Lift Install
Lifting a cab/chassis is not for someone who wants turn key, easy button. It is not that it is difficult to do, so much that there is a lack of support and knowledge.
The front of the truck is essentially the same as a traditional 3500, so all the same parts fit. The rear has shorter shocks, different springs, different u-bolts, different clearances, etc. The only answer out there I was able to find was if you paired up with an AEV dealer who knew their secret sauce. Mario at AT Overland does, as per evidence of his Aterra XL truck camper at Expo West the past two years. I reach out, and he told me he could get the parts. I sought quotes, etc. After a bit of back and forth, it seems that the small nature of my project fell through the cracks. Want to build out a full truck with him, you're probably in luck. It's probably a matter of so much demand, and prioritization of clients. AEV themselves were no help at all, despite multiple attempts on my part.
What's the secret sauce in their lift...from what I can gather...is a spacer, longer u-bolts, rear airbags, and moving the stock rear shock lower mounting points up 1" by cutting them off and re-welding them back on. The airbags are optional, and likely were added on for increased weight over the factory leaf's capability.
What it did do for us is forced us to seek alternatives, and come up with our own package.
Not being super thrilled with the lack of response, we moved away from AEV for a lift. We did purchase 5 wheels from them, as we like the way the Saltas are reminiscent of EVO Corsa style wheels on some of the Dakar race trucks. Plan B would have been something like a Method with the bead grip feature.
We reached out to a number of suppliers such as CJC, Thuren, Carly, and a few more as part of the process. In the end we went with nearly all Thuren up front by using the following:
- Thuren HD trackbar
- Thuren 2.25" lift coils
- Their Bilstein front shocks to use in a temporary fashion
- Fox ATS steering damper
- Sumo Springs bump stops
Out back we used their Bogie rear bump stops, and made our own 2" spacers out of 3/16" wall steel square tube.
Other items sourced include:
- Fox 2.5" bypass shocks with adjustable high and low speed compression both front and rear
- Fronts were an easy order, as we only had to provide weights and characteristics of the tune we wanted - note that these are still on backorder, so we're using the Bilsteins for now
- Rears were adapted from a GMC product, with custom tuning and minimal modification of the upper eyelets
- 2" spring spacers for a 4500/5500 by PMF that we had to modify
- Longer u-bolts for a GMC product
Still in the works...in shipment as we're typing... are full rear leafs and appropriate u-bolts specific to measured/projected weights (the spacers were always a temporary fix)
Installation
We started with the rear as it was less turn-key, and we knew there would be issues. Lifting the rear with a 20-ton air over hydraulic bottle jack was easy, but we didn't get it right the first time. Everything had to come up more, so a lot of 2x4 sections were cut to make platforms to achieve the necessary height.
2x 3 ton jack stands in place, with a 20 ton bottle jack as backup. Both front wheels chocked.
A standard floor jack to manipulate/support the axle at various times, and some ratchet straps to move the axle fore/aft for repositioning when putting things back together.
It took time to figure out exactly how to fit the rear shocks since the piggybacks had to clear the frame notches, and exhaust hardware. Upper sleeves were drilled out to fit the factory shock bolts. The PMF spacers required minimal modification, essentially removing some material for the center pin as this setup has a center pin and two bolts for a total of three pieces to align vs. your more standard one centered piece. No issues there other than time.
In all the rear took half the day. We could knock it out in about 3 hours or less on a subsequent attempt. Perhaps less with a proper lift.
Rear wheels mounted, now ready to start the front lift.
The front lift took longer to do, but mostly due to other distractions we had to deal with unrelated to the truck. In essence you lift everything up, block brace, support, etc. to make everything stable and safe.
In the end it is longer shocks, longer springs, swapping out the track bar, and swapping out the steering dampener. The thing that took the longest, believe it or not, were putting the bump stops in. What should have been as easy as pressing them in place...was not. First off, they are different, and I could find no source on which went on which side...which side for each faced inward. After using a bit of common sense, we struggled to get them to press into place. No idea why such a simple task proved so frustrating...but it's done.
The rear reminds me so some older 4 runners suffering from 4-runneritus, but replacement springs will fix that soon.
We could not drive the vehicle the day of the lift, as our torque wrench only went to 150 ft pounds, and we needed to get to 225 on the track bar and 300 on the rear leafs. A trip to the store, and we had a new 3/4" torque wrench that goes up to 300 ft pounds, so we finished things to make it drivable.
A quick test drive revealed a sound coming from the driver side, like something was rubbing. We later discovered through a bit of diagnosis that there were some extra wheel weights inboard of where they should be that were slightly rubbing on the front caliper. So swapped it with the spare and that issues was gone.
The steering wheel is off about 20 degrees, and subsequently the traction control is turned off with an error code. This affects the cruise control, etc. We have an alignment scheduled which will fix all that.
The ride results
No pulling, wandering, rubbing, noises, or any of the items one might have an issue with...other than the off center steering wheel.
On road it is compliant. Going from 80psi to 40 in the front, and 80 to 50 in the rear is night and day both on and off road. This is one of the advantages of going with the newly available E rated 37s from Falken. Before we would have had to use D rated, and rear pressure would be 65psi at the same weight per their tire techs. The added insurance due to higher capacity is a welcome offering.
We took it camping for an overnight, and only noticed after the drive that the topic of road noise literally never came up. It was one of many reasons for going with an AT vs. RT or MT. Either the tires are that good or the sound dampening is that much better. Either way we detected no difference at all. That may change over time, but it is a great starting point.
Irregularities in the road are significantly reduced, and vibration/jarring in the steering wheel from hitting them is all but gone. One could barely hear the rumble strips, nor feel them in the steering wheel. Our dog goes nuts when we brush against a rumble strip normally, and it has caused us to not be able to pass for long stretches without having to deal with significant anxiety for the rest of the trip if we do so. He didn't even notice the tests we performed.
On gravel/dirt the improvement was dramatic. Higher speeds in washboards with less heard/felt. We didn't push the truck too hard, but did push it harder than I would normally drive it for short tests. Washboards, going over yumps and bumps to test compression/rebound, rolling through washes to check g-outs, stopping then accelerating in sand in 2wd, etc. Everything dramatically better with one notable exception.
The rear shocks likely need more slow speed rebound. Head toss his increased from not much at all to some. Rear rebound in certain conditions resulted in the shock oscillating past neutral, then settling at neutral after coming back down. Increasing slow speed rebound will fix all that, and it should be dialed. Before we do so, we will put the full leaf packs on to see if some of the additional rebound is being caused by the extended bump stops. As it sits now, we're an inch away from the bumps when static. The good news, and one reason we went with this shock company, is that they offer one free tuning adjustment with their tuning service. More to follow in the next weeks once we get the replacement heavier duty leaf packs installed and do subsequent testing.
As it is spring packs have shipped, tray isolation mounts are half done, and the tunnel box that will sit between the camper and truck should be shipping in about a week. Plenty more to come.