Excessive body roll/suspension questions (1 Viewer)

[ICY80]

Running a dobinsons ims lift on my 80. Heavy springs in the rear and regular springs up front. At the time of purchase, I did not anticipate completely rigging it out with a RTT, bumpers, drawers, sliders, gear, etc. My 80 is unstable on the road and I realize that castor correction is the way to go. The top heaviness though is what really concerns me out on the trails. I just recently sold my roof nest falcon XL that weighed like 170 pounds before my solar set up, exped, and sleeping bag. Had a couple close calls that I blamed my tent for and that just made me draw the line. But after removing the tent I don’t feel all that much change. While driving and turning the steering wheel back-and-forth, you can really feel the top heaviness. I had a buddy of mine recommend putting stiffer Springs upfront. So I ordered heavy Dobinsons front springs. Do you guys think that would help? It is sitting level now, which makes me think stiffer springs would of course bring up the front. I would really not like to have a squatted Land Cruiser although we are in North Carolina

 

[Tedward]

I don't have a heavy wagon like yours but I did get a little less body lean/roll by installing a thicker/heavier sway bar in the rear.
Got it from someone here on Mud. Might have had two different brand names, Whiteline maybe.
@2KCruiser

 

[mudgudgeon]

How much lift does it have?

Caster correction won't reduce body roll, but it will make handling more predictable and stable at speed.

If you're loaded up regularly, having front and rear sway bar in action would be best.
Use extension brackets or links etc to keep them positioned as per factory install.

If springs are overloaded, you'll get more body roll.

 

[AgentOrange]

I definitely recommend going with a better rear sway bar. I don't even run one up front but a good rear sway bar will help with proper links. I did the Whiteline sway bar and Land Cruiser Phil links. If you're really loaded down often and aren't crawling, I'd go with @mudgudgeon on adding the front back in if you don't have it

 

[ICY80]

How much lift does it have?

3 inch. Should’ve stated that. My bad. Appreciate the responses fellas!

 

[Pascoscout]

You're on the edge of needing castor correction with a 3" lift. Before you drop the time and money on that take the truck to an alignment shop and see what the numbers actually are. Do this with the normal load you carry. As stated getting castor in spec won't help with body roll but it will help with wandering (which can feel like body roll). If you need castor correction go with DVS arms or castor correction plates. Avoid the correction bushings.

Heavier springs might feel like they help but it's not the right solution. They will help keep your rig from bouncing up and down like an old Cadillac but as you lean to the side one way the spring unloading can also force roll when you straighten out if your sway bars aren't up to the task.

Go with the HD white line sway bar in the rear. Upgrade the links with either LCphil or landtank. It makes a big difference. I lost my rear sway bar on a trip and ended up landing my rig on it's side the next day due to body lean. Went with the rear whiteline and way better, no loss of flex either. If you still have too much roll for your liking upgrade the front sway bar and add some drop blocks to the mounts.

Couple other things:
You might consider a rear pan hard lift bracket and/or front adjustable pan hard rod. With a lift those rods can get out of spec and cause odd handling, especially at speed or when loaded down.
Check your tire pressure. If you're heavy, running regular street pressure will add roll. Try bumping them up 5psi at a time and see if that helps.
Check your suspension bushings. If they are old or worn/damaged that will introduce unwanted movements. Replacing with OEM is the way.

 

[ICY80]

Thanks a ton. You are the man! Hate your rig rolled over. Thanks for sharing so I’ll reduce the chance of rolling mine a little. I’ll be ordering some stuff tonight. Hopefully the lead times aren’t terrible.

 

[Fosters]

What shocks are you running?

 

[77mustard40]

What shocks are you running?

Sounded like Dobs IMS in the first post.

X2 on the white line sway bar for body roll , and caster must be corrected if you want decent handling.

 

[Marvelicious]

If it were me (and it basically is...), I would order a set of drop radius arm mounts and a panhard correction kit from Eimkeith. I've got both sitting at the moment, waiting for me to get done with two months of ridiculous work schedules.

Get your geometry correct and then decide if you're happy with the ride quality.

 

[mudgudgeon]

3" lift will reduce your caster by about 5 degrees.
These had a maximum of 3 degrees from the factory.

3" lift will have put you into negative caster by at least 2 degrees, maybe more.
Front wheels will be flapping about like a shopping cart every time you hit a bump, or brake hard.

 

[IdahoDoug]

Used to develop vehicles for GM and Lexus/Toyota. As others have stated, alignment and suspension geometry are mere sideshows for correcting body roll/sway. You need sway bars and good shock absorbers - those are the suspension components that determine how much roll/sway your vehicle will have. Most people are unaware how dangerous a lift is in terms of rollover potential.

