SAS steering issues

[Bagdad mafia]

Hey all,

I have recently installed an 80 series front end into my 4runner and having some teething issues with the steering,

Im running a custom 3link front running 2 lower arms and one upper arm located on the passenger side

now the problem is the steering wont self centre after steering input and also when powering on the car steers left and powering off the car steers right

Now the toe in is set to 8mm but the castor hasnt been set accuretly its set at around -4degrees with a magnetic pertractor at the kingpin bolts.

any one have any ideas on how to get it to steer 100% ?

thanks for any input.

Gavin.

[Rory]

Is the upper link trianglated at all?
If not, it maybe due to poor lateral support.

[Bagdad mafia]

no its not triangleated as it has a panhard rod

[Rory]

arh ok too easy!
Is the panhard rod in line with the steering tierod?

[Bagdad mafia]

yeah they are parralell to one another

so shouldnt have bump steer either

[RUFF]

Post a pic from the front of the Panhard rod and steering sitting on level ground. What you describe sounds like bump steer to me. Or your bushes are all to soft and the axle is wrapping.

[Rory]

Thats my guess too, I wouldnt have thought castor angles would affect the way the car acts under straight line accel and decel, only cornering. ( I could be wrong, have never really had much of a look into it)

[RUFF]

Thats my guess too, I wouldnt have thought castor angles would affect the way the car acts under straight line accel and decel, only cornering. ( I could be wrong, have never really had much of a look into it)

Correct but if the axle rolls back and forth it could also cause these symptoms. And its quite possible with only one top link.

[RN]

Hey all,

I have recently installed an 80 series front end into my 4runner and having some teething issues with the steering,

Im running a custom 3link front running 2 lower arms and one upper arm located on the passenger side

now the problem is the steering wont self centre after steering input and also when powering on the car steers left and powering off the car steers right

Now the toe in is set to 8mm but the castor hasnt been set accuretly its set at around -4degrees with a magnetic pertractor at the kingpin bolts.

any one have any ideas on how to get it to steer 100% ?

thanks for any input.

Gavin.

Easily fixed, return it to standard just as Mr Yota designed it.

I have nothing usefull to add to this thread.

[Rory]

Good point, I didnt think about that.
From memory, if you want it to self centre you need positive castor, more positive castor gives heavier steering.

[Struth]

8mm of toe in sounds a bit extreme, 60 series only calls for 2mm, is the 80 different?

Some pics would be good but it sounds like you are using control arms and not radius arms, so therefore only one bush connected to the axle at the end of each of your three links?

If so the steering caused by acceleration and deceleration wouldn't surprise me as the driver side is relying on one single bush to keep the axle at right angles to the chassis and this bush would be taking a lot of load and compressing heaps.


But pics are really needed, who can tell without actually seeing the geometry of what you have fitted..

Cheers

[joeblow]

Im running a custom 3link front running 2 lower arms and one upper arm located on the passenger side



Gavin.

why do people do it that way. it would have to be one of the worst ways to do a front.......oh.....but i guess its easy!

[Bagdad mafia]

here are the best pics i have at the moment

[Mr DJ]

It might be the pics, but panhard & draglink dosen't look parallel to me.
The line to look at on the panhard is the between the centre of the mounting points not the rod itself as it has a bend on the end to clear the origonal radius arm mounts.

A pic from directly front on with the wheels pointing straight ahead would be better.

[Struth]

Panhard and draglink look close enough to me, much closer than mine are and I don't get any scary bump steer.

I agree with Joe though, I don't know why you would do it that way it is just asking for trouble IMO and the relationship between where the lower control arm attaches and the centre line of the axle looks way to close for my liking.

Is this a common method????


Cheers

[lukethedork]

why do people do it that way. it would have to be one of the worst ways to do a front.......oh.....but i guess its easy!

Joeblow.
A 3 link + panhard is fine, Infact it is alot better than 'fine'. I would be willing to bet the two suspension types that win the most rock crawling competitions are 3-link + panhard and triangulated 4-links (not 5-link). That being said, Using soft bushes will not work well with this suspension setup.

Please tell me what suspension setup you think would work better with mechanical steering, Joeblow? A 5-link that binds up when articulated?

Struth, Yes this is a common method of setting up the suspension. I bet he's got 6"+ of verti seperation on that front axle aswell. Enough to hold fine, although may wear joints faster.

