[DeTomaso] Increasing Caster

JDeRyke at aol.com JDeRyke at aol.com
Fri Apr 29 14:42:12 EDT 2011


In a message dated 4/29/11 9:10:43 AM, kenn_green at yahoo.com writes:

> I think this has been discussed, but can anyone estimate the total caster 
> that can be obtained by offset bushings and milling one side of the upper 
> ball joint?
> 
Panteras will vary a bit from car to car in how much caster they have, and 
caster- the backward inclination angle of the front upright- is usually 
measured in a rather imprecise way at home by using a bubble level caster gauge. 
Pro laser level gauges may show different amounts. 
On our '72, the max stock amount (bubble gauge) was -2.1 degrees with all 
the shims in front of the ball joint carrier.
By using only offset upper bushings, one doubles -caster to about -4.2 
degrees including the above. This seems to be enough to nicely stabilize the 
steering up to a tested 150 mph. 
By ALSO using offset bushings set the opposite way in the LOWER a-arm, 
cumulative negative caster is increased to near -6 degrees
By milling around 0.080" from one side of the ball joint carrier and not 
falling thru the side into the grease chamber, one gains an additional -1 
degree for close to -7 degrees cumulative. Some risk-takers cut a little more. 
This is not a hacksaw-and-file job.
So far, all the changes are reversible in a few minutes. Extra home-made 
shims can be used to readjust all the way back to stock. Wheel toe-in WILL be 
affected when changing caster at all, as will tire clearance to the 
right-side wiper motor shield and possibly the brake hose routings.
I personally find our car to be difficult to steer in traffic with more 
than -4-1/2 degrees. Over -4-1/2 recommended only for power steering 
conversions and really high speed use. FWIW- J DeRyke



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