More Up Travel or Down Travel?

Just purchased 2015 Crew Cab 4x4. Previous owner has a two inch block lift and airbags. Looks like he has the stock black housing shocks on there? Looking for some insight here.

Looking to replace rear shocks as they look pretty warm. Decided on Bilstein 5100s, but trying to decide between the 2” lift model or the ‘up to 4” lift’ model.

Ride measurement (middle of mounting hole to top mounting bracket) with no weight in the back and 10 psi in the bags:

Shock Ride Length at Rest

• Left: 24”
• Right: 23.5”

Looking at the measurement on Bilstein website, and calculating remaining up and down travel against my ride height length…

With 2” lift Bilstein:

• Right: 6.16” of Up Travel, 3.31” of down travel remaining
• Left: 6.6” of uptravel, 2.81” of down travel

With up to 4” lift bilsteins:

• Right: 3.85” of uptravel, 5.62” of down travel remaining
• Left: 4.35” of uptravel, 5.12” down travel remaining

My question is, is it better to have more up travel or more down travel? 2.81” down travel remaining seems like not enough, that a pothole could fully extend it.


Thanks!!!

 

Wow, looks like some home made air bag mounts, with a partially welded upper mount?

Up travel is dictated by the bump stop, well it should be anyway. Assuming the bump stops are setup properly, you will also need to factor in a longer shock having a longer compressed length, which would need a longer bump stop spacer. Also, leaf springs may or may not cycle the full travel, so longer is not always better.

Our rule of thumb here is getting at least 3" of down travel from ride height.

 

@AccuTune Offroad

Thanks for the thoughts! So any recommendation as to an easy way to test the integrated bump stop length with bags? Maybe let all the air out, then jack up one side? Or just let all air out of bag and see from axle to bed, the distance with the assumption that it’s sitting on the integrated bump stop.

Regarding the airbag install, yea I noticed the same. They look like they’ve been on there for years, and have held up. I will replace them with a proper install method at some point in the near future.

 

There is really a lot going on there. For vehicles without an air bag replacing the bump stop, you would just compare lengths of the shock to the bump clearance you have. You could just unbolt the lower side of the shock, measure those and compare to whats available.

 

Ended up getting the up to 4" lift Bilsteins. I did some googling and most say 4" of up and down travel is good, 3.81" of uptravel I think will be fine given I have airbags that will limit compression.

When I take off the existing ones, I will measure them for extension and compression just for reference, as going by the measurements of the ones on there assumes that whoever put them on was correct in their determination.

 

Installed them.

The ones on there were KYB. I didn’t end up measuring them, but fully compressed seemed about 16”, so a lot of up travel there given the normal ride height length was 23”. But had about 2” of down travel. My guess is whoever put them on, just threw them on without really paying attention. Will post here if anything doesn’t turn out good

Found some that fit Tundra on Summit Racing and looks like my suspicions might be right:


Summit Racing Part Number:
KYB-349054
UPC:
781552590293
Extended Length (in.):
24.41
Collapsed Length (in.):
15.19