The concept of 'Scrub Radius' described in the linked article was driven home to me a few years ago when a customer brought me his new-to-him Dodge 3/4 ton pickup complaining of a loss of power steering at very slow speeds. This car was impossible to parallel park as the steering wheel couldn't be turned by human hands when standing at idle. Having seen plenty of failed power steering pumps that was my first (faulty) diagnosis, but a replacement had no effect. After a couple more failed attempts at repair (on my dime - that's my policy) I visited some friends at the Dodge dealership and discussed the problem. No one had any ideas beyond what I had tried and had never seen the same fault. I mention this because I eventually discovered every 3/4T Dodge P/U of similar years suffered from the same "failure". They had so much offset in the scrub radius that even with power steering the tires couldn't be turned at a stop - UNLESS the driver released the brakes! This allowed the tires to roll forward and backward visibly and turn easily. What did I do with this hard won knowledge? Not a thing, who the heck parallel parks a 3/4 T PU? Hopefully it may help someone reading this. Joe
Damn... I love the way you tell this, and kudos on your policy, that's hard to find honest mechanic policy right there! But, I also laugh, as you say, what did I do with the knowledge? Nothing. HA! THanks!
Many of the "Bro Dozer" lifted trucks like the one that got stuck on its hitch have very deep dish wheels. They must get a lot of steering effect from hitting bumps or braking.
The concept of 'Scrub Radius' described in the linked article was driven home to me a few years ago when a customer brought me his new-to-him Dodge 3/4 ton pickup complaining of a loss of power steering at very slow speeds. This car was impossible to parallel park as the steering wheel couldn't be turned by human hands when standing at idle. Having seen plenty of failed power steering pumps that was my first (faulty) diagnosis, but a replacement had no effect. After a couple more failed attempts at repair (on my dime - that's my policy) I visited some friends at the Dodge dealership and discussed the problem. No one had any ideas beyond what I had tried and had never seen the same fault. I mention this because I eventually discovered every 3/4T Dodge P/U of similar years suffered from the same "failure". They had so much offset in the scrub radius that even with power steering the tires couldn't be turned at a stop - UNLESS the driver released the brakes! This allowed the tires to roll forward and backward visibly and turn easily.
ReplyDeleteWhat did I do with this hard won knowledge? Not a thing, who the heck parallel parks a 3/4 T PU? Hopefully it may help someone reading this.
Joe
Damn... I love the way you tell this, and kudos on your policy, that's hard to find honest mechanic policy right there! But, I also laugh, as you say, what did I do with the knowledge? Nothing. HA!
DeleteTHanks!
Many of the "Bro Dozer" lifted trucks like the one that got stuck on its hitch have very deep dish wheels. They must get a lot of steering effect from hitting bumps or braking.
ReplyDelete