Rear suspension too soft on Mojave, squats

[KurtP]

I use ”bottom out” and “top out” interchangeably, so just be discerning which is which.



edit- here, this is from Fox that has a modeling of what we are talking about.

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[rogerWilco]

Assuming you want the bypass zone to function as designed; it prioritizes ride and articulation over load capacity. If your load varies wildly, you just add airbags and you have the best of both worlds.

Assuming a completely stock truck, you don't feel that adding airbags compromises any of what makes the Mojave suspension what it is?

Thanks for your insight,
Rick

 

[KurtP]

Assuming a completely stock truck, you don't feel that adding airbags compromises any of what makes the Mojave suspension what it is?

Thanks for your insight,
Rick

As long as you set the airbag pressure appropriately for the load- not one bit.

@b-roc whatchya think? airbags working fine?

 

[b-roc]

As long as you set the airbag pressure appropriately for the load- not one bit.

@b-roc whatchya think? airbags working fine?

I am happy so far.
I typically run with minimal load in the bed and 5 psi in the air bags ... no issues there.
I have had about 400 in the bed and 300 in the cab for a long highway run (don't remember the pressure setting ... likely 15 to 20 psi) ... no change in ride
Had a lightly loaded (800 ish load plus 15 ft enclosed trailer)trailer on my dad's property that a relocated for him that required the jeep use about half its articulation... but wasn't a long drive ... no issues (again, pressurized to level and was likely 10ish psi ... I would need to double check, but I believe that the limit is either 30 or 35 psi ... I haven't approached this yet)

I have not done the following which may matter for my setup (airbags y'd together)
1) max cargo all in the bed and requiring max articulation
2) any setup with a high center of gravity (e.g. rooftop tent)

... and I haven't put a ton of miles on them yet (3k or so)

I have only had one problem and it was my own fault ... I didn't put enough slack in the air line for a low pressure, max articulation scenario ... the line pulled out of the barbed connector on the air bag on the side with max drop ... I added some additional length and no issues since ... only other minor item, just like tires, is that the psi will vary slightly with ambient temp so depending on how particular you are then minor adjustments may be needed (I have only done this once ... 70 F to 15 F)

Good luck!

 

[KurtP]

I am happy so far.
I typically run with minimal load in the bed and 5 psi in the air bags ... no issues there.
I have had about 400 in the bed and 300 in the cab for a long highway run (don't remember the pressure setting ... likely 15 to 20 psi) ... no change in ride
Had a lightly loaded (800 ish load plus 15 ft enclosed trailer)trailer on my dad's property that a relocated for him that required the jeep use about half its articulation... but wasn't a long drive ... no issues (again, pressurized to level and was likely 15-20 psi ... I would need to double check, but I believe that the limit is either 30 or 35 psi ... I haven't approached this yet)

I have not done the following which may matter for my setup (airbags y'd together)
1) max cargo all in the bed and requiring max articulation
2) any setup with a high center of gravity (e.g. rooftop tent)

... and I haven't put a ton of miles on them yet (3k or so)

I have only had one problem and it was my own fault ... I didn't put enough slack in the air line for a low pressure, max articulation scenario ... the line pulled out of the barbed connector on the air bag on the side with max drop ... I added some additional length and no issues since ... only other minor item, just like tires, is that the psi will vary slightly with ambient temp so depending on how particular you are then minor adjustments may be needed (I have only done this once ... 70 F to 15 F)

Good luck!

Boom. Smashing bullshit internet myths. One data point at a time.

 

[MarcusB]

I use ”bottom out” and “top out” interchangeably, so just be discerning which is which.



edit- here, this is from Fox that has a modeling of what we are talking about.

Thank you, Kurt. That was very useful.

 

[MarcusB]

It was much harder than expected...

Pushing the airbags through gap in the coil spring didn't work. Maybe it was too cold outside and the airbag rubber plastic was too stiff, or I'm just weak.

To be able to lower the axle far enough to get the coil springs out, I had to disconnect the trackbar at the axle, the lower shock bolts, as well as the sway bar links. Even then I had to push them out with my feet. Reinstalling afterwards required a prybar underneath and pinched fingers.

Are the Mojave springs taller than stock? The airbags don't even touch until the weight is fully back on the axle. Maybe Airlift needs a thicker spacer puck for Mojaves? It's currently pumped up to 25 psi and it gained 1/2" in height (300 lbs approximately bed weight, with 1/2 height rack and Decked system in the bed). Is that correct?

Marcus

 

[KurtP]

It was much harder than expected...

Pushing the airbags through gap in the coil spring didn't work. Maybe it was too cold outside and the airbag rubber plastic was too stiff, or I'm just weak.

To be able to lower the axle far enough to get the coil springs out, I had to disconnect the trackbar at the axle, the lower shock bolts, as well as the sway bar links. Even then I had to push them out with my feet. Reinstalling afterwards required a prybar underneath and pinched fingers.

Are the Mojave springs taller than stock? The airbags don't even touch until the weight is fully back on the axle. Maybe Airlift needs a thicker spacer puck for Mojaves? It's currently pumped up to 25 psi and it gained 1/2" in height (300 lbs approximately bed weight, with 1/2 height rack and Decked system in the bed). Is that correct?

Marcus

How‘s it coming?

No, the springs to my knowledge are all the same free length, it’s just changes to spring rate that account for the height/ride difference front/rear. At least, on all the springs I’ve seen removed Side by side that has been the case.

