Bilstein 5100 Shock Length and Rates

[Jeff Conner]

Hey guys,

I've done some research on what size Bilstein 5100 shocks I should put on my truck. It seems that I stay with the stock length up front, but then for the rear I can get the 3 inch lift version because I have the poor man's lift. (Calmini shackles, and their HD torsion bars) I'd like to only have to buy new front shocks if I get the full 3 inch lift in the future!

My questions are these: Will I notice any difference in on road handling with the longer rear shock? My biggest concern was that it could bottom out easier since the body is longer and would be more compressed than it would be if it was on a true 3 inch lift application.

And then what are you guys using for valving? I'm currently getting ready to order the Shrockworks front bumper, so I know I should probably go with at least the 10% stiffer model, but would 20% be any better? I wouldn't be getting a winch for at least a little while. The wallet will need some time to recover!

Thanks!

[ChefTyler]

You won't notice a difference in ride if you stay with stock valving.
I could be wrong, but the front shocks won't need to be swapped with the 3" SL, unless you're going with a long travel kit, because you aren't changing the amount of travel of the front suspension you're just decreasing droop and increasing stuffage by increasing the stock ride height. Make any sense?

I would definitely go with the 20% stiffer at all four corners, helps improve ride quality dramatically.
:D

[GarrettE]

What is the best place to get the 20% stiffer Bils at?

Since I am doing a BL and a PML I was looking at getting new shocks as well (I think my stockers are shot at 25k right now), and was just looking at getting the ones from AC that are for a 3" SL.

What would be my best bet for right now as far as getting new shocks? Longer than stock and 20% stiffer too?

[Lance T]

I ordered two sets from SLR...once from Spencer and the other time from Josh. They came quickly and were priced competitively but one set was 20% stiiffer 5100's and the other set was 5125's.

On the back you will need a 10" stroke shock. On the front when you change out the arms to AC arms or something you can space out the front shock with $10 of poly from any 4x4 store. The shocks from SLR are spaced using a metal spacer but you can make your own like Mike did. The shorter length stock shocks will limit your wheel travel and eventually destroy the shock.

I would go with the 5125's...two schools of thought on mounting.

1. Body on top - This will be your preferred method. Monotube shocks (Bilstein, King, Fox, Sway-A-Way, Walker Evans, Radflo) can be run either way but this way will protect the thinner walled shock from dammage. NEVER, run a twintube (Calmini, Rancho, Monroe, etc.) shock this way...they will leak and fail.

2. Body down - There is no good reason to run them this way...supposedly you could protect the shaft but the shaft is a much smaller, more durable piece than the shock body. The only good reason is theat you have a post mount shock and have no choice. These post types are usually well enough protected (i.e. IFS) that you don't have to worry.

[JayRyan]

Lance said it. I have the same setup he does- PML only, 20% stiffer all 'round- extra stroke in the rear. I ordered from Josh at SLR as well with :thumbsup: for service and ship time. Ride quality rocks even with a disco'd sway.

[Jeff Conner]

SLR no longer lists a 5125 shock. They only list the 5100, 7100, and 9100 series.

I checked 4x4parts.com and they show a 5150 shock. I'm confused about the two options though. In the 10 inch model there are two valving options. 170/60 and 255/70. What do those numbers mean?

And to clarify things a bit, the front shocks stay the stock length unless I upgrade to bigger UCA's. But in the rear I can/should use longer shocks. And using stock length would be bad anyways because the wheel travels more than they're capable of. Does that sound right?

So then are you guys mixing the higher performance shocks in the rear and the stiff 5100's in the front?

From what it looks like then, it would be good to get the 10 inch 5150's for the rear, and then 20% stiffer 5100's (stock length) for the front.

Thanks again for the all the help!

[JayRyan]

IIRC, the 5125 is the SLR modified 5100. It's modified for the extra length in the rear. The have the lifted/altered suspension choices for the rear at the bottom of the page. For the life of me, I can't remember what I ordered. You might want to just call and talk to Josh about what your setup is (or going to be) and what you'll want to order as far as altered suspension.

I don't know what the valving numbers mean. I'd love to know though. I knew I needed it a bit longer in the rear running no sway and I knew I wanted them stiffer. But not knowing anybody at the time, I just called and asked.

[Lance T]

They are you rebound and compression numbers in Newtons...not fig. With the single shock application use the 255/70. This will be stiffer than the intial stock application.

SLR never listed the 5125's, you can ask for them when you call. The 5150's have a reservoir...do it if you want but typically normal crawling around doesn't rquire a reservoir.

[Eric P]

Jeff;
This is the model number for the 20% stiffer rear shocks with a 3 inch lift. I ordered these from SLR.

They are ~ 1/4" short at full droop.
http://www.pbase.com/sms/image/58089977.jpg