recent thoughts on my 4:88's, Tundra LT suspension & 35's (1 Viewer)

[linuxgod]

@TexAZ, I'm thinking your issues might have been exacerbated by the fact that the Tundra CVs and arms are longer. What normally might've been "within engineering spec" when the UCA was pushed fully forward with shorter LC suspension geometry was too far out of spec when the changes were magnified by the longer arms.

For those having trouble visualizing, as an exaggerated exercise point your finger straight forward, and then move it left and right. The tip of your finger follows a much longer arc than your knuckle, so 1" of movement at the knuckle becomes 2" of movement at the tip.

 

[TeCKis300]

@TexAZ thanks for those details and clarifying!

In doing the Tundra arms, should the 4WD Tundra parts be sourced? Or is there no difference between 2WD and 4WD?

 

[TexAZ]

There is no difference between 2wd and 4wd on control arms or tie rod ends.
If you are looking used, sequoia parts are the same as well.

 

[duggy]

the frame modification is very common on Tundras. it does require cutting, welding and painting.
adjusting the lower control arm cam bolts can be done in the driveway with minimal tools.

The rub was so minor, an easy adjustment took care of it.
I honestly had no idea the arms offered as much movement as they do, or I would have been much more specific with the alignment shop.

simple solutions and lessons learned.

Understand, and glad you got the issues figured out. The problem that we run into is that you at times run out of adjustment at bottom cam bolts. If you positively adjust caster at the top (SPC) you actually move the wheel backwards towards the firewall. Adjusting them at the bottom cam bolts effectively will move the wheel forward. This is where the body mount chop comes into play, but we are working with different chassis, so I understand how it may be necessary on the 120 Series where the body mount protrudes much more than the Tundra/200 series.

 

[Mogwai]

@TexAZ, I'm thinking your issues might have been exacerbated by the fact that the Tundra CVs and arms are longer. What normally might've been "within engineering spec" when the UCA was pushed fully forward with shorter LC suspension geometry was too far out of spec when the changes were magnified by the longer arms.

For those having trouble visualizing, as an exaggerated exercise point your finger straight forward, and then move it left and right. The tip of your finger follows a much longer arc than your knuckle, so 1" of movement at the knuckle becomes 2" of movement at the tip.

It's all Tundra parts, the CVs are longer, Tundra lower and upper arms (meaning Tundra SPCs), so are the Tundra spec'ed suspension components. There are no LC spec parts on the front.

 

[Markuson]

I'm waiting for my brakes to wear out before I upgrade, but I haven't felt any significant difference when braking between 31s and 34s. I'm sure there is a difference in distance, but the pedal feel is similar to me. And I can still lock up the ABS at 70mph on the highway when some dumbass trying to merge jumps 2 lanes at 30mph right in front of me. So yeah, what you said about driver's ed...

In my experience, it’s not so much a difference in brake feel as it is a propensity to overheat quickly.

Coming down mountain declines, I use engine braking WAY more...out of necessity.

 

[TexAZ]

For those having trouble visualizing, as an exaggerated exercise point your finger straight forward, and then move it left and right. The tip of your finger follows a much longer arc than your knuckle, so 1" of movement at the knuckle becomes 2" of movement at the tip.

the distance the wheel moved forward was greater with the Tundra set up than it would have been with the cruiser parts, but the angles are the same. The inner joint simply does not have the same ability to operate at the angles the outer joint does.

 

[TeCKis300]

Edumacate me please. Is a stock Tundra's geometry out of whack? Or are you saying front to rear there's a mis-match in geometries? Does changing stock front end geometries with wheel offset and spacers not affect "roll resistance"? Does a body lift raise the COG less than the equivalent spring lift? I'm sure these could all be SQODs which is why I'm asking.

Not saying the Tundra geometry is out of whack. What we don't know is when the Tundra arms when fitted to the LC, whether the full suspension travel or steering lock go beyond what's healthy for the CV joints as spec'd for the Tundra. Perhaps someone does know, but are the stops governed by the Tundra arms or the LC hubs/stops? Only time will tell without OEM levels of validation or modeling.

Roll resistance is built into the geometry of the IFS based on the roll center and down angle of the arms. When one raises (or lowers) the suspension, this optimal angle and it's resistance to roll is lost. Which is why lifted vehicles tend to need significantly higher spring rates to regain stability. Not only is roll resistance lost, but lateral loads will translate into vertical jacking/sagging force (i.e. bad handling manners). Fortunately for a more extreme lift, the Tundra long arms actually help this situation.