Your LandCruiser came from the factory able to do incredible emergency evasive maneuvers on grippy dry pavement without flipping. It's required to meet that standard and takes an incredible amount of engineering to achieve on an SUV. Almost certainly, any lift on an 80 now makes it possible to flip dodging a deer. Far easier than you realize. I used to evaluate suspensions on tracks dedicated to handling and would be willing to bet I could flip any lifted 80 in a parking lot within 30 seconds. That's about how long it takes to violently weave it back and forth as a test driver, and get a feel for the rebound settings, then tap the brakes, swerve, and over she goes.

I say this not to be a spoilsport, but as important information to let those who are unaware of the dangers of a lift be exposed to this issue. It doesn't get much airplay on offroad forums, and the only way you'd know this is if you had a career like mine. I get it, there are those of you who are very serious about trail use and a lift is the only way you are going to get out there. But for the rest of you, it may be wiser to spend serious money on quality trail rubber, body protection, and lockers to access the rough terrain, so that for the 99.9% of the miles you drive (on the road), you are still safe and protected by all the $$$ engineering that went into your 80. My 80 is fully locked and completely stock except for an ARB an 285 rubber and I've been through most of the trails in Moab and in all the cool places. They're uncannily competent as delivered, so strongly consider your needs.

Off the soapbox.

 

[IdahoDoug]

And a quick PS as I just re-read that.

When I say "good" shock absorbers. Many people think they can just buy a set of springs from Acme and a set of shocks from Smith Bros and they've got the "hot setup" they'll tout on forums everywhere. Egregiously bad idea. At every mm of suspension movement, the geometry changes and the spring rates change. Which means the force acting on the suspension and the leverage that force has are both changing - constantly. A shock's task is to dampen that movement without hindering it too much, or allowing it too much freedom to move so it blows through travel. That is merely ONE of dozens of considerations that go into which shock, spring rate and suspension geometry the factory chose originally, based on the CG, weight range, wheelbase, track, vehicle f/r mass & CG, etc, etc.

So thinking you are capable of saying "I like Iron Man shocks - they're the best with my lift. Or my Cletus Custom springs. Or my...." Wrong - all wrong. If these two components were to happen to work well together it would be more sheer coincidence. Does the vehicle drive down the road? Sure, but from the factory it didn't buck on speed bumps, cause the frame to shudder, cause the dash to flutter, the rears to jounce hard when empty, etc. If a suspension development engineer got into your rig to evaluate it, you'd probably see them shake their head and laugh - knowing there is no point in even starting to tell you what compromises you've made.

The way to maximize your success is to buy a matched system such as Old Man Emu who tailor both springs and shocks to work together. Anything that was not designed together is a complete crap shoot.

 

[ICY80]

LCPhil or Landtank? which do you prefer? Just ordered my sway bar from Whiteline.

 

[Pascoscout]

LCPhil or Landtank? which do you prefer? Just ordered my sway bar from Whiteline.

I went with Landtank. They work well and are pretty beefy. They are similar in design to the OEM and fit the OEM mounts on the frame (assuming you have the under frame mounts already).

A lot of people like LCPhil though too. It does look a lot beefier but is 3x the price and requires more work to install. If I ever thrash my Landtank links I may go to these.

When I lost my rear sway bar what happened is the thin washers on the factory links pushed over the lip on the link itself. This allowed the bar to drop down, catch on a rock, and get bent and torn off. The Land Tank links are a lot stronger in the area I had a failure so hoping they will last a good long time. So far so good on some serious rocks.

 

[CharlieS]

I'd reread everything above that idahodoug posted. Amazing insight and valuable information.

I don't have any credentials or professional experience, but my perspective is that these are systems that need to be properly engineered and matched. Everything is a trade off, including the stock system. Any time you modify a component or set of components, you are likely to shift that balance, often with unintended consequences.

I like to either buy a matched suspension setup, or work with someone like Ben Brazda at Filthy Motorsports who has seen untold different setups and can provide a setup that is matched to your use cases.

In addition, even without a rooftop tent, A lot of us mess with the roll center and center of gravity by adding hundreds or even thousands of pounds of cargo boxes and associated cargo, plus heavy fridges, etc. That setup can dramatically impact body roll, especially when combined with springs that aren't properly rated for the load.

