505 GR radius arms

zac505

zac505

Member
Fellow Frogger
Joined
Mar 1, 2004
Messages
226
Location
Coffs Harbour, NSW, Australia
Oh wise ones!...

I've just removed my radius arms awaiting new bushes, which are in the mail thanks to Kermit's contact - all hail Kermit.
Are the two arms identical i.e. interchangeable? My car's obviously had a few botch jobs done on it in the past, and one of the cup shaped washers was in backwards (according to my Haynes), and the bushes were chewed from over tightening (?). My concern is that maybe somebody lazy has put an offside arm nearside or vice-versa. They look as though it should be OK, but I'm unsure. Anybody...
 
There's a difference between 504 and 505 arms, but they're so close that I've actually got them mixed up once!

But they are interchangeable from one side to the other... just check that they are indeed exactly the same.
 
i think it was peujohn that put the shorter 504 ones in a car not so long ago and it gave the car positive castor

now this is something i'll be definately be looking at in the near future as i plan on double sway baring the 604 and dropping it a little

time to get a 604 down and less boaty :D
 
Castor?

pugrambo said:
i think it was peujohn that put the shorter 504 ones in a car not so long ago and it gave the car positive castor

now this is something i'll be definately be looking at in the near future as i plan on double sway baring the 604 and dropping it a little

time to get a 604 down and less boaty :D
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Thanks again guys. Would you mind explaining the concept of castor to me in 50 words or less? Once again I'm a bit in the dark. I have had camber and toe-in explained to me, but haven't had the castor rave from anybody yet...cheers, zac

P.S. - pugrambo, was the 604's body penned by the same design house as that Ferrari V6ed 2 door Fiat of the early-mid 70's?
 
zac505 said:
Thanks again guys. Would you mind explaining the concept of castor to me in 50 words or less? Once again I'm a bit in the dark. I have had camber and toe-in explained to me, but haven't had the castor rave from anybody yet...cheers, zac

P.S. - pugrambo, was the 604's body penned by the same design house as that Ferrari V6ed 2 door Fiat of the early-mid 70's?
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yes the 604 was penned by pininfarina hance the similarities

it also sits on basically a 504 floor plan
 
Just wondering, how much are the radius arms bushes going to set you back? I've got to replace mine along with a few other steering bushes, that's all, including the steering rack boots.

Btw I would have assumed that both radius arms are interchangeable (ie left and right), but would have labelled them just incase.

Do you think you could email me the contact details of this person your getting parts off?

sajica at iprimus.com.au

please the remove spaces and put in @ instead of at :)
 
zac505 said:
Thanks again guys. Would you mind explaining the concept of castor to me in 50 words or less? Once again I'm a bit in the dark. I have had camber and toe-in explained to me, but haven't had the castor rave from anybody yet...cheers, zac

P.S. - pugrambo, was the 604's body penned by the same design house as that Ferrari V6ed 2 door Fiat of the early-mid 70's?
Click to expand...



Think of a bicycle with front forks vertical, this would have zero castor, In the normal position this gives positive castor and if they sloped backwards it would be negative.
Sean, the different arms would have increased the original positive castor.

Out of interest Hubert Opperman's speed record bicycle had the forks reversed so that he could get closer to the vehicle he was following (at over 160 km/h Ias I remember)!!!!! A brave man indeed, and a huge front chain ring!

Graham Wallis
 
Just to add... Caster aids in self-centering the steering.

The weight of the car settles the steering in the centre because that's where it sits the lowest with the suspension set that way. As you turn the steering, the shape of the tyres tends to lift the weight of the car.

It also promotes the feel you need to help you know what the car's doing...
 
Radius arm front bushes

Thanks again all. Got the castor thing now.

While on the radius arm thread, any tips on squeezing the new front bushes in? They're proving a bit awkward. Please let there be a simple trick.
 
zac505 said:
Thanks again all. Got the castor thing now.

While on the radius arm thread, any tips on squeezing the new front bushes in? They're proving a bit awkward. Please let there be a simple trick.
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smear a little brake fluid on them

and no it won't eat the rubber it actually protects it and they slip in easier
 
zac505 said:
Thanks again all. Got the castor thing now.

While on the radius arm thread, any tips on squeezing the new front bushes in? They're proving a bit awkward. Please let there be a simple trick.
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A big vise and suitable bolts/spacers etc.

Graham Wallis
 
zac505 said:
While on the radius arm thread, any tips on squeezing the new front bushes in? They're proving a bit awkward. Please let there be a simple trick.
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Put them in the freezer. They'll contract and go in easier. This is what I've been told anyway... I believe the mechanic who modified the front end on my car did this.

My 504 has early 505 lower control (gives about 1.5 degrees negative camber) and the original shorter caster bars for about 4 degrees positive caster. Having the shorter bars pulls the control arms forward a little... as a result the bushes aren't all lined up perfectly, but this hasn't been a problem so far. The car has sharper turn in and much less understeer, especially in tight corners such as roundabouts. Also, from direct front on, the car looks TUFF. ;)

John
 
Originally posted by peujohn
My 504 has early 505 lower control (gives about 1.5 degrees negative camber) and the original shorter caster bars for about 4 degrees positive caster. Having the shorter bars pulls the control arms forward a little... as a result the bushes aren't all lined up perfectly, but this hasn't been a problem so far. The car has sharper turn in and much less understeer, especially in tight corners such as roundabouts. Also, from direct front on, the car looks TUFF
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If that works it might just be a good plan... but does this mean that Graham is wrong about the lower control arm lengths?

Oh, yeah, and who cares how it looks... as long as it works?
 
Ray Bell said:
If that works it might just be a good plan... but does this mean that Graham is wrong about the lower control arm lengths?

Ray,
As I said the 505/604 arms are 20mm longer than the 504 ones thus giving you negative camber when fitted to a 504.
The reason the early 505s have postive camber is that the top stut mountings are further apart.

Graham
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zac505 said:
Thanks again guys. I'll try all of the above and report back...zac
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Freezing can be handy for the steel sleeved bushes (such as the inner lower control arm bushes, but won't do anything for the front radius rod bushes which vasolene and a good vise or press are the answers here.

Graham Wallis
 
Still trying...

GRAHAM WALLIS said:
Freezing can be handy for the steel sleeved bushes (such as the inner lower control arm bushes, but won't do anything for the front radius rod bushes which vasolene and a good vise or press are the answers here.

Graham Wallis
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The two smaller bushes at the rear of each radius arm just slipped into place, but even after freezing and greasing the front bushes, and cranking them almost all the way into place using a long bolt and some washers, I'm still having trouble fully seating them. I don't think the freezing helped really, thanks anyhow John. I managed to get the large cupped shaped washer and the nut on, and hoped that simply tightening the nut would push the bushes into place, but I'm still left with a 3-4mm gap. I obviously do need a vice, but would they seat if I moved the car forward (please tell me if this is a totally naff idea, and if I should stop this enthusiaistic amatuerism, get the right tools for the job or seek professional help).
I was also wondering about the orientation of the cupped shaped washers at the front of the radius arms. When I took mine off they were cup facing forward, but given the shape of the bush behind I was curious as to whether they might go the other way around...zac
 
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