6112/5160 and AAL… bumpstop challenge

Alrighty, despite stressing out and researching for what seems like forever, I’m second guessing my choices.

85k miles on a 2018 TRDOR. I can feel the rear bumpstops on occasion here on Texas highways. All my parts are sitting in the sitting room, but I haven’t opened the AAL box yet. I’m worried that they’ll have minimal impact on reducing the bumpstop effect. Distance between the bumpstop and frame won’t change, so it’s only if I have a stiffer setup that I’ll see fewer contacts. In theory, the original pack plus AAL should be stiffer, but I think I’d be better served by a full new pack. I couldn’t find any full packs that were only ~1.5” lift (most were 2”+), so went with an AAL. I’m only looking for 1.5 at most.

Would a full pack perform better in that regard? I looked at the icon RXT, but was hoping to avoid that spend. It’s also 1.7” at its lowest config I think.

Any input is appreciated.

 

I just had this same setup done yesterday. I think you will be happy with the RXT - which is what I got. I went with setting 2 because I have a camper top, but I believe setting 1 will give you the amount of support in the back without too much lift. I didn't want more than 1.5" myself. My installer told me (and I listened) that every time he put an AAL on someones truck, they always come back within the year to have full leaf packs put on.

 

This is Icon RXTs on option 1. It’s sitting right around 1” over stock (no lift in the front). I also have bed drawers which are another 100-150lbs. Option 1 would work great for you I think once they settle completely. I’m probably gonna end up at option 2 eventually.

 

Ugh…. Decisions decisions. All the info says RXT option 1 ends up with 1.875 lift. Add 1/4 for shims and you’re over 2.0. Maybe back to 1.75 with settling.

If I opt for the RXT, the only solution to drop height is 100lb of sand in the back.

But I am nervous about the ‘they always come back for a full pack’.

 

For what it’s worth, I’m not running any shims in mine and it’s smoother than it was stock. I always had a 30-10 braking vibration and it’s gone now

 

RXT option 2... got installed 2 years ago. With the weight of a canopy started out around 2.25 lift... now is about 2". If/when it settles another 1/4" i'll be back the the factory rake of 1.75"... perfect imho. I throw in 200lbs of sand each winter and doesn't seem to drop it much... maybe 3/8". I've read option 1 will sag pretty quick with weight... something to consider.

 

FWIW I was thinking I would go with option 1 on the leaf pack since I didn't want a lot of lift, but my installer said it would basically be stock height because of my camper top and would sag under weight once I've loaded up the bed. Ended up going with option 2 because I figured I'd rather have a little more lift than I wanted than a little less. Just remember that every truck is different and no two situations are the same - so what works for everyone else may not for you. The nice thing about an AAL is that it's a fairly low-cost solution to try first - especially if you are doing the install yourself. In my case, I couldn't do the install, so the labor would be exactly the same for an aal or entirely new leaf pack. Buy once cry once I guess. Have to say though, now that I've had a few days to get used to it, I think it looks really good - and not obnoxiously high. Here are before and after pics.

 

Appreciate that. I rarely tow, and more times than not when I put weight in the back it’s 15 bags of mulch…. So maybe 400lbs.

Now that I have the AAL already, I’m pinched for cost to return them. UPS estimator was like $80 I think.

I *might* be able to sell them locally for less loss than that.

 

Mine’s the reverse apparently. A little bit of vibe on braking 25-15. No issues before lift. Story of my life…. I never get the easy route.

 

If you already have the $hit, I’d install it and go from there.

There’s always FB Marketplace if you want to swap it out later.

 

@Diablo169 It went in over Thursday and Friday. Took me longer than I expected, which I expected.

Got about 3” of lift over ‘as is’. I’m hoping everything settles in over the next few months. I like a little rake, so am hoping the rears settle a little and I can pull the front suspension and drop a clip or two. I’m going to have to add axle shims I think, so figure I’m going back up 1/4” when I do.

 

Here’s the best I have for a before and after comparison. Hoping to get a little relaxation out of the rear leafs. She’s definitely sitting a little taller than I’d hoped. And yep, it’s the same paint job lol. Inferno just changes so much based on lighting.

 

Measured my angles this afternoon:

Spent about 5 minutes with the truck in neutral rocking it back and forth to get the u joints as level as possible. Got them to within 0.2 degrees.

1. Zeroed my level on the flange off the transmission: 0 degrees
2. Measured first u joint 3.2 down
3. Measured first shaft 3.0 down
4. Measured second u joint 2.9 down
5. Measured second shaft 5.0 down
6. Measured third u joint 0.7 down
7. Measured pinion gear flange 0.2 down

In theory, certain u joint angles and shaft or flange should match, eh? If I use the flanges and actual shaft angles, this is what I have from an online calculator. (I ignored the actual u joint angles assuming some uncertainty). With 5.2 degrees working angle of my last joint, I’m inclined to seek at least a 3 degree shim. However, with my front and rear flanges being within 0.2 degrees, isn’t that pretty optimal overall? Would it be better to do a CB drop which would make my angles closer to 4, 1, 4?

I’d prefer to avoid any more lift (shims) if possible.

 

It’s easy to overthink your way into spending money. Give it a few weeks of driving to see how it all settles and go from there. Chances are good it will be adequate enough and you can always change parts later as needed. I went through several suspension iterations on my Tacoma over 7 years of owning it.

 

The stock CB bolts are long enough to add washers to lower CB. You can do that to actually fine tune instead of just chucking a big shim in there. Give it some time to settle and re measure your angles.

 

U joints aren't made to run at 0. there's a 3 deg operating range.
Working angle 1 should be less than .5 ideally but no greater than .8
Working angles 2 and 3 should be the same and both under 3 deg.

 

Thanks everyone for the comments so far. I’m about 2 weeks into it, but haven’t driven it more than 150 miles.

Working angle 1: While I didn’t measure before the work, that angle shouldn’t have changed based on my lift, correct? That’s the angle between the transmission and the first shaft. CB drop would make that worse. Diff drop would make that better?

As it sits now, a 2 degree shim would get me *close* to 3 degrees for the pinion angle. But in theory, that would introduce an overall ~2 degrees between the transmission flange and the pinion flange. How important is it that the overall combined angle is near zero, regardless of what the individual angles are?

I’m going to put a few hundred more miles on it and see how it feels. I do feel like it’s lessening a little as time passes…. But that could be wishful thinking too.

 

RXT is better than AAL. Icon progressive AAL is better than a regular AAL and costs the same new as an RXT pack which is $300 used.

Deaver and Archive packs may be better than RXT but cost more and may be more specific.

RXT seems universal in having 3 options. People say op1 goes flat and to avoid it.

mine is set to Op3 because that’s what the previous owner set them to and I’m not sure if there’s any legit reason to go back in there wrenching to make it Op2.

OME sells a CB drop kit for lifted trucks. And if you upgrade to a better CB you can put it to whatever height you want.

 

If your truck is on level ground then measure again 'without' zeroing the level on the flange and punch in the new angles. See what you get.

 

Are the u joints themselves safe to measure if aligned vertically, or should I just go with the shafts and flanges directly?