Mack207

The problem with adding 5100's to a spacer is that the 5100's are longer than stock shocks. So when you add a spacer, the shocks become even longer than stock, and the suspension has the ability to extend further down. You could get new UCA's that allow for more droop, but then you may overextend the tie rods and cv axels. If your running any sort of front diff drop bracket, it will help with the geometry, but in the end, 5100's with a spacer will still provide more droop than what the drop bracket is designed for. My suggestion is to run 5100's alone, or with a smaller spacer than whatever came with any spacer kit you bought. Trucks with aluminum front suspension would be hard pressed to get even a 1" spacer in between the 5100 and the coil perch or lower CA before the uca contacts the droop stop on the frame (I tried it). I'm going to try 5100's on the second setting (.75" lift) and either a .50" or .75" spacer below the shock. I think any more than that the cv's will be very unhappy when the suspension is fully extended. And yes, this will only be around 1.5" of lift, but I will have more droop travel over stock shocks and a spacer that gives a similar amount of lift. Function over form. I may go to a 1" spacer and new UCA's if this setup works out and the driveline geometry is too out of whack.

Because the Bilsteins are longer than the stock shocks, you would most likely get control arm to droop stop contact. Do you have the aluminum or steel suspension?

There's no reason they wouldn't work, other than dampening. I've used 5100's on other "max tow" equipped trucks (Titan) and it was a vast improvement over stock.

How far away is the upper control arm from the frame bump stop fully extended? That's good to hear that you can fit a spacer in with the steel suspension. I don't know that you can with the aluminum.

The dampening, quality, and warranty are the reasons I have gone with 5100's on all of my vehicles (Grand Cherokee, Titan, AEV Jeep JK, GMC Sierra). The stock shocks on all of them were too bouncy over any type of rough terrain. I've also had to warranty a shock through Bilstein and they sent me out a new one without any questions. The OEM Rancho's on the 1500's have way too much bounce for my liking. Low speed turns are like driving in a boat when compared to 5100's. The argument for spacers is that they are simple, and mostly don't change what you currently have. They're also the only option for the magnetic ride if you have that. For $200, $350 installed with an alignment (or $250 if you do the install yourself, then get an alignment) 5100's are a no-brainier for me. And no, I don't work for Bilstein.

I said max height just as an example. I've ran 1.5", 2", and 2.5" on the same vehicle. The change in ride is small enough that most people won't say anything about it or really notice it, but there is a change. It also depends on what type of spacer you use. A spacer that mounts to the lca / bottom of the shock won't affect the ride as much as a spacer that sits on top of the shock. I think this is the reason most GMC / Chevy owners don't notice a change in ride as much. Most other vehicles only have a top of the shock spacer. With 5100's being longer than stock, yes the down travel at a higher setting my be equal to that of stock. But when comparing a 5100 at the top setting to a 5100 at the bottom setting, the one at the top setting will have less down travel with the weight of the vehicle on it.

But as you go higher on the Bilsteins, you still lose down travel. When compared to the stock shocks, the travel may be the same on the Bilsteins on the 2nd / 3rd setting. You would have to compare the exposed shaft length on the 5100's and stock shocks with the weight of the vehicle on it to determine if the down travel was the same at a certain setting. Then subtract that from the total shaft length. Spacer kits limit down travel by overextending the OEM components.

The ride does change with a spacer though. As I said before, the "same as stock" statement is simply not true. I ran stock shocks with max height spacers and the ride was definitely more firm. It's also why I said that I believe preload does contribute to the increase ride firmness. The ride is not the same when comparing a 2" spacer to 2" of lift with Bilsteins. Bilsteins dampening is also firmer than stock, and as you go up, the firmness is amplified by the increased angles. You're correct that the truck weight does not change. The spring compresses a certain amount under this weight. Raising the bottom spring perch compresses the spring on the shock by a certain amount as well, but the shock is at full extension. Because the spring only compress a certain amount with the weight of the truck on it, and you have already compressed the spring some with the shock fully extended, the truck will sit higher. You lose down travel here because the shock is more extended at normal ride height.

You won't be able to get a 2.5" spacer in with 5100's because they are longer than stock. You'd have to get new upper control arms. Top setting with .5" spacer may work. You could get the Bilstein 4600's, which I don't think are longer than stock, and run a 2.5" spacer. The dampening on any Bilstein is far better than the stock shocks.

The only thing the snap ring positions change is preload. The shock doesn't get longer. The increased preload keeps the shock from compressing more under the vehicles weight, creating lift, at the expense of down travel. The increased ride firmness is from the increased angles the suspension is operating at. I also believe increasing the preload increases the ride firmness, but others don't. The Rancho's ride bad because of their bouncy-ness. People complain of the 5100's riding bad because of the stiffness. Two different ends of the spectrum.

'14 All Terrain. Bilstein 5100's at 2nd (+.75" lift) setting. Can't wait to get rid of these factory tires for something more aggressive. At the wife's family farm in Tennessee.

The 5100's are longer than stock shocks, so any spacer added makes them an even longer assembly, which can over-extend the uca ball joint and cv joints. If you have the aluminum suspension, you'd be lucky to get a 1/2" spacer in without the uca contacting the bump-stop. It was my original plan to run 5100's on the 2nd setting with a 1" bottom spacer, but after I saw how much longer the 5100's were, I knew it wouldn't work without contact.

$650 installed is very high for 2 hours of work. I would order them myself then take them to a shop to install. Install should be around $100, then another $50 for front alignment. All you really need to install these is a table mounted vice and rented strut compressors. I just switched for the Rancho's to 5100's on the 2nd (+0.75" lift) setting, and it's a huge difference. No more bouncing making a low-speed turn, and the truck feels much more stable on the highway. I've run 5100's on my past three vehicles, and they're always worth the price. I install everything myself though.

Does anyone have a pic of the top mount of the 5100's when they're on the vehicle, or can someone go take one? I torqued the top nut down to Bilsteins measly 25 ft/lbs, and that doesn't seem right. The top spacer right under the nut can spin when the weight of the vehicle is on it. The last set of these I did, on a Titan, had a definite stopping point.

I just installed a set on the second setting on my truck today. I'm still running the factory goodyears and I didn't want them to look out of place. They gave .75" of lift as advertised. When I get new tires, most likely 275/60R20 or 275/65R20 I'll go up to the third setting. Ride is much better; I'm not bouncing all over the place now. Lift is noticeable to me as well, which is the most important thing lol.