far with lots of help from this forum but have some questions on regreasing inside of bilstein strut and the tech article is not clear on this.

1. This is not just a tube. Are there any tricks to get the new grease distributed properly inside the strut tube without overdoing it?




2. Is that fuzz and should I be putting grease below that or is that to stop grease?




3. I want to replace the factory pink stuff I pulled out with what is best/pink. I see threads calling for Rennline synthetic grease, high temp synthetic wheel bearing grease and Mobil-1 Synthetic Axle Grease but some of these threads (below) are 10 years old. Any updated recommendations?
Bilstein front strut grease type?
What grease for Bilstein F struts?




thanks for any help or pointers

[chris_seven]

DU Bushes are designed to run dry and the red assembly grease isn't very important.

I would just use a very light film of a standard LM grease on the body of the insert to aid assembly and leave it at that.

[3literpwr]

Lubrication is one of the main issues with the inverted monotube design. As you move your way up into inverted rally struts, many require frequent cleaning / regreasing as much as every event. Also, many have attempted to keeping the upper bearing lubed with creative means. I sell and service motorsport inverted dampers and if not for the added strength for rally, I wouldn't need them in my life. Note the Ti Nitride coating on bodies.

Older Bilstien motorsport units.

[chris_seven]

We used Bilsteins on our rally cars for years and never had an issue as long as the wiper was OK.


The GBB Data Sheet for DU shows that the bush gives better performance when dry.




Is the construction of the units you show different?

[Ferrino]

What are the DU bushes? Are they the two metal rings pressed into the strut housing?

[chris_seven]

They aren't a simple metal ring they are a low-friction bush designed to allow the body of the insert to slide in the strut housing.

They are manufactured by Glacier Garlock.

https://www.ggbearings.com/en/products/metal-polymer/du

They used to be about 40mm long but the latest bushes supplied by Bilstein are only 20mm long so we buy them directly from GBB.

[Ferrino]

Thanks Chris! Should they ideally be replaced when doing a Bilstein restore/revalve?

[chris_seven]

Only if there is play between the insert and the bush. They are a real PITA to remove.

Many people juts knock in a new top bush and leave the olds ones in place.

I don't like to do this and we have made tools to pull out the old bushes.