Max rear wheel travel

[piroman683]

Hey Gang, has anyone been able to get more than 16in of wheel travel on the rear without going full tilt on a professional trailing arm set up? I thought I was going to achieve 18 but it looks like I miss measured and am stuck at 16. I cannot compress anymore even though I have shock length left since the springs would be in total bind and the fox bump stops don't tuck up high enough.

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[CrazyCooter]

So now you need longer shocks or move you axle brkts up a bit? Do you have the spring preload to allow more droop with your current setup?

 

[piroman683]

My shocks have 2 more inches of compression travel I can use. I have rock krawler 4.5 in springs and at full drop I’m at my max extension. At full compression i have 2 inches of shock shaft left. Problem is im at max compression of the spring. Shorter springs would allow more compression but I’d lose max extension

 

[piroman683]

For reference I’m not running coil springs and don’t intend to unless I go full blown like Darren Parsons

 

[CrazyCooter]

Sounds like you are maxed out without doing some custom work.

Without doing some crazy trailing arm coil over setup, a longer coil with a slightly lower spring rate and fab a lower profile lower coil bucket? Could squeeze out another 1-2" up travel? Maybe even ditch the rubber isolators for another .75-1.5"?

Sounds like you have enough tire/fender clearance to accommodate a bit more uptravel?

Are you pounding this truck so hard that you absolutely need this travel? Seems like I've seen posts from you about jumping?

 

[Glamisfan]

It sounds like you need to try single rate springs. As I was doing my research for maximum travel and a low center of gravity, I found that the double and triple rate springs have more windings so they are taller when fully compressed. Single rate springs usually are able to compress a couple inches more than triple rate.

Do you have aftermarket suspension links? Because the rubber bushings in the stock ones really limit the total amount of travel you can get.

 

[piroman683]

I definitely pound the shit out of my JT. I looked to see if there was any way to shift the upper coil plate up but it’s already at its highest limit. I’d love a single rate spring which is what I have in the front (Clayton off roads 3.5in coil at 188 lbs/in), but gave not had luck on the rears. With the multi-rate springs I end up with a softer average spring rating which as you mentioned complicates things. I emailed Synergy as they have a 5 and 6in lift spring due to come out soon, and based on the max compression of their others it might work for me, but I do worry it will be too soft. I think my real next steps are to check with some suppliers on getting a custom coil.
All my control arms are upgraded so no issues with rubber bushing binding

 

[CrazyCooter]

I definitely pound the shit out of my JT. I looked to see if there was any way to shift the upper coil plate up but it’s already at its highest limit. I’d love a single rate spring which is what I have in the front (Clayton off roads 3.5in coil at 188 lbs/in), but gave not had luck on the rears. With the multi-rate springs I end up with a softer average spring rating which as you mentioned complicates things. I emailed Synergy as they have a 5 and 6in lift spring due to come out soon, and based on the max compression of their others it might work for me, but I do worry it will be too soft. I think my real next steps are to check with some suppliers on getting a custom coil.
All my control arms are upgraded so no issues with rubber bushing binding

Do you haul a load in the bed at all? If not, I would think you could use a similar rate to the front with axle weights pretty similar on a gas JT?

Maybe some front springs flipped upside down so the pigtail is at the bottom? Looks like free length rears are 1" longer so you would need a 5-6" front to land at 4-5" rear lift?

I'll be swapping my rears springs tomorrow, so may have to test fit a front spring back there........hmmm. I also have a pair of rear JK coils I could test too. Maybe a set of Synergy 7" rear JK coils?

Do you like the Clayton front springs? I just swapped a set into my diesel Friday and like so far, but I would think a gas rig would like a softer spring?

 

[piroman683]

I love the Clayton front springs. My front end would start to stuff itself on whoops because the previous springs were around 120lbs rating, the 188’s make it so much better.
I’ll definitely need to look into possibly using fronts flipped upside down, I didn’t think about that.
I found a nice spring weight calculator that I used to better help me understand what spring rates work best with my weight and travel. It suggested 190 in the front and I think 225 in the rear. I need to find the link and I’ll post it here. My truck is light too as I only have about 150 extra lbs from my rock sliders. I’m going to weigh it before I send my shocks for a revalve so I’ll post that as well

 

[CrazyCooter]

Looks like any of the TJ, JK, or JL springs would work upside down except the TJ coil I have didn't have a super flat large end, so would need an isolator or grind it flat. Down side is trying to find a rate over 200. The Rubicon Express 5.5 coil I have comes out at about 160lb 22.5" free length.

You might be looking for a custom coil?

 

[piroman683]

Been a while since I posted on this thread, so here's a quick update. I did go with custom spings, a bit expensive, but I'm in development mode and can stomach it for the moment ($450/pair).

I achieved 17.5in of wheel travel, but now the rockjock swaybar arms are hitting the fenderwell. I saw the [Banned Site] video on their solution and am in the process of testing a similar solution. I'll have results by Labor Day weekend. For ref. my free length is 25.75, and compresses to 7.75. This is a lot, but it is also within the fatigue life of the spring with some great margin which is awesome. I need to do another day of tuning because I still have a little too much rebound, but I am definitely moving a lot faster on the whoops! I've tested a 160lbs spring that ended up being a bit too short (25in free length, 7in compressed), so the next test will be the slightly longer one at 150 lbs. Stay tuned!

 

[CrazyCooter]

What do you have for rear link/geometry combo? I found the stock control arm geometry really alters pinion angle through the range of travel and could benefit from some help. I have been using the Tera bracket. This rotation also has to be playing with the shock's effect since the bracket is mounted forward of the tube.

 

[piroman683]

i installed the rock krawler pro-x upgrade kit and have Clayton off road lowers. This eliminates the track bar and allows for full range of wheel travel. The pinion only moves about 1-2 deg during cycling. This is definitely a must for more wheel travel.

 

[piroman683]

Some of the big challenges was getting a spring that compresses enough to actually utalize the whole shock travel. I also cut my exhaust forward of the rear axle as it was getting smashed with the amount of uptravel I have over stock.

 

[CrazyCooter]

Some of the big challenges was getting a spring that compresses enough to actually utalize the whole shock travel. I also cut my exhaust forward of the rear axle as it was getting smashed with the amount of uptravel I have over stock.

You are definitly on the extreme side of this kind of stock platform suspension build!

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