On the 1932 AG Tourer I found the radius rods disconnected at the ball! Not a good idea! In the bits that came with the car were a pair of the brass bushes & a 3/8 BSF bolt & two nuts. Not a castellated nut & pin. This bolt goes through the bushes nicely & is the right length, but not through the eye of the rods!
A 5/16 bolt flies through the assembly.
Question: Is it 11/16", or a special bolt? or are both eyes damaged (unlikely). I think I will have to open the hole up in situ....I'm not taking it apart again!
It was not a simple replacement, one "cup" was very tight in the socket & the other arm was fitted so the arm end disappeared above the chassis! I loosened the nut at the axle end & applied penetrating fluid. Effort to the other end (big Stilson!)and something moved enough to fit the arms & new cups to the ball, but now I have to bolt it together.
The 5/16 will be a "doofer" now, but what should it be???
Are you sure Tony, I thought it should be 3/8" waisted in the centre to allow roll where it passes through the Ball. I have also just encountered a reproduction Ball with a 3/8" hole through it, I have several loose originals in my parts bins and more on chassis ranging from 1928 to 38 in age range, all appear to have 7/16" holes through the Ball. Obviously we want the bolt to be a snug fit where it passes through the Arm and Cup but with sufficient clearance in the Ball to allow for suspension roll. Can anyone tell us categorically if there was a change at any point in the bolt / hole size, perhaps something that coincided with the change from solid to sprung loaded centre bolt?? I have not personally seen evidence of this but just asking as a result of this thread.
Earlier cars had a 5/16" bolt with corresponding rods and cups, later ones 3/8" - the Service Journals or record cards may give the changeover date. It would appear that this car has acquired a mixture of parts and the practical answer would seem to be to open out the holes in the rods to 3/8" or get hold of a later pair, otherwise with a 5/16" bolt everything will be slopping about.
May 11, 2017 - 8:07AM
Re: Front axle Radius Rods
A short article/letter appeared in the Association Magazine about the changes to the design as described above - I cannot find it just now but it would have been around 2005-ish. From memory it was either written by Dvid Cochrane or Chris Gould, I think.
Purely for related interest, this is the drawing for the Prototypes that Stan drew up:
Thanks for that information.
I go along with Gadger's remarks. I think it likely that the arms are original & the balls later or repro. (one had a slight chamfer & the other an unbroken face where it entered the cup!)
I will grovel under the car with a sharp 3/8 drill....I'm not even thinking about taking the cups out...and clean everything.
I will use the 3/8 BSF bolt I have with a normal spring washer and lock nut it for good measure....the bolt is long enough.
It will interest me to see if this stops the front brakes coming on when applying steering lock....my original problem, before I found the radius arms to be disconnected!
sorry to confuse you Bob!
The bolt is a free fit in the cups and the ball, but the hole diameter in the arms will not accept the 3/8 bolt.
I think the o/s arm may have been "adjusted" for some reason....the arm was under some tension, but could be persuaded to fit onto the ball. the N/S lined up ok. Both now have vertical faces.
I note your comment about the tightness of the joint & may forgo a spring washer
Been getting rusted & broken steel screws out of the hood front rail today, so maybe get underneath tomorrow!