I have known about this issue for a while now, the pevious owner must have been in a minor front ender , when he had it repaired , they must have missed some damage, on the front passenger side, the wheel is sitting about 30mm back compared to the drivers side , I done some investigating and found that the bracket On the chassis end of the caster bar is actually bent out of shape like its been pushed back, it still drives fine and tire wear is minimal , but it is annoying the hell out of me now , is there any way at all that this can be fixed ? (1200 ute )
Any help appreciated , cheers

that's not unusual for any car of this age. Wheelbase each side is the first thing you measure when starting to setup suspension for a race car. In this case you can correct it with adjustable castor rods. Machine them down and extend the threaded section a few inches. refit with nuts either side of the bush to allow the castor to be adjusted.

Also renew the leaf spring front eye bushes (they will be worn), and check the alignment of the diff in the body.

How would I machine it down? A lathe? If I machine it down will this affect how the car steers at all? Will it be noticeable ?

I have been meaning to do so with the eye bushes but I am replacing the standard ute leafs with 1200 sedan leaf springs, where can I get new bushes from?
Cheers

yes, in a lathe.
the leaf eye bushes are available from any suspension specialist, most proper auto parts stores, or on ebay

Good luck with that mod guys

http://datsun1200.com/modules/newbb/v ... e=&topic_id=51188&forum=1

roll your eyes all you want. Mine lasted from roughly 1998-2004 as an everyday street car for about a couple of years that did the odd Datsun club day at Lakeside, then a street/track car for a couple more year and eventually a dedicated race car for the last 2 years. In that time they survived a crash at Mt Cotton Hillclimb that tore a castor rod bracket off the chassis, and another crash in a classic road rally sideways into a kerb that sent the car airborne, broke a wheelbearing race and bent the chassis. They were pulled pretty hard to about 7 deg castor, ran grippy semi slicks, and had a big heavy L18 in the car. In that time it would have easily done over 50,000km and countless events. I wouldn't hesitate to do it again. It's a pretty common modification for race cars. The modification done properly causes no more stress risers than is present in the standard unmodified part.

OK thats good. Your luck is holding then.

Some facts. A threaded rod subject to high cyclic tensile loads is a fundamental suspension design compromise which needs all the help it can get to survive. This design shortcut is not now used in vehicles anywhere that I've seen in a long time.

Cutting additional thread on a lathe (or worse still with a die nut) does not improve its durability. Its not a matter of if it will fail - just when it will fail. The time to failure is now dependant on the skill of your machinist and the quality of his equipment.
Compromising the compromised design further and the cycles to failure reduce even more.

Feel free to disagree. I'm really only concerned someone will hurt themselves or worse still hurt someone else.
In the meantime this may be worth reading. http://www.resnapshot.com/MD1298.htm

I had the same problem on my ute,i passed out going through a round about due to type 2 diabeties which was un diagnosed at the time.I hit the round about with the front right wheel with enough force to tear the caster bar mount off the chassie which pushed the wheel back,maybe this has happened to your ute or similar.I then sold it pretty much straight away telling the new owner off the problem before he bought it,i was in contact with the new owner about a month later and he had fixed it without any major dramas.Maybe made easier because he was a qualified panel better and spray painter.

theory is all well and good, but being able to actually read it and come to an informed opinion is another matter.
That article even says a rolled thread makes the material stronger.
But if you're that worried, use the Datsun competition method - no thread extension, and radius the shoulder.

Like Benny, I too have had a radius rod break and I know of another car that had the same issue ( at speed)
Harry, I cant comment on what you are saying other than I really respect what you write but this time I can not emphasise enough DO NOT DO IT. Get the vehicle to a proper chassis repair shop and get it fixed properly.
As far as the race car went my engineer took one look at what was happening and could see that the angles that the radius rods were at were all wrong.
The solution was to fizz the mounts off the front chassis rails and reposition new ones as well as fitting a rod end to the radius rod.
Now the whole front end moves freely and I am wrapt with the way it handles.
Cheers
Dave