 

[BucketEighty]

Lots of good info here and sounds like @ICY80 is already on the path to reduced body roll. Here's my take on what to do, in the order I would do it:

1. Install a whiteline heavy swaybar and upgraded links (I like the LCP links but they are pricey, Land Tank should work)
2. Evaluate where you are carrying weight in the vehicle and try to
   • Remove weight wherever you can
   • Move weight forward and down lower wherever you can
3. Consider lowering ride height based on
   • Tire size you're running
   • Bump stop extensions needed/used for the tires you're running
   • How much up-travel you need for the kind of driving you do
   • How much rocker clearance you need for the kind of trails you run
4. Once you pick a ride height, consider stiffer shock options. Good shocks valved correctly for your vehicle weight and spring rates can do wonders to control body roll.
5. Once you pick a ride height, consider rear panhard bar correction brackets (I like eimkeith)
6. Once you pick a ride height, consider caster correction (I like eimkeith drop brackets, my second choice would be weld-on caster correction plates)

This is the realm of detailed rig setup where you start considering exactly what you want your truck to excel at and where you're willing to make sacrifices. Next thing you know you'll be re-designing your rear drawers for improved weight distribution and spending thousands on adjustable shocks so you can dial in the tune for your weight and driving style.

 

[ICY80]

I Installed extended diff breather hoses and slee braided brake lines tonight. Still waiting on my swaybar and links to come in the mail. Got to crawling around, checking out the bushings and realized that my factory mount welded to the axle had completely separated. Somehow I didn’t notice this when I was checking my sway bar last time. That would totally explain the problem. I’m still going to install the new rear and weld up some new brackets for the driver side

 

[Delta VS]

I Installed extended diff breather hoses and slee braided brake lines tonight. Still waiting on my swaybar and links to come in the mail. Got to crawling around, checking out the bushings and realized that my factory mount welded to the axle had completely separated. Somehow I didn’t notice this when I was checking my sway bar last time. That would totally explain the problem. I’m still going to install the new rear and weld up some new brackets for the driver side

Front or rear axle?

 

[IdahoDoug]

Thanks for the kind words. I'm on a lot of forums where folks are modifying things with no idea what the ACTUAL performance change is, but lots of claims. People toss larger brakes on cars "look, I found these Audi brakes at the junkyard - my XXX stops so much better now." Uh factory brake systems take months of development by skilled teams of engineers with billion dollar labs, tracks and the like to tune out dangerous behavior. I commonly post "let's go pink slips against my stock XXX through a standard SAE testing regimen and see who wins". In 30 years, nobody's taken me up on it.

Same with offroad suspensions. Crawling uphill, encountering 8" rocks on diagonal opposite corners at 1.5mph. The factory 80 series suspension will allow its suspension to compress in damped fashion and the other two tires will maintain enough ground pressure to maintain grip and you never lose momentum. A modified suspension will cause those two 8" rock corners to compress perhaps 23% slower, causing the other two tires to briefly lose ground pressure and spin, plus the energy required to now essentially lift the entire 80 (vs simply compress two corners) will also nearly bring it to a stop (compressing overdamped springs steals energy from forward movement in a well known formula Toyota engineers yak about over lunch). Wheelspin ensues, momentum lost. Start over or engage the lockers.

The Toyota engineers literally have scales buried in proving ground surfaces to collect this data and make the 80 great. It's why in stock form they are legends and blew magazine reviewers away. 40 years ago, I still recall a day at the GM Proving Grounds we were driving cars across high speed scales at max braking to determine if we had the F/R brake system force split correct. With a driver only. Then with full GVW. With cold brakes. With hot brakes. Cornering. With the water truck soaking the track again at GVW/cold brakes/hot brakes. And the scales in the track were glass so we also took high speed photography of the tire contact patch shapes to see when we had hydroplaning on the lightly loaded rear tires. Wet/dry/max GVW, data on EACH tire's downforce to the ounce as the vehicle passed at 20mph. 40mph. 60mph. That was just one test for one piece of crap GM platform to give you perspective on how a Billion dollar vehicle platform is developed.

I mention this so you'll envision what went into your 80 from the factory. Toyota is world class - way more resources and engineer dedication than GM. Plus the 80 was a "pinnacle" vehicle for Toyota. They lavished attention on its development. And you have no idea that the vehicle you now own and modified is actually LESS competent over rough terrain, takes 20% longer to stop, will roll over in an emergency evasive maneuver, rattles your fillings on your commute to work, and sways needlessly on every curve and road undulation. An 80 Series engineer would ride in your truck for 10 minutes, get out and walk away disgusted at the unrefined, dangerous and incompetent vehicle they just experienced.

It pains me to watch all the modifications. It's kind of like paying $100k for the recipe that won the prime rib contest in the world's largest contest with the world's best chefs as tough and demanding judges. Then adding your favorite BBQ sauce. And a pinch of horseradish. A dash of salt. You get the picture.

To each their own, I say - truly. Make these girls your own. But I thought it worth sharing some perspective. Off the soapbox (again - heh...)