Bilstein 5100 adj shocks (front and rear)

boone9 · February 10, 2015

Well I got them installed today. And to be honest... it was a $650 dollar mistake on my part. I should have never messed with what I had. The new shocks may handle the bad bumps maybe a little better... but defiantly not worth the cost. Actually seems like everything else may be a little harsher, but the bad bumps..

A side note.. they did have keep my 2in level installed. Something about the top bolts were cut when the level was installed a year ago. Anyway... instead of removing the level, and extending the shocks out to max 1.8 in.... they left the level in place and keep the shocks at the "factory" stock adjustment..... no extension.

Not sure which way would give the best ride.. as I have heard extending the shocks to max 1.8in can also make for a a harsh ride.

Anyway.. the whole deal was a waste of 4+ hours and $650 bucks.. in my opinion....

Question answered. Thanks for the bad news, and good news. Good news being im not going to waste my money on the front bilstein and just keep my set up with ranchos in the front with 2.5 inch rough country and 5100 rear bilsteins. Bad news being bilstein cant make the ride better, using this set up. Still to be determined if the full extension 5100's will be a better ride.

Ten7 · February 10, 2015

Well maybe I wasn't looking at it wrong. This is from page 4 of Bilstein's PDF

http://www.bilsteinus.com/fileadmin/user_upload/user_upload_us/pdfs/Bil_LevShks_WebArticle.pdf

Increased Rebound Control

The lift on the 5100 Series leveling shocks is achieved by increasing the preload on the factory coil. By adding more preload, the shock is designed with more rebound damping as compared to the O.E. or standard aftermarket replacement shock.

So it sounds like they do increase the preload and then control that by adjusting the rebound, and increase the stroke length to restore travel.

If the Rancho QuickLift are well built then it seems like they would be a better option, assuming you wanted approx 2" of lift, because you can adjust them for your use and they are designed for the full height. It seems the Bilseins would have to get worse as you move them from whatever the optimal setting is, which is probably somewhere in the middle.

Sorry if this is a thread jack...

southern_sierra · February 10, 2015

Question answered. Thanks for the bad news, and good news. Good news being im not going to waste my money on the front bilstein and just keep my set up with ranchos in the front with 2.5 inch rough country and 5100 rear bilsteins. Bad news being bilstein cant make the ride better, using this set up. Still to be determined if the full extension 5100's will be a better ride.

Think you answered my question to about ride. I don't have a lift and have the stock ranchos.

To me they ride good on the highway but to stiff in town you can feel every little bump. I wish I had a set of oem shocks that come on the regular 4x4 (non z71). Bet they would ride good.

mtbsam · February 10, 2015

It can't increase preload on the coil unless it adds more sprung weight to the front, that is just poor wording. The spring rate of a coil spring doesn't change. It does change your control arm angles and that makes a difference in the ride quality, however.

I don't have my leveling fronts installed yet so I can't speak on how the ride changes, but it's going to be interesting to see. I think the part I like the most is the extra inches of shock stroke. Time will tell as to whether I like the ride or not.

mtbsam · February 10, 2015

Actually, I was slightly wrong in my prior statement, but streepening control arm angles actually DECREASES preload on the spring.

Edited February 10, 2015 by mtbsam

thetruck454 · February 10, 2015

Preload is defined as the distance the spring is compressed vs its relaxed length. The bilstein 5100 does increase preload ,it's no different than the threaded collar on lots of motorsports shocks. Spring rate is a characteristic of the spring and will not change.

Edited February 10, 2015 by thetruck454

310racing · February 10, 2015

Preload is defined as the distance the spring is compressed vs its relaxed length. The bilstein 5100 does increase preload ,it's no different than the threaded collar on lots of motorsports shocks. Spring rate is a characteristic of the spring and will not change.

You stiffen due to limiting the available travel due to spring tension, as you tighten the spring, coils start on the top and bottom of the spring lay on each other, forcing the center of the spring to due the work, same tension, just less compliance.?.

Edited February 10, 2015 by 310racing

Jackseric · February 10, 2015

Chad2815 · February 10, 2015

When I talked to Bilstein I was trying to decide between the 4600 and the 5100, they told me that the 5100 was designed for the level and that if you left them at the "factory" setting in the front that the ride would be harsh. I set mine at the third setting (1.28) because for whatever reason my truck had very little factory rake.

Coach Hill · February 10, 2015

I set mine at the third setting as well and I think it rides and handles better than stock.

mtbsam · February 10, 2015

Ok, I need to rephrase my statement....yes the preload on the unloaded shock has increased. However, since the sprung weight hasn't changed, it will still settle to the same amount of compression because spring rate hasn't changed either. This is what lifts the front and (I believe) why Bilstein adds the extra inch of shock stroke to accommodate the further negative travel.

The potential harsher ride comes in where the angles are steeper. The closer to vertical the control arms get, the more force and energy is transferred into the chassis instead of into the shock.

GMC-AT · February 10, 2015

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Edited February 10, 2015 by GMC-AT

Chad2815 · February 10, 2015

I agree, I think the third setting is the way to go if you dont do blocks in the rear. Front to back I am about 1/2 inch difference. My dealer checked my aligment after the install and said I didnt need to re-align, should I go ahead and do it anyways? I figured they knew what they were talking about. Front and back install was 300

Skeeter McSkeet · February 10, 2015

I agree, I think the third setting is the way to go if you dont do blocks in the rear. Front to back I am about 1/2 inch difference. My dealer checked my aligment after the install and said I didnt need to re-align, should I go ahead and do it anyways? I figured they knew what they were talking about. Front and back install was 300

I agree, I think the third setting is the way to go if you dont do blocks in the rear. Front to back I am about 1/2 inch difference. My dealer checked my aligment after the install and said I didnt need to re-align, should I go ahead and do it anyways? I figured they knew what they were talking about. Front and back install was 300

Are you ~1/2" nose high or low?

-Skeet