Post Torsion Bar Adjustment Handling (1 Viewer)

[4Peanut]

Help/Advice: Post Torsion Bar Adjustment Handling

Let me start by stating that I have read countless threads/posts about cranking the front OEM torsion bars, droop, etc. My question relates to post-crank handling. But first, some background:

1. 2003 Land Cruiser. 105,xxx miles. Stock front/rear suspension.
2. 1.5" coil spring spacer added to rear.
3. Front torsion bars cranked to level.
4. Static fender-to-rim measurement: 11"
5. Full droop fender-to-rim measurement: 13.5" (2.5"/63.5 mm of droop)

My initial around-the-block test drive to settle the suspension after installing the spacer and cranking the torsion bars revealed an extremely "light" front end. So much so that under hard acceleration in a straight line the front tires would squeal for as long as I would let them and the steering wheel would jerk left and right (similar to front wheel drive torque steer). My droop measurement immediately following this test drive showed I was right at 2" (50.8 mm). I lowered the front by one full turn of the torsion bar adjusting bolt. The ride is only slightly improved and I currently have the static/droop measurements above.

Understandably, raising the front produced a lot of static positive camber, which only increases as the load on the front tires decreases (i.e. the tire droops). Add to this the fact that my Bridgestone Dueler H/T's are at their treadwear markers, and we have a Land Cruiser with reduced tire contact even while standing still.

On to my question. Given the favorable droop measurement, should I replace the tires, get an alignment and take another test drive before making any further adjustments to the front torsion bars, or is there something else at play here? As always, your experiences and advice are greatly appreciated.

 

[spressomon]

You have some thick rear coil spacers/packs there! Front to rear rake is usually set at 1"; what is your's? If you lift the front end enough you will get progressively more torque steer and funky handling traits compared to stock height; sounds like you might have too much front lift height.

If your tires are worn as you state you'd want to get new tires and run them for, say, 50-miles then take the truck in for a front end alignment. Theoretically anytime you change the front lift height and/or any front suspension components you want to get it realigned...

 

[4Peanut]

spressomon, thanks for your input.

I had originally adjusted the front torsion bars months ago just to level things out—I am not a fan of the raked look. In the months and thousands of miles since, I had never experienced the handling issues I am now (see original post), even with the rear loaded down with kids and bikes. Prior to installing the 1.5" rear coil spring spacer and adjusting the front torsion bars this past Monday, my measurements—from garage floor to fender lip—were:

DS Front: 34 5/8"
DS Rear: 34 3/8"

PS Front: 34 1/2"
PS Rear: 34 5/8"

So, before any changes Monday, the 100 sat pretty level. There was noticeable, yet not exaggerated, static front positive camber, but since the Bridgestone Dueler H/T's only had a few miles left on them anyway, and I would be replacing them and getting an alignment soon, I didn't worry about it.

My current measurements—again from garage floor to fender lip—after installing the 1.5" rear coil spring spacer and further adjusting the front torsion bars are:

DS Front: 35 1/2" (+ 7/8")
DS Rear: 36" (+ 1 5/8")

PS Front: 35 3/8" (+ 7/8")
PS Rear: 36 1/4" (+1 5/8")

Full droop fender-to-rim is currently 13.5" (2.5"/63.5 mm of droop), and the 100 now sits with about a 1/2" rake. The static front positive camber is now significant. I know it needs an alignment, I just want to make sure there isn't something else at play here that a set of new tires and a proper alignment won't fix. My tire size choice is somewhat dependent on the lift I achieved on Monday.

I'd love to hear from some others too. Thanks.

 

[CrusrDug]

I have the same symptoms and it freaks me out when that steering wheel goes back and forth like that. I have it adjusted now to where I really have to get on the pedal to make it happen, but it isn't completely gone. I have a 30mm rear spacer and I have cranked the torsion bars in front, but they are currently only one turn on the bolt. My tires are warn and need replacing. Here's the kicker....I have AHC too.

My solution- I'm taking it back to stock and turning it in to a real mall cruiser by giving it to the wife and new baby on the way!

Then I'm going to Ford and dropping $$$ on a new Super Duty Diesel. BOOM- fixed my towing problem for good.