Wheel offset plays into a bunch of things, most importantly the scrub radius. It's somewhat independent of the arm length and more correlated to tire diameter. Larger diameter tires matching slightly lower offsets. Hence why you see the rock warrior fitment as 50mm for clearance, but also to retain scrub radius geometry for 32.5" tires vs stock 60mm for 31" tires. You can extrapolate this roughly for 34s and 35s.

 

[Blasst]

What year is your Cruiser? (I'm assuming 6-speed tranny?)

What are you looking for out of long travel front suspension?

From one turbo-head to another.

If you want an aggressive setup, I would prioritize tire height. That is true lift as it's the only parameter that increases clearance under the axles. With 4.88's and 35s, you'll still be at better than stock gearing with the 31s. So you'll still have snappy performance. Something closer to a 34, would be ideal for a cruiser, as it minimizes interference and needing to limit travel type issues.

In terms of handling, keeping the suspension geometry and lift close to stock as possible, with big tires, is the way to maximize performance. As it doesn't compromise roll resistance geometry and keeps bump travel alignment changes as minimal as possible. Which is why I suggest lifting more via tires. Then do a mild lift (1"-2") via suspension.

With the taller tires, you'll want to add a bit more width to the track. Not necessarily via Tundra long arms. Wheel offset, either by spacers, or new wheels, aiming for something in the 30-45 offset range would be ideal. To optimize scrub radius geometry, but also to regain some lateral stability. Without going so far in offset that it starts degrading geometry.

If someone were to desire more lift then tires and suspension as proscribed above, then I'd do a minimal (.5"-1") body lift. This keeps the suspension geometry still optimal, keeps the center of gravity low, while gaining more vertical height in clearance for bumpers and potentially 35's.

This staggered lift strategy and modifying the vehicle as a "system" is the way to go IMO. Long travel front suspension can still make sense if your goal is to chase Raptors and baja running through whoops, where travel is king. FYI I suspect based on some anecdotal reports that there is some binding in the CV at steering and articulation limits with the tundra setup on the LC.

Hey thanks for all the input from everyone.
Interesting thread has sprung up from my ramblings. Kinda what I hoped for since I am still in the decision process and like to hear ideas and experiences on the LT suspension versus just adding taller tires for clearance.

@TeCKis300 yes 6 speed tranny. I have a 2014 LC. I suppose my goals are both clearance and wheel travel although I am not planning on chasing Raptors or doing high speed desert bombing. (would truly like to though not with this rig)

I have a 2" lift with my current PR-51 setup. At the moment I am leaning toward simply putting some 34" tires on for a while and going that route....especially since the setup hasn't even gotten a good pounding and I have just in the last 2 weeks gotten my 4.88's broken in.

I like the idea of LT suspension not for high speed so much but just the increased wheel articulation for rough trails. Though once again I feel I should add 34" tires FIRST & then push my current setup a little on some challenging trails. Then I might decide to go LT setup and appreciate the suspension more and care less about spending the coin.......or might find I am happy with 34's and the BP-51's which I suspect at the moment will be the case. Also it is a good excuse for me to pack a bag and a woman for an emergency trip somewhere and have a little fun on some trails.

I'll wait for Jasons bumpers and my Budbuilt skids which should arrive shortly.

Thanks for sharing your thoughts...great chart btw,
Jim

 

[NLScooby]

are the stops governed by the Tundra arms or the LC hubs/stops?
.

The Tundra LCAs have the stops to limit the steering (IIRC).
I’ve just ruined my Drivers Side CV on a new Tundra axle I bought from Toyota- only 5K mileson it and 1 off-road trip. I’ll be checking that alignment this weekend to see if the shop pushed the LCA forward for some reason ( I’m only on 33’s)....

 

[TexAZ]

The Tundra LCAs have the stops to limit the steering (IIRC).
I’ve just ruined my Drivers Side CV on a new Tundra axle I bought from Toyota- only 5K mileson it and 1 off-road trip. I’ll be checking that alignment this weekend to see if the shop pushed the LCA forward for some reason ( I’m only on 33’s)....

snap pictures of the lower control arm cam bolts, from the front and the back. their position will tell you if the arms have been pushed forward.