Auto Service World
News   October 13, 2010   by CARS Magazine

Fire in the Hole…

I hate torches. Oxy acetylene, acetylene-air, butane, propane - if it shoots a flame, I don't like working with it. I was reminded of this during a recent video shoot for ssgm.com where I replaced steering components on a Ford light truck.


I hate torches. Oxy acetylene, acetylene-air, butane, propane – if it shoots a flame, I don’t like working with it. I was reminded of this during a recent video shoot for ssgm.com where I replaced steering components on a Ford light truck.

Like many hard-working trucks, this one had seen its share of salt, dirt and moisture, so it was a dirty, knuckle-bashing mess. The pickle fork and impact gun is great when you’re throwing the old stuff away anyway, but the issue that has bothered me for years is the Pitman arm. They’re a dying species as rack-and-pinion moves into sport utilities; but there are enough around to add a few more scorch marks on my hands. That’s because they have two major failings: they’re splined to a rusted, super close-tolerance steering box sector shaft and they often have a joint attached to the other end. That joint wears just like the tie rod ends and idler arm, but why does it have to be on the Pitman arm?

On this Ford, the joint could just as easily been on the centre link, making the service as fast and easy as the tie rod ends. By placing the joint on the Pitman arm, I was forced to use my Pitman arm puller, of course, which refused to budge the arm despite major torque from yours truly, which left heat. Expanding stuck parts to get them apart is an everyday practice in most shops; but a simple design change would make it unnecessary here.

Look at the area: a heavy forging that needs lots of heat to expand; lots of flammable grease in the immediate area; an oil seal just above the part you’re heating; and finally, one hand occupied holding the torch head while you try to prevent the puller from flying into hyperspace when the arm lets go. Flame heat releasing stuck fasteners is a safety menace if you ask me since, unlike welding, you can’t control the immediate environment. Your eyes don’t like it either and there’s nothing as painful as slipping that blue cone across the back of your hand. The “hot foot” as the spark goes down the boot however, is generally amusing when it happens to someone else. Your vocabulary reduces to three or four words which take full advantage of the “no customers in the shop” rule. There are induction heaters, but they’re expensive and you can’t braze or weld with them, so we’re stuck with the tanks.

It would help if chassis designers would put the joints that wear on parts away from forgings that belong on a D9 Cat. I’ve talked to many an automotive engineer and there’s always an excuse: “It’s cheaper that way.” “It’s no better the other way.” We have to control cost;” and my favourite, “We tested it with the Service/Parts guys and they said it’s fine.” Maybe dip the prototype in a salt bath for six months then try it again.

This Rant may be spitting in the wind, but frontend service needs speed to be profitable, and stuffing shop rags into a burning chassis isn’t the route to efficiency. Many shops tack a torch charge on the work order, but maybe there should be a PITA fee for poorly designed, poorly maintained vehicles.

I was so mad I probably could have heated the Pitman arm just by staring at it, but it came off without damage in the end. But rack-and-pinion technology never looked so good.


Print this page

Related


Have your say:

Your email address will not be published.

*