 

[FullyLitLED]

You have some thick rear coil spacers/packs there! Front to rear rake is usually set at 1"; what is your's? If you lift the front end enough you will get progressively more torque steer and funky handling traits compared to stock height; sounds like you might have too much front lift height.

Like spresso said, 1" rake is normal. I had the ride level for a while but now I lowered the front a little due to harsh speed bump riding. The ride is better stock, but a 2" lift is better than a soft ride lol I think I have the front set at 21.5" fender to hub while the rear is at 22.75" fender to hub

 

[wildsmith]

A diff drop should help with the torque steer a bit and is fairly cheap and easy to install.

 

[4Peanut]

A diff drop should help with the torque steer a bit and is fairly cheap and easy to install.

wildsmith, thanks for your suggestion. Since others are running as much or more front lift without a diff drop and have not reported the same handling characteristics, I assumed it was something else. It sounds like the diff drop would help the torque steer, but what about the lightness in the steering? I really need to get an alignment—I've got so much positive camber the 100 looks like a Nationwide truck—but I'm still trying to pull together my tire decision/purchase.

On that note, I'd love to put BFG All-Terrains on the 100—I had two sets on my 4Runner and loved them—but while the 4Runner was "my" car, the 100 is now the "family" car. We'll be driving 50 hours and 2,874 miles in the next five weeks. I'm thinking Nitto TG's or Bridgestone Revo 2's would be a better option for me. But part of me is afraid I'll forego the BFG's and then regret it for 40-50,000 miles.

 

[wildsmith]

I don't know if some people might be more willing to lay off the gas pedal and live with the torque steer than me but I found the diff drop almost eliminated torque steer (foot to the floor at low speed it will still try and pull the wheel a bit). From reading various places I think worn steering rack and front upper control arm bushes can make it worse as well.

I think you need to get that alignment looked at though because that might solve most of your problems.

 

[spressomon]

The other issue I discovered late last year that can exhibit torque steer type symptoms: Worn rear upper control arm bushings. Probably not a concern for lower mileage 100's but mine were shot and the symptom was something was wrong with the front end as it developed, almost overnight, progressively worse torque steer...until it got to the point of being semi-dangerous to drive at highway speeds.

 

[4Peanut]

spressomon, the torque steer only exhibits itself under hard acceleration, usually from a stop or slow speed. At cruising speeds—whether at 30 mph or 60 mph—there is no torque steer.

Speaking of rear control arms, based on a quick search here and a look at the FSM, my rear lower control arms aren't supposed to look like this, are they? They have looked like this since I bought the 100 in May 2009, and since they were evenly bent, I assumed they rolled off the showroom floor that way. Now, I'm thinking they had a run-in with a hoist.

 

[2000UZJ]

spressomon, the torque steer only exhibits itself under hard acceleration, usually from a stop or slow speed. At cruising speeds—whether at 30 mph or 60 mph—there is no torque steer.

Speaking of rear control arms, based on a quick search here and a look at the FSM, my rear lower control arms aren't supposed to look like this, are they? They have looked like this since I bought the 100 in May 2009, and since they were evenly bent, I assumed they rolled off the showroom floor that way. Now, I'm thinking they had a run-in with a hoist.

those are definitely bent

Those might be the toyota high clearance arms shotts didn't get!

Looks like somebody went to rotate or get new tires and the shop used those to jack the truck up. The guy at Big10 almost did that, I caught him in time and told him not to use those. Retards...

 

[spressomon]

^^^as he said . Replace them before you take it in for alignment. OEM is fine. If you're planning on wheeling the rig in rock country especially I'd do the reinforce mod to them to strengthen them...or maybe if you're going to take it back to whomever you think bent them you should do the reinforce mod anyway

 

[farinvail]

Take the lower control arm off and sledge hammer is back mostly straight and put it back on with the bow facing down. Eventually you will hit it on a rock and it find it's way back to perfectly straight.
They don't align the rear anyway so it doesn't really matter.

 

[ShottsUZJ100]

If your tires are worn as you state you'd want to get new tires and run them for, say, 50-miles then take the truck in for a front end alignment. Theoretically anytime you change the front lift height and/or any front suspension components you want to get it realigned...

