Wheel alignment Qn - interference between LCA and rod ends

[skit]

Hi,

I have just changed the setup in my sprinter and have found some clearance issues when doing my roughy home wheel alignment. In a nutshell, the tie rod end ball joints touch the back side of the LCA's before I reach full lock in the rack. This inhibits the amount of lock that I now have (& partly defeats the purpose of the mod).

OLD setup was: xt130 LCA's, adm steering arms & standard 86 tie rod gear.

NEW setup is: sigma LCA's (press in ball joint), jdm power steering arms, old corona tie rod ends & tie rod outer tubes. Almost certain the tie rod gear is the same as ra40 celica but it's all my wrecker had.

Car has an adm rack & rack ends, unchanged in both setups described above.

Note that the problem I saw was with the front end up in the air and the suspension at full droop (I know you aren't supposed to do alignments this way, but it's the best I can manage at home). I run short stroke HTS dampers so there's not much droop anyhow.

With the wheel alignment toe set fairly close (but not exact) I noticed I had just under 3.4 turns of the steering wheel lock to lock. I'm fairly certain I used to have 3.5-4 turns, so I checked to make sure everything was moving freely & not interfering. Turns out that when I try & turn to full lock, the tie rod ends swing around and come into contact with the rear side of the sigma control arms.

Example: Turning full lock to the left. The LHS steering arm & tie rod end swing to the right (as they are pulled by the rack & tie rod) until the ball joint of the LHS rod end contacts the back of the LHS control arm. This happens turning both directions, not just to the left.

I suspect this problem would not occur if I used normal adm steering arms, as the standoff distance between the tie rod & control arm is longer (due to the 10mm longer steering arm). The problem can be dialled out by adjusting the tie rods longer, but obviously this adds toe-in the point of being useless.

Is anyone running this setup in their cars or seen this happen? My car is straight, never had a problem with alignments before. There is a possibility that this problem will not exist when the car is dropped on the ground and the suspension compressed, but I doubt it. I will check that tonight.

Cheers.

[biggo]

i see kinda

have you tried RCA's? they might give you enogh room to allow the steer arm all the way in. Failing that, try some aw11 tie rods, they have both ends open so you can wind both the rack and tie end to get the travel you need.

If all that fails, go back to rona lcas and get camber tops?

[skit]

<div class='quotetop'>QUOTE (biggo @ Mar 19 2008, 01:22 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=504373)</div>
i see kinda

have you tried RCA's? they might give you enogh room to allow the steer arm all the way in. Failing that, try some aw11 tie rods, they have both ends open so you can wind both the rack and tie end to get the travel you need.

If all that fails, go back to rona lcas and get camber tops?[/b]


Thanks. I should clarify, I have cambertops & RCA's. Changing camber doesn't help much. I have the cambertops set 100% positive at the moment, which looks like around 1.5 degree of negative camber.

The corona steering gear I used has plenty of adjustment, easily enough to set the toe correctly.

Upon thinking more about it maybe I don't have a problem, maybe its just how it is - the sigma arms have no lock stops on them.

However it would be nice to know if 3.5 turns lock-to-lock with ps arms gives more lock angle than 3.75 turns lock-to-lock with adm steering arms though. Not sure of an easy way to measure it accurately, and I don't fancy putting the old gear back in just to try & measure it.

Surely other people are running a similar setup?

[biggo]

how much lock do you actually have?

as you said, it may be just how it is, and from what i can gather youve probably got moree than enough

[skit]

<div class='quotetop'>QUOTE (biggo @ Mar 19 2008, 04:12 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=504454)</div>
how much lock do you actually have?

as you said, it may be just how it is, and from what i can gather youve probably got moree than enough[/b]

Well, in hindsight I should have done a visual check to compare the lock angle I was getting before I changed to the new gear.

I also should have mentioned that the car is not running at the moment, so I can't simply chuck a ewy and feel the difference.

It looks like it has reasonable lock, its just that for all the talk about going to jdm power steering arms, I've never heard anyone say anything about them physically limiting the movement of your rack.

So - who's got power steering arms with your manual rack, & can you turn the steering wheel a full 3.75 turns?

[federal]

no you can not turn the rack the original 3.75 turns....

the ps arms are shorter which reduces the amount you need to turn the steering wheel for the same amount of lock, this in turn gives you more lock....i have run PS arms many times now and the lock is improved etc etc....

if your steering knuckles did not hit you control arm then you could run into strife RATHER quickly....i.e. the rack would become aligned with your tie rod and then you wouldn't be able to turn back....

i have had scenarios in which my steering knuckle has come to rest on my swaybar links....this is the furthest you would want it to go in reality as this puts the rack and tie rods only a few degrees away from aligning and jamming....

hope this answers any queries

[Hen is a total nutcase]

The issue of tie rods hitting on the LCA isn't a problem in itself. My front setup does that too. It's probably not the best, and annoying because you know there's more lock to be had from the rack if only it could move more, but isn't disasterous.

And as Mr Fed says above, sometimes you need to limit travel so your tie rods and steering arms don't move so far they make a straight line.

I'd say don't worry about it, and when you can, take it for a drive and see how you like it.

Hen

[skit]

Thanks Federal & Hen.

I understand what you mean about the need to limit the lock to prevent the steering arm & tie tod becoming a straight line and refusing to turn back the other way.

I checked out steroids' setup last night with s13 gear, and he gets just over 3 turns of the steering rack, but heaps of lock.

I guess its no problem - as you said Hen, it's just a bit annoying that there is slightly more lock to be had but it can't be utilized.

Cheers for the help.

scott

[ninja_86]

mine fouls the LCA before the rack ends bottom out, but i still have heaps of lock to drift with....

thats with sigma control arms, ae86 struts etc.....

[skit]

<div class='quotetop'>QUOTE (ninja_86 @ Mar 21 2008, 10:46 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=505670)</div>
mine fouls the LCA before the rack ends bottom out, but i still have heaps of lock to drift with....

thats with sigma control arms, ae86 struts etc.....[/b]

Thanks ninja, sounds like its the norm. Can't wait to drive the thing again. btw - did you drill new swaybar mount holes in your sigma LCAs? I didn't, and while everything bolted up, the 6mm or 8mm dia studs that connect your swaybar to the LCA are at a fair angle, and the rubbers are under constant stress - mine are fairly old & I reckon they will split after some driving.

In the threads on sigma LCAs I haven't seen anything about redrilling the mount hole, but I think I might. Did you?

[anastasios]

I'm guessing you used gh sigma arms? it probably would have been better to stick with something shorter

[skit]

<div class='quotetop'>QUOTE (anastasios @ Mar 22 2008, 03:08 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=505881)</div>
I'm guessing you used gh sigma arms? it probably would have been better to stick with something shorter[/b]

Yes GH model arms.

Why would it be better to go shorter? I already had corona arms & wanted more track cheaply & without using dear neg offset rims.

When using RCAs and cambertops, there is nothing extreme about the sigma arms. I have the cambertops set full positive & I have an estimated 1-2 deg neg camber, which is slightly less than I used to run.

The front end looks nothing like some of the photos I've seen of cars with sigma arms & standard strut tops giving bullshit stupid neg camber. Its looks perfectly reasonable to me.