Disconnecting the rear track bar shouldn’t have been necessary if the shocks were disconnected. I was able to get the stock springs out and new longer ones in, and added the rear spacer the other day without disconnecting the the track bar. I think you should be able to leverage the axle side down and get the spring in, although it is easier with a second person. It took me a few attempts on my own to get the spacer on the bottom and make sure the coil/coilbucket was oriented and in the correct spot up top. When the springs go back in, make sure the spring is oriented in the bucket/cup/isolator top piece correctly, and make sure the locator tab on the top fits into the chassis hole where it belongs.

They should not fill the spring at full droop, but should fill at static sag; so sounds like you’re where you need to be on that front.

In terms of height, my recommendation: you want to pump them up so you sit about 1/4”-1/8” below your unladen static sag height. Use this as a starting point, you dont want to over-inflate and over-stiffen out of the gate. If it’s too stiff/soft feeling, you can adjust from there to your liking.

 

[b-roc]

It was much harder than expected...

Pushing the airbags through gap in the coil spring didn't work. Maybe it was too cold outside and the airbag rubber plastic was too stiff, or I'm just weak.

To be able to lower the axle far enough to get the coil springs out, I had to disconnect the trackbar at the axle, the lower shock bolts, as well as the sway bar links. Even then I had to push them out with my feet. Reinstalling afterwards required a prybar underneath and pinched fingers.

Are the Mojave springs taller than stock? The airbags don't even touch until the weight is fully back on the axle. Maybe Airlift needs a thicker spacer puck for Mojaves? It's currently pumped up to 25 psi and it gained 1/2" in height (300 lbs approximately bed weight, with 1/2 height rack and Decked system in the bed). Is that correct?

Marcus

Sorry that you had a rough go ... I will check some measurements over the weekend if I don't get called in to work ... for others in the future ... I would suggest watching the install video linked earlier, but they definitely make some steps look easier than what I experienced... the most important steps that I did to get the airbags in through the coil gap is
1)remove black cap from barb connector
2) compress the bags as flat as possible with it still having a circular shape when viewed from above (i.e. pancake not racetrack) ... I did this in my house so that they were nice and warm ... the cold plastic could totally be what got you
3) replace black cap
4) raise jeep by its frame from the corner where you are working to maximize the gap in the spring (jack stand too, of course)
5) not all gaps are the same so look for the largest one
6) insert spacer and tape it, wedge it, something... to the upper portion of the spring
7) shove airbag in ... some nashing of teeth may happen here ... took more than 5 minutes but less than 10 for my first attempt at this and less than 5 for the second
8) route tubing
9) have pliers and tubing clamp handy
10) place something across the spring so that the airbag cannot expand vertically completely so that you have room to work for the next step (I used a large screwdriver)
11) remove black cap from airbag and attach tubing and tubing clamp to the barb connector
12) remove whatever was holding your airbag in place and also whatever was holding your spacer in place

 

[ColoradoBuckeye]

I use ”bottom out” and “top out” interchangeably, so just be discerning which is which.



edit- here, this is from Fox that has a modeling of what we are talking about.

Thanks for taking the time on this

 

[KurtP]

Thanks for taking the time on this

My pleasure, just trying to pass on what people and experience have taught me over the years. glad you found it helpful/informative.

 

[MarcusB]

Update: At 25 psi, the Mojave gained significant height in the back but the suspension was too stiff. I decreased to 15 psi and that seems to be great !

 

[KurtP]

Update: At 25 psi, the Mojave gained significant height in the back but the suspension was too stiff. I decreased to 15 psi and that seems to be great !

Great!

 

[Mtpisgah]

Sorry that you had a rough go ... I will check some measurements over the weekend if I don't get called in to work ... for others in the future ... I would suggest watching the install video linked earlier, but they definitely make some steps look easier than what I experienced... the most important steps that I did to get the airbags in through the coil gap is
1)remove black cap from barb connector
2) compress the bags as flat as possible with it still having a circular shape when viewed from above (i.e. pancake not racetrack) ... I did this in my house so that they were nice and warm ... the cold plastic could totally be what got you
3) replace black cap
4) raise jeep by its frame from the corner where you are working to maximize the gap in the spring (jack stand too, of course)
5) not all gaps are the same so look for the largest one
6) insert spacer and tape it, wedge it, something... to the upper portion of the spring
7) shove airbag in ... some nashing of teeth may happen here ... took more than 5 minutes but less than 10 for my first attempt at this and less than 5 for the second
8) route tubing
9) have pliers and tubing clamp handy
10) place something across the spring so that the airbag cannot expand vertically completely so that you have room to work for the next step (I used a large screwdriver)
11) remove black cap from airbag and attach tubing and tubing clamp to the barb connector
12) remove whatever was holding your airbag in place and also whatever was holding your spacer in place

You make it sound so easy. I gave up and paid the shop $120 to do it. The truck rode better but still too much sag in the rear and the front is still bottoming due to the winch and bumper. So, it goes tomorrow to get a lift With heavier springs.

 

[PabstBleuRibbon]

Great thread with lots of good info, thanks all. I have a question:

Future planning for my Mojave include winch/OEM steel bumpers/RSI cap, moderate payload (3-400 lbs plus 2 passengers), and towing a small overland trailer, ~3000lb loaded, ~210-250lb tongue weight.

I'm thinking the new Fabtech 2" lift kit would be good for this? It sounds like a lot for just airbags in the rear is all. Also when not trailering I'll often be hanging a dirtbike hauler off the rear. Truck is already riding on 315/70 ko2s c-rated, and the ride quality is excellent...I'd hate to lose that as a daily driver.

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