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Fitting longer 'arms' to steering rack?
Northy - 19/1/03 at 01:45 PM

Does anyone know if it's possible to swop the 'arms' (by this I mean the bits the ball joints screw onto) with longer ones?

Are they replaceable? How? Would Sierra ones fit? Are Sierra ones longer? If I can't change they I'll have to make some extensions

Cheers

Viper - 19/1/03 at 02:07 PM

I know why you are asking this. don't know the awnser though, but i am assuming you have your front wishbones and uprights fitted is the front track the same as the rear? i ask because i don't understand why tiger chose to extend an escort rack..

Ian Pearson - 19/1/03 at 05:18 PM

I know that MK extend their track rods. Not sure what lenght the extensions are though.

Jon Ison - 19/1/03 at 07:28 PM

IMO only and others may not agree, but extending arms is a good thing as it helps to get rid of any bump steer you may have, i allways used the shortest rack and longest arms i could when building autograss cars, a longer arm makes much less angle when the susspension moves making for less bump steer,

the arms on the isonblade r extended.

Northy - 19/1/03 at 07:53 PM

Viper,

No, the front track isn't as wide as the back.

Ian,

How do MK extend their racks?

Jon,

How do you extend yours? (Oh er missus!)

Ian Pearson - 19/1/03 at 08:59 PM

Graham,

My escort rack was shortened to help reduce bumpsteer, and the arms where extended by cutting the arm and tig welding some thick wall seamless tubing to make up the necessary length. Instant SVA and MOT falure!

MK's are extended with a threaded adapter ( I think!) but I don't know if they make custom extensions or not. I need to find out myself!

Regards, Ian.

Jon Ison - 19/1/03 at 10:36 PM

How is welding an instant failure ? you see lots of fabricated / weld'd uprights, steering arms,

mine are sleave'd then tig weld'd, better take mine back for the relevent fail certificates.... or was i just lucky...

most people have there track control arms coverd for the sva and i've not heard of any testers looking under there....

locodude - 19/1/03 at 11:04 PM

MK shorten the sierra rack and then use threaded adaptors. This moves the joint on the rack into the same plane as the wishbones virtually eliminating bump steer. I think they are only available for the sierra rod ends tho'. I'll ask in the morning.

Rorty - 20/1/03 at 03:09 AM

Jon Ison:

quote:

....extending arms is a good thing as it helps to get rid of any bump steer you may have, i allways used the shortest rack and longest arms i could when building autograss cars, a longer arm makes much less angle when the susspension moves making for less bump steer

In theory that's correct, a longer track rod will travel through a lesser arc, but that's not the whole story.
With end load racks (centre load racks are another kettle of fish), the ball joints on the ends of the rack, must lie in a predetermined location, and after that, lengthening the track rods will only increase toe-out.
Most track cars with virtually no suspension movement, position the rack so its ball joints, when viewed from the front, are lined up with the inner pivots of either the top or bottom wishbones. The track rods then run parallel with the wishbone to the steering arm.
On road cars such as the Locost, the rack's ball joints are best situated by determining the relativity of the trackrod end's centre on a line drawn between the centres of the top and bottom upright ball joints, and transferring the measurement, relatively, to a line drawn between the inner top and bottom wishbone pivots.
Both of these rack location methods will only provide accuracy as long as the steering is in the straight ahead position. Once the steering wheel is turned, and the rack moved, the geometry is instantly messed up with one or both wheels.
Only minor fettling of the rack's fore/aft and up/down positioning, can help to eradicate bump steer.
It's probably not a bad idea to quickly check for bump steer before your car goes on the road. Even a very small amount of deviation of the wheels can be unsettling. It's quite a straight forward process to reposition the rack correctly.

Jon Ison - 20/1/03 at 07:09 AM

I'm afraid thats all to much for me....

bit like my insurance policy

philgregson - 20/1/03 at 12:29 PM

Can someone confirm whether lengthening steering arms by sleeving really is likley to cause an SVA fail as I am widening my track by 4" and was planning on extending escort arms.

This does seem perverse to me if true as the rest of the suspension will have been welded by me.

Cheers

Phil

Jon Ison - 20/1/03 at 02:07 PM

To put your mind at rest and get it from the horse's gob ring the SVA center your gonna use....

the number for nottingham is 01159 382591, hope this helps...

philgregson - 21/1/03 at 10:40 AM

Thanks, I'll give that a go.

Are they generally happy to spend all day answering stupid questions from LOCOST builders?

Cheers

Phil.

Jon Ison - 21/1/03 at 02:49 PM

yes

Ian Pearson - 21/1/03 at 06:19 PM

Hey Jon,

ISTR you telling me that your build was SVA excempt?