Luke.

[Struth]

I have no dramas with the setup if it is a common method aimed at a goal, I still think the lower link points should be below the axle centre line more.

So the OP needs to explain is he having these difficultiies on road or off road. It doesn't look like a good on road setup to me.

Cheers

[Bagdad mafia]

Its has approx 160mm of vertical sepration at both ends,

Its a weekend toy not a daily driven car so i can put up with it not handling like it did before the swap but as near as good is better.

just ordered 3 new snake link arms with X-flex bushes so ill fit those and see how we go then, at the moment i have none adjustable 1"3/4 solid arms at 870mm long

[joeblow]

why do people do it that way. it would have to be one of the worst ways to do a front.......oh.....but i guess its easy!

Joeblow.
A 3 link + panhard is fine, Infact it is alot better than 'fine'. I would be willing to bet the two suspension types that win the most rock crawling competitions are 3-link + panhard and triangulated 4-links (not 5-link).

........derrrr....

Please tell me what suspension setup you think would work better with mechanical steering, Joeblow? A 5-link that binds up when articulated?

have you read what i said correctly?........"that way"........not as in how many links there are...

top arm should be central on the housing.

[RUFF]

top arm should be central on the housing.

Quick you better ring Jeep and tell them this

[Bagdad mafia]

Well aint this turned to S*#t....... please only input from helpfull persons as talking amongst yourselves dont get anywhere but in a s*&t fight.

Anyone got anything constructive to say !!!!!!!

[lukethedork]

have you read what i said correctly?........"that way"........not as in how many links there are...

top arm should be central on the housing.

I Apologize Joeblow. I did not read what you said as you intended it to be read.

I agree that it should be central on the housing. But it is often impossible to set up the suspension like that without making MAJOR changes to the vehicle.

Bagdad mafia.
Check all links for play.
If you are using any joints softer than polyurethane then change them out for hard joints.
Get your toe and castor set correctly.

The fact that the car will not self center after steering input makes me think that it is a castor problem.

Luke.

[v840]

The fact that the car will not self center after steering input makes me think that it is a castor problem.

X2

EDIT: Sorry, I posted bad info here. Edited in case someone reads my rubbish and gets the wrong impression. Good info below.





Serious question time, why should the upper link in a 3-link be centred? I've seen more than a few vehicles with an offset top link work great... Apologies if it's a retarded question but I'd really like to know!

[zookimal]

Serious question time, why should the upper link in a 3-link be centred? I've seen more than a few vehicles with an offset top link work great... Apologies if it's a retarded question but I'd really like to know!

Don't know that I've ever seen a centred upper link. Sump clearance normally makes it difficult anyway.

[95shorty]

The fact that the car will not self center after steering input makes me think that it is a castor problem.

X2

When you say -4deg measured off the kingpin bolts, is that leaning towards the rear of the vehicle or to the front?

If it's toward the rear then that is way too little, generally, castor should be positive, or angled towards the front of the vehicle.





Serious question time, why should the upper link in a 3-link be centred? I've seen more than a few vehicles with an offset top link work great... Apologies if it's a retarded question but I'd really like to know!

[WRXZook]

As above, positive castor is rearward inclination of the kingpin (at the top).

[80's_delirious]

As above, positive castor is rearward inclination of the kingpin (at the top).

yep, and 4 degrees positive caster should be enough to return steering to centre.

8mm toe in sounds like too much to me. 80series std spec is for 2mm toe in +or- 2mm (so anything from 0mm to 4mm)

Have you checked tierod ends are in good nick?

[v840]

My bad fellas. Had a brain snap.

[Bagdad mafia]

All rod ends are new.

Im running nissan Xflex bushes, Im awaiting my adjustabe top arm from snake so ill be able to adjust castor then, once thats done ill see how it drives then.

Thanks for the constructive advise.

[lukethedork]

All rod ends are new.

Im running nissan Xflex bushes, Im awaiting my adjustabe top arm from snake so ill be able to adjust castor then, once thats done ill see how it drives then.

Thanks for the constructive advise.

Some may disagree with me. But I would personally get rid of those soft X-Flex bushes and replace them with a hard joint (heims may be illegal for road use). I think that the soft bushes will be contributing to the bad road handling you have.

Luke.