convoyduel

For the 1977 RS700L that was used for many of the shots, the dash is mostly he same as Tren't pics, except that there was an AM radio installed vertically at the far right of the dash. The interior is all black with a black dash. The gauge panels are fake wood and the steering wheel, shift knob and tilt wheel knob are all white. The HVAC unit below the dash has 3 circular vents, common to late RS models and early Superliners. The seats are low-back black vinyl, with air ride only on the driver's seat. The CB was mounted overhead, center of cab. There is no overhead console in the cab.

We have a factory installed Jacobs-brand Jake Brake on our '90 CH613 with a E6-350, and it's absolutely useless. It barely even slows the truck down while bobtailing. The local dealer said that's probably about all it was good for when it was new. Dan Bruno www.stlouisdumptrucks.com

Basically, to add to what RS was saying, all cars and light duty pick-ups have synchronizers in the transmission that activate when you push the clutch pedal. The synchronizers align the speed of the gears in the transmission to the speed of the engine and the driveshaft. This was primarily done so that absolute morons with no mechanical aptitude can put on make-up or yap on the cell phone while bearing only a minimal responsibility for the 3000 or 4000 pound piece of machinery they are operating. On heavy trucks, there are no synchronizers, so it is up to the driver to match the RPM's and gear selection with the driveshaft speed. As soon as the driver runs through a gear, the shift to neutral begins a process where the driveshaft speed will increase or decrease with the speed of the vehicle (depending if it is on flat ground, or up/downhill). Also, the gears in the transmission fall out of synch as part of them turn with the engine rpm input speed and others turn with the driveshaft output speed. To get into the next gear, the driver has to select a gear that can bring the two speeds back into synch, and make the final adjustment to complete the match using the engine RPM's. Many drivers will float gears, shifting progressively up or down without using the clutch. This process is accomplished by moving the gear selector to the neutral position at the split second that the drivetrain "slacks" as the driver eases up on the accelerator. As the next gear is selected, the driver brings the engine RPM's to a speed that puts the revolutions of the gears on the input side of the transmission to the speed of the revolutions of the output side of the transmission from the driveshaft. As everything falls into synch, the gear level is eased into the next gear. Think of a farm tractor pulling a wagon hitched together by a pin. When the tractor is pulling, there is tension on the pin. If the tractor slows, the wagon drawbar will ease forward and compress against the pin, but there is a precise moment when the pin is being neither pushed nor pulled. At that exact moment, the pin can be pulled, much like the gear selector when floating gears. Double clutching is often used when a transmission is tight or less forgiving for floating gears. By pushing the clutch when leaving a gear, it eases the tension in the driveline, but it releases the link between engine RPM's and the gears on the input side of the transmission. Releasing the clutch puts power back to the front side of the transmission to keep turning the input gears. By applying the clutch a second time as you select the next gear, it allows the drivetrain some slack again to make matching the next gear a bit easier. Mack transmissions are notoriously tight and not as conducive to floating gears as other transmissions such as Eaton Fullers or Rockwells.

I picked 2 of the Rawhide's up at Wal-Mart Thursday for $4.97 apiece. Nice toys for 5 bucks. The e-bay one's were going for more than $25. Buyer beware on e-bay.

When a wrecker tows a tractor trailer, the wrecker's trailer air lines are only used if the truck being towed has a trailer. In that case, the wrecker's air lines are run back to the trailer. You never hook the wrecker's air lines to a towed tractor's air system. The treadle valve on a tractor is the gateway for air applied to the service brakes. To access the service brakes, you would have to split off from the lines from the treadle to the brakes. Tractors with dual air brake systems would require an even more elaborate setup. It's somewhat of a moot point, as a towed tractor should only have 1 axle on the ground anyway. An empty tractor in-tow will be easily handled by the wrecker's brakes. If you also have a trailer, the wrecker and trailer's brakes will do what you need.

Saw a Mack Magnum Superliner at the dealer here in St. Louis today. The truck is out of North Carolina, but the driveshaft was on the 5th wheel, so I guess it was towed. The truck is showing its wear on the outside, but the red interior was immaculate, including the original seats. If I get back by there tomorrow, I'll take a picture or two. Did all of the Magnums have an aluminum frame? The three I've seen to date have. If the E9 threw craps, I'd bet you could get the truck cheap! Dan Bruno www.stlouisdumptrucks.com

You're most likely going to have to make one yourself or pay someone to do it for you. What are you calling the wiring harness? There are a lot of simpler sub-assemblies to various parts of the truck, and then there's the interior wiring. There's not a likely source for an exact wiring harness for your truck. Dan Bruno www.stlouisdumptrucks.com

Barry, The final run of RD's were RD Legend models and were built in Oct, Nov and Dec. 2003 as 2004 models. I should have bought one, but passed on the chance. We bought '04 CH613's instead. The local dealer told me last week that the DM and RB's were no longer available for order once the Granite Axle Back was rolled out. Dan Bruno www.stlouisdumptrucks.com

Ouch. I thought that was the best R model short hood offered. A friend of mine said that he always felt that new RD hood was more reminiscent of something you would have seen from Brockway in later years. I see his point. Our 2002 RD was a pretty good truck, but suffered from Mack's notorious electronic malfunction engine issues so common of late production years. As a side note, when ordering cab parts for our older RS700L's, we typically just give them the RD690's VIN. Saves a lot of trouble and aggravation at the parts counter. Dan

Trent, Go to my main website www.stlouisdumptrucks.com and use the link to the Convoy page. There's an interim page that shows the wrecked truck pics. The truck that was turned into a mixer for Bruhn was the '73 with the NTC Cummins. The biggest giveaway on the transfer dump is the lack of mounting holes for the air deflector, the lack of any kind of cut out for the walk-through sleeper and the fact that it is a 1978 model when the movie trucks were acquired in March 1977 for filming. Two of the five trucks did not have cut outs for the sleeper. One was the shelled out pre-73 used for the bridge dive. The other was an RSK700L Glider kit used for some cab close-ups. My biggest beef with statements like his is that you don't make claims like that without some sort of proof. As for the Bruhn mixer truck, it still exists today in its wrecked form. I've thought of buying it just to say I have it, but the truck is literally nothing more than scrap metal. Wanna roadtrip? Dan

The truck is a bit rough. I've seen it up close in person and it is not one of the trucks used in Convoy, though. The truck's been popping up for sale for over 2 years on Truck Trader.

Hey kids. I've spent a few hours on the site from time to time and finally registered. I know some of you, but look forward to meeting more of you as time allows. We own the surviving Peterbilt and tanker from Duel and have the replica of the RS700L used in Convoy. If you're ever in St. Louis, stop in and say hello. Dan Bruno www.stlouisdumptrucks.com