I have spoken to the SVA at Swansea, and was told that it was a definite failure. Speaking to an MOT Inspector, I was told that welding [had been acceptable but that regs had changed. I presume that if your build is SVA excempt and aged prior to the regs, then you'll have no problems. Having modified my arms, the last thing I want to do is spend more dosh. However, I don't want to put my car in for test with a known failure point in the hope that the man from the ministry chooses not to look under the covers.

jollygreengiant - 21/1/03 at 07:43 PM

quote:
Originally posted by Ian Pearson
Graham,

My escort rack was shortened to help reduce bumpsteer, and the arms where extended by cutting the arm and tig welding some thick wall seamless tubing to make up the necessary length. Instant SVA and MOT falure!

Regards, Ian.



Mot Regulations state :-
ANY suspension or steering, component that has been subjected to excessive (in the opinion of the examiner) heat is grounds for failure.

To whit example. you take your cavalier in for ---- TRACKING. It is out, they slacken the lock nuts but the adjuster will not move.
Correct method (takes time eats into profit) remove arm from rack and strut arm, fit into vice (all this should be done only after advising customer of possibilities) & attempt to release 1 component off of the other 2, then split last two, clean, grease & reassemble. Usually something breaks be it a lock bolt or an adjuster bar. Customer would then pay for new items.

USUAL METHOD employed by some 'specialists', apply hot spanner & adjust. (this method leaves evidence in the form of heat dicolouration and melted metal. And if spotted by the tester is grounds for failure because it could leave the metal in a weakened state). also the heat could transmit to the ball joint leaving the plastic bush melted & or distorted. If customer spots problem or it fails MOT then garage is liable.

Go on admit it how many times have you seen it done during a tracking opperation & thought nothing of it.

Hope this answers your queery.


Enjoy.



Yaaaahoooooooo Back to work tomorow.
Oooohhhhh Gawd A45!

johnston - 21/1/03 at 08:30 PM

have to admit that i've never seen anyone heatin a track rod for any reason

wd40, a big shifter and tappin stick works everytime for me

johnston - 21/1/03 at 08:33 PM

have to admit that i've never seen anyone heatin a track rod for any reason

wd40, a big shifter and tappin stick works everytime for me

Jon Ison - 21/1/03 at 08:36 PM

i did start my origional post "IMO" and still stick by it, do what you have to, i'm happy to drive balls out with my weld'd arms, any MK owners out there gonna ditch there welded rear uprights ? thought not, was looking at them again today whilst i was over there, well made solid looking things with proper welds, now if they coverd in bird doo doo may be another story.....

Jon Ison - 21/1/03 at 08:42 PM

another fly in the thingy to consider...


does this mean all our trailing arms/panard rods, wishbones are a failure ?there all susspension components, there is a line some where, but where is it ?

there thats me done on the subject...

Rorty - 22/1/03 at 04:15 AM

This is probably the biggest can of worms ever (in terms of authorities/safety).
I presume the original idea of not applying heat to a steering arm or track/tie rod, was so as to not interfere with any heat treatment applied by the manufacturer. They probably hadn't taken into consideration that the whole kit and kaboodle may end up being home-built, which in turn means welding, and no heat treatment!
Having been out of the UK for around 11 years, but reading between the lines, I think the days of home-built cars are numbered. You might be best advised to not ask too many questions, for fear of bringing down the hatch sooner.
I think having JollyGG as a virtual horse's mouth on this forum to act as a sound board is the correct approach. Sorry JollyGG, no offence meant whatsoever. (I do have to be careful, as I've had my sense of humour questioned here recently!)

jollygreengiant - 22/1/03 at 06:25 AM

No probs M8, I tend to regard myself at times as the other end anyway, cos nobodys perfect, Besides as far as (IMO) MOT'in goes the testers are in no-mans land between the customers (surely thats not failable or its always passed before), the company they work for (fail more cars), and the Vehicle Inspectorate (your to hard or your to lenient) anyway. EVERY TEST is meant to be 100% right ALWAYS. Most of the time you can drive a lorry through some of the vaguities of the regulations and operational procedures as well.



Enjoy.

Northy - 22/1/03 at 08:00 AM

So then guys,

How do I extend the arms

a) safely?

b) sva friendly?

Comments

Thanks

jollygreengiant - 22/1/03 at 08:07 AM

Easiest method that I can think off, Get someone to machine out of solid bar some extensions to go between rack end & track rod end. Fit lock nut, screw down fully home & lock of with locknut. Then treat track rod end as per normal.





Enjoy.