***Excellent advice. Draw no conclusions unti you get an alignment. And since your tires are beat, get them first.

A diff drop should help with the torque steer a bit and is fairly cheap and easy to install.

***I've not seen any changes after a diff drop. That's from only 3-4 100's I've helped here in town though.

On that note, I'd love to put BFG All-Terrains on the 100.

The mags didn't call the 100 Roklimo and Trailimo for nothing. With the AT KO's the thing was still an amazing truck to take on LONG distance rides. The KM2's are beginning to irritate me as they age. The sounds and vibes now a year later have me thinking all my driveline bearings are going out. Get them! Spend the dough! You already know they are worth it!

The other issue I discovered late last year that can exhibit torque steer type symptoms: Worn rear upper control arm bushings. Probably not a concern for lower mileage 100's but mine were shot and the symptom was something was wrong with the front end as it developed, almost overnight, progressively worse torque steer...until it got to the point of being semi-dangerous to drive at highway speeds.

***YES! Check that stuff out too BEFORE the alignment. Grab everything underneath and see waht moves/gives.

Take the lower control arm off and sledge hammer is back mostly straight and put it back on with the bow facing down. Eventually you will hit it on a rock and it find it's way back to perfectly straight.
They don't align the rear anyway so it doesn't really matter.

***Good way to bend back bent arms, however BAD advice as far as alignment goes. The rear axle CAN and WILL steer the vehicle if it is out of alignment. Until it is fixed you could chase your tail on the front end to NO END. We're taking in our 2005 Matrix in for this right now! It needs a Shim Kit installed to correct a bent rear arm (cheaper than buying a new rear arm). Hit a big box of something on the freeway and it bent a rim and arm. It pulls to the left 24/7...it NEEDS a REAR-END alignment. If you are going to buy arms, these are unbeatable! And...they use Toyota rubber bushings instead of the poly crap. (my opinion...please no hate posts...but, ah what type of bushings does Toyota use?)

 

[4Peanut]

Thanks for your input John!

I've already got a call into American Toyota for new, OEM lower rear control arms, and new bushings for both the upper and lower rear control arms. I'll get all of that replaced, mount up some new tires and then get it aligned before making any more changes to the front torsion bar settings.

 

[ShottsUZJ100]

Thanks for your input John!

I've already got a call into American Toyota for new, OEM lower rear control arms, and new bushings for both the upper and lower rear control arms. I'll get all of that replaced, mount up some new tires and then get it aligned before making any more changes to the front torsion bar settings.

Any time!

Ahhh....they don't sell the bushings. Need to buy new arms which include new bushings.

When you hear the OEM lower arm price you'll be calling Wild West for my arms. Oh, and if you do go with WWOR lower arms make sure you tell them you want STOCK length.

 

[spressomon]

Any time!

Ahhh....they don't sell the bushings. Need to buy new arms which include new bushings.

When you hear the OEM lower arm price you'll be calling Wild West for my arms. Oh, and if you do go with WWOR lower arms make sure you tell them you want STOCK length.

Is WWOR offering 14mm bore on these? Or will he have to convert to 18mm?

4Peanut, one other thing to know: The lower control arm mounting bolts are designed as a single use part. I discovered this in the school of hard knocks... The bolt head has a raised ridge star pattern that serves for lock/anti-loosening. Its relatively easy to either roll these ridges partially or completely thus ensuring you will be searching for replacements after they exited without warning. And this occurs out in the middle of no where....

So either replace them with OEM or move over to bolts with locking style nuts to be sure they'll go the distance.

 

[ShottsUZJ100]

Is WWOR offering 14mm bore on these? Or will he have to convert to 18mm?

18mm (80-series) which is another plus...

Larger bushing
Larger bolt
Greater diameter arm

Needs $10 in parts.

 

[spressomon]

18mm (80-series) which is another plus...

Larger bushing
Larger bolt
Greater diameter arm

Needs $10 in parts.

The bushing OD is the same...only the bore changes.

 

[ShottsUZJ100]

The bushing OD is the same...only the bore changes.

Yes yes.....correct. Thanks!