One of these things is just like the other?

I am the go-to guy when people need help with anything from stuck cars to home repair to lock outs. These requests happen at all hours and usually horrible weather. I enjoy this role and like to get anywhere at any time to do anything which requires a capable truck. I don't do heavy offroading or crawling but it's less about seeking intense trails and more about mitigating the impact of intense conditions.

I'm after a 1-1.5" lift for increased articulation so I can get the most of my 2017 OR but also enjoy the look of a mild lift. Please save the jokes about locking diffs and hardware stores, having it doesn't require using it every weekend. The best method for this use and lift amount seems to be 5100s all around and AAL in rear. I don't need more and don't want to mess with additional parts like UCAs, transfer case drops, and all that. I also plan to upgrade to 135/85-16s soon but have no intention of bigger tires.

Tons of research has led me to the 5100+AAL method but I'm confused on some finer points of this method compared to others.

This excellent post breaks down spacer kits into strut spacers vs in-coil spacers. How is an in-coil spacer any different than adjusting the clip on the 5100s? I understand it's not quite that simple because of the change to strut travel so let me rephrase: IN PRINCIPLE how is a 5100 with the clip adjusted for lift any different than another strut with travel equal to the 5100 and an in-coil spacer?

This video talks about control arms hitting struts, ball joints hitting struts, added stress to CV boots, and added stress to steering components. This is somewhat different since it's a strut spacer lift but the problems he lists seem like they would apply to the 5100 method. This is also roughly the same amount of lift I'm after so it's not like he's talking about problems with a 3" spacer kit, it's pretty mild.

Why is the 5100 method exempt from the same downsides the in-coil spacers have (according to the links above) like reduced up travel and all the added stress? Does the difference come down to new struts made for the lift vs stock struts?


HERE IS THE MOST RELEVANT BLOCK OF TEXT FROM THE LINK:
In-coil spacer kits do not increase the length of the coil assembly to accomplish lift. Instead, they reduce the amount the factory coil can compress by “taking up space” in the coil pack. This is commonly (and incorrectly) referred to as spring “preload.” In-coil spacer kits are well-liked because:

• Provided you have access to a quality spring compressor (or a local shop that has one), in-coil spacer kits are very easy to install and do not require any prying like above-coil kits
• They are usually very inexpensive

The downsides to this type of kit are reduced up-travel and, arguably, reduced ride quality. Since the spring isn’t technically being “loaded” (it’s just losing some compression height), ride quality isn’t effected by a suddenly stiffer spring. While it is true that reducing the amount of compression distance slightly changes the spring rate, the difference in ride is likely very small on most vehicles. Many people who have installed in-coil spacer kits have not noticed a decrease in ride quality.
However, the reduced up-travel is an issue with in-coil spacer kits. By reducing the up-travel, the truck is more likely to hit the bump-stops during hard use. Obviously, hitting the bump stops results in a severe jolt and – if done excessively – can have multiple negative ramifications.

Combo kits use both an in-coil and above coil spacer to accomplish lift. By using both types of lift, these kits minimize the downsides of both designs while also gaining the benefits of both. In truth, most in-coil spacer kits – as well as adjustable “leveling shocks” like the Rancho quickLIFT or Bilstein 5100 – fit into the combo kit category.
Shock-based leveling kits offer quite a bit of value. They cost about the same amount as a quality above-coil or in-coil spacer, yet they also include new shocks. The main limitation of these kits is that they max out at about 2.5″ of lift.
Remember: Spacer lifts are the most popular type of front-end lift / leveling kit. Provided your truck doesn’t see much off-road use, it’s unlikely that any of the issues associated with spacer lift kits will ever cause you a problem.

 

Adjusting the clip on the Bilstein 5100 coilover is exactly like a in-coil spacer. However the Bilstein has options to either add or remove preload on the spring. In-coil preload spacer is just one option.

Not a strut, but yes a coilover spacer that goes on top of the coilover to provide a lift is very different than an in-coil spacer that is adding preload. Adding a spacer lift will make the overall extended length of the shock much longer than you would find on an extended travel coilover from a company like Fox or King. These big name companies have these extended lengths for a reason and these spacers push the limitations of the front suspension, steering and drivetrain.

Maybe a misunderstanding of the preload spacer is the issue for others trying to compare to a Bilstein 5100 coilover?
Reduced up travel could be caused from coil bind, otherwise nothing would be limiting the shock from compressing to the max. Too much preload can definitely make the spring go into block height before the shock is fully compressed. This applies to ANY coilover setup. It's common for someone to add too much preload to get their desired height, which should be fixed with a heavier rate spring.

In coil spacers do not increase the length of the coil assembly, or shorten it. It also does not change the shock travel. You do not lose shock travel by adding preload to the spring. Adding preload also does not change the spring rate, so it will not make the coilover ride stiffer bc of a stiffer spring. If there is a ride quality issue after adding preload (or in-coil spacer) it likely is due to the shock being too tall at ride height and not offering sufficient down travel for common driving. Frequently topping out the shock can make the vehicle feel like it's riding rough/stiff. This is why we have recommended preload amounts on the coilovers we sell and recommended shock lengths at ride height. These recommendations are to ensure ride quality is the best possible.



Made a quick diagram to help visualize some of the things I mentioned above. This gives you a good idea on the differences btw an in-coil preload spacer vs a spacer that goes on top of the coilover. This diagram is also referring to the shocks off the vehicle and fully extended.

 

That diagram is super helpful and I appreciate the qualified reply. Thank you!