Tuesday, October 21, 2014

Gee Whiz technologies for trucks and repair

Check out these technologies being considered for trucks in the near future.

Vehicle Service Pros

More than merely extensions of technologies presently in use  (like lane sensors, inter vehicle communication, or crash avoidance devices), these are potential game-changers that will likely be used in the near future. The last item, the force-sensing bolts and studs, are especially intriguing to me. They are probably talking about a piezoresistive or a nanoparticle-based strain gauge built into the fastener that will exactly measure the amount of stretch generated when the bolt is tightened. These could be used for cylinder head bolts or fasteners in other critical applications.

Saturday, October 11, 2014

One More Time on Mechanic Education

    Well, it is fall again, so the technical school programs are back in session. It is also time for me to once again harp on the sad state of mechanic recruitment and technical training. I won't repeat what I've already said on the subject, you can click on this link to check, if you like.

                                                                     My Ravings

    I recently came across something written by Sean Bennett on the subject. Sean has worked at truck dealerships, taught in truck mechanic training programs, and has written several textbooks on the subject.
    The link below is to a page from Bennett's blog, the first part written last year. The second part was written in 2008, but is still more than relevant today. As to female grade school teachers being the start of the problem, I will not touch that with a 200 foot long pole. I also will not comment on the public school social issue. I agree with what he says, but don't see it changing.

                                                                 seanbennett.org


    I do heartily endorse his ideas about college/vocational school training and the state of entry level techs today, as well as how things could be fixed. One point I have seen firsthand is the lack of computer savvy in many novice mechanics, even 20 somethings who must have grown up with technology. A couple I have worked with can't even do an effective internet search, let alone use a scanner. Granted, these were not products of technical school education, but Bennett says many graduates of programs also have very sparse computer skills. I find this disheartening and bodes ill for the future of the repair industry. I can't imagine how we will ever find the people to do the work after mechanics my age retire.



Tuesday, October 7, 2014

International Transtar Mode Door Stuck


    This post concerns International HPV trucks, (4300, 4400, Durastar, Transtar, etc.) A fleet customer came in with a Transtar tractor that wouldn’t change HVAC mode. The fan and temp controls worked however, so the first thing I looked at was the mode door motor. Both the temp door and the mode door controllers (motors) are on the left side of the HVAC airbox under the dash.
    The temp motor is on the scroll box containing the blower motor, and is easy to see. The mode motor is higher up and toward the firewall, kind of behind the wire harness for the fusebox. By switching the mode control and watching the motor’s output, I could see the motor was working. I could also see that the motor’s coupler that connects to the door was cracked and not turning the door. This isn’t uncommon, and usually means there is a problem with the doors. It is necessary to pull the scrollbox out and find the problem before putting a new motor on. To remove the scrollbox just remove the fuse cover, unplug the temp door motor, remove a few torx head screws and the scrollbox will slide out.
    Once the inside of the airbox was accessed, it became obvious what the problem was. Somehow the door gaskets on the edges of both mode doors had melted and the sticky residue had stuck the doors shut. Oddly enough the gasket on the temp door (in the scrollbox) was unaffected. The gaskets had the appearance, consistency, and stickiness of tar, and it took some work with a scraper and solvent to get it cleaned off the doors and the housing. I put a new motor on, then moved the mode from one setting to another to make sure the doors stayed free. The doors also didn’t seem to leak badly, so I wasn’t worried about letting the truck back in service without the seals.
    Soon after this repair I had an airbox apart in a 4300, which has the same HVAC system. The gaskets here looked OK, but when I squeezed one a little in my fingers found that it was also sticky and tarry. Obviously the seal material doesn't stand up to the environment it lives in. I have looked online and in Navistar’s tech bulletins, but haven’t seen any reference to the problem. Maybe the truck with the bad seals had overheated or something, but I will be on the lookout for this condition in the future.