Aligning a Gen_IV Toro, notes.

Having tried most everything with the front alignment, my 91 toro refused to run with the steering "in the middle". It would go with the wheel about 20 degrees out. The settings were as perfect as they can be. So the mechanic suggested swapping the two front tires across. And, it worked! Steering now centered, cars runs straight ahead if I let go of the steering wheel.

The mechanic mentioned that some tires are like this from new, it is not a fault, they just do. It is also importent that the "DOT" mark is fitted the same way out on all wheels as tires are not them same either way round on the rim, even when they look the same.

Also they are starting to use nitrogen to inflate tires as it would appear that nitrogen expands at about the same rate as rubber, meaning that the pressure remains nearly constant without regard to tire temperature. Didn't have it done but wondered what others know of this. Could be that somebody has surplus nitrogen and needs a new market ...

There is a TSB regarding the proper alignment of these cars. It involves new setting angles and possibly changing the motor mounts. It applies if the car has a left lead problem (tendency to pull left).

I have now cured a left lead problem that arose when I changed the tires to Pirelli P6000s. The GM TSB recommends a change to the camber settings at the front to Left: -0.5 +/- 0.5; Right: +0.5 +/- 0.5, all values in degrees. I had it set to exactly Right plus half a degree and Left minus half a degree. This has fixed the mild left lead I was experiencing.