Bilstein Question

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1Fine40

1Fine40

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This is probably something I could look up, but I did not find an answer on the Bilstein web site, so here goes...Does it matter which end is mounted up on a 5125 model? I'd like to mount the tube upwards, and the rod downwards if that is o.k....seems to me that it would protect the seal a bit better...

Thanks for any ideas/experience here.

Cheers!
 
John Smith said:
Considering how they are valved, unless you want to run them upside down the can should be at the top. Bilstein
Click to expand...

I must be stupid....where does it say what position to run them on the Bilstein web page you noted??
 
1Fine40 said:
I must be stupid....where does it say what position to run them on the Bilstein web page you noted??
Click to expand...

I doubt it does. Look at the writing on the Bilstein shock itself, if you install it can down the writing is upside down and therefore installed upside down. They made it super easy for you.
 
Thanks, It pays to look at things right side up! Anybody know of a good place to buy these Bilsteins??
I'm seeing that they are spendy units...

Cheers
 
I just recieved 5100's from a guy in the know at Bilstein:), and I had the same question. He informed me that the Bilstein's design absolutely allows the shocks to be used in either orientation. I put the silver side up on the front (matches label on shock + plus looks better IMOP) and the silver side down on the rear (again looks better....) and have been totally impressed w/ the difference.

65 FJ40 SBC 350 stock springs + 1" lift shackles F&R

:cheers:
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Last edited:
red65FJ40 said:
I just recieved 5100's from a guy in the know at Bilstein:), and I had the same question. He informed me that the Bilstein's design absolutely allows the shocks to be used in either orientation. I put the silver side up on the front (matches label on shock + plus looks better IMOP) and the silver side down on the rear (again looks better....) and have been totally impressed w/ the difference.

65 FJ40 SBC 350 stock springs + 1" lift shackles F&R

:cheers:
Click to expand...

If the guy at Bilstein told you that you could run the shocks either way then your 5100s must be valved the same on compression and extension. That is not the case with the 5125 model the original poster is asking about. Those are valved very differently for compression and extension. Check the link I posted to the Bilstein Web site.
 
John
:hhmm:Compression and extension force/velocity (valving) is always different regardless of the shock design/manufacturer;) this is not dependent on the orientation of the shock though, compression is always compression regardless of which side is up.

unless i'm missing something with the way the valve is actually designed so that it needs to oriented relative to gravity, but i doubt it...

Here's Kevin at Bilstein's response to my question:
the shock can be mounted in any position including horizontal because of the mono-tube design and it has no effect on the damping rate ( not so with Sachs) . In most racing applications it is preferable to mount the cylinder up because this reduces your unsprung weight. This is a critical factor on super light suspensions or 200 MPH Land Cruisers. Glad they worked for ya!!!


:cheers:
Ames
 
red65FJ40 said:
John
:hhmm:Compression and extension force/velocity (valving) is always different regardless of the shock design/manufacturer;) this is not dependent on the orientation of the shock though, compression is always compression regardless of which side is up.

unless i'm missing something with the way the valve is actually designed so that it needs to oriented relative to gravity, but i doubt it...

Here's Kevin at Bilstein's response to my question:
the shock can be mounted in any position including horizontal because of the mono-tube design and it has no effect on the damping rate ( not so with Sachs) . In most racing applications it is preferable to mount the cylinder up because this reduces your unsprung weight. This is a critical factor on super light suspensions or 200 MPH Land Cruisers. Glad they worked for ya!!!


:cheers:
Ames
Click to expand...


Isn't the unsprung weight/force the same whether it's valve orientation is either up or down? Or is that force determined by how far out the rod is?
My bilstein's are arriving on Monday and want to put them in right away. This is a good thread for me to find this out...
 
K2KK - Unsprung weight is the weight of the axle, tires, rims, brakes, etc. Anything that is under the springs, therefore un-sprung. Sprung weight being the weight sitting on the springs due to the chassis & body. What Kevin is saying is that by putting the cylinder up, and rod down your unsprung weight is less because the rod is considerred part of the unsprung weight as it moves w/ the axle and the cylinder is considerred sprung weight as it moves w/ the Chassis. Rod is lighter than the cylinder therefore somewhat less unsprung weigth that the alternative orientation.

He's poking fun that in our application this is obviously not critical at all due to the relatively high unsprung weigth associated w/ solid axles, large tires, etc and low different in weight of the rod and cylinder. Unless of course someone's building a 200mph FJ...

The force from the shock is relative to the speed the shock & suspension is moving, and more importantly if the movement is in compression or rebound, not the length it is extended. slow movement results in less force than fast movement, that's why we're able to compress the shock when installing, but try moving the rod fast and it ain't gonna happen.

My Bilsteins had a "pre-load" on them so they want to rest fully extended, I had to "work" them down and then "hold" to get them installed. Not too bad but not too easy either...

Good luck i think you'll be pleased regardless of how you mount them!
:cheers:
Ames
 
Many thanks for a good discussion about the shocks! I now know I will be able to mount them correctly once I get them...which should be shortly.

Cheers!!
 
Here is the straight dope from Mark at the Shox Shop. I just got mine in the mail and because of my lift needed longer shocks, so I asked him if the 5100 and the 5125 can be run upside down, Mark said that you can run them anyway you want, upside down, rightside up or sideways it doesn't matter. Some racers mount them upside down because of the slight difference in sprung vs. unsprung weight. The valving is the same he says. So, with that said I just might run them upside down so the road dirt and crap from water crossings and such won't gather on top of the cylinder. Mine are going on tomorrow...:clap:
 
researching this presently. thought Id add this however old

BILSTEIN Corporate - BILSTEIN

www.bilstein.com www.bilstein.com

"You always want to install our application specific B6 4600 and B8 5100 shocks so the Bilstein labeled on the shock body is reading in the correct orientation. If your shocks have been installed with the stickers on upside down then the shocks should be flipped the other way."
 
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