Rob

I will try to find the high gear position this week. I've never been around anything other than a Mack two stick, and an RT-910 that I converted to an RTO when rebuilding. I haven't driven the truck yet as it has an oil leak from the cam/rocker box due to a 5/16" piece of gasket material being "blown out" and it really leaks quite well. I want to fix that and parts should arrive today or tomorrow. Thanks for the help!! Rob

Hi there, tonight I've looked, scraped, washed, bashed head etc. looking to identify the transmission in my truck. I do know it is a 13 speed Eaton/Fuller, but I cannot find a tag anyplace. There is a flat spot in the case (right side of case) with a couple of holes that look as if there was a metal tag retained with drive screws, but it is empty, and there are no remnants of any fasteners remaining. The rear carriers have 4.17 stamped into them for a ratio, however when the truck was driven up to my shop, the driver stated that it had a lot more to go (road speed) than 4.17 gears would deliver. This tells me the transmission is either an overdrive version (RTO12513?), or the rears have been changed out. I have not driven the truck myself off of my property so I can't give first hand knowlege. I do know that at 60 mph he was right on my rear bumper and later investigation revealed the truck is "turned down" to run only 1800 rpm against the governor via my non contact tachometer, (it is accurate). Without physically pulling the transmission and counting the output shaft revs in comparison to the input, is there any way to discern which transmission is installed? I could break the driveline apart and use my tach to compare the above mentioned revolutions, but that is quite a bit of work. Thanks, Rob

Never being a "trucker" myself, but growing up around B model Macks well into the 70's has me a bit biased. I too have visited some of the other boards, (and used to participate), but do not frequent them often. Don't get me wrong, there are many smart persons there, I just don't care for the "bullshit" as I'm not one of the boys. If time is on your side you will get straight answers to questions without the unneeded comments no matter what the brand of the truck here. I think Barry does a "hell of a job" on this website. I also spread the word about this site to anyone interested in old trucks I run across. Rob

Looks nice Barry. What are the chances of seeing some 36" mudflaps, (such as installed onto the model) being produced? They sure would look good on my A-40 dump truck. Thanks, Rob

Hi there, I'm looking for a factory Caterpillar service manual for a 1693TA engine. Mine has an oil leak between the spacer plate and head, (I can see a portion of the gasket missing) and I would like to have a good data source before breaking into it. Engine runs great, but is a little low on oil pressure; at idle only runs about 20psi when hot, but goes right up to 60 plus above idle. I am planning to at least roll lower bearings in while it is out of the chassis. I also can't figger out this "brakesaver" thing without a diagram. Thanks for any help in advance!! Rob

You can also use a remote tank type heater that functions as a pump (due to temperature differential) to circulate the water through the cooling system. Kats, or Zero Start brand both market them and they are easy to install by tapping into the water lines. I've used them for over 20 years without problems. Rob

Barry, I will look through my notes to reference the point of contact I used. "She" was very friendly, knowlegable of my inquiry, and interested in helping. There was no way she could get past the minimum order thing due to costs for setup as the original patterns no longer existed. Rob

Doug. they are PVC material and not rubber. A lot of folks around here refer to them both ways so I just stayed with the convention at hand. Rob

Hey Barry; They were the white heavy ribbed (on rear) rubber, brown & black dog, Mack Trucks in red, standing on a green oval. Five colors in total, hence the name "Five color Mack flaps". The image was also "burned into" the face of the flaps. Both dogs were opposing, or looking at each other. Keep us posted as I'll take four sets. Rob

Hi Barry, I spoke with Koenetta Plastics on reproducing the original 5 color Mack flaps from the seventies period and they were willing to do it at a minimum of 2500 sets, (1250 right flaps, 1250 left flaps). They were the original vendor to Mack Trucks during their production run. It was not costly per piece, but that much inventory was a bit much for a single user. Rob

Hi Rod, great to hear the news of your recent "arrivals". I have never tried to pull the engines and transmissions together. The way Mack mounts their drivetrain is that the mounts for the transmission bolt to the case. It will just remain in place, while you remove the engine from the front of the truck. I then use a transmission jack to remove the gearbox after unbolting the circular flange of the driveshaft. A quadruplex transmission is quite long and I don't know if you could get a good, level balance point for an installation together. You will also need to have your driveline shortened as the new transmission is a bit longer. Good luck with the project. The forklift will make it a lot easier!! Rob

I'm not surprised. That is typical of their pricing schedule as discovered over the past few years. I purchased mine there several years ago, and like I said, it was near $80.00. They must be trying to harbor all or them, or don't want to sell any. I'll see this week what it will take to duplicate and make a pattern of the one I have. Besides, this is another reason to get my "wheelin" skills sharp again!! I'll keep both you and Chris posted. Rob

Hi Trent, talk to Mike at Area Diesel, in Carlinville. I believe he would be less expensive. I bought mine many years ago and if I remember right, it was about $80.00. If they have really went up that much in price, I will cut mine apart and duplicate it. Rob

Hi Trent. they make three different sizes. The website has a telephone number to talk with them and I'm sure it could be sized appropriately. Rob

Hey Chris, the air scoop is a Maradyne "Power Ram" and is still available new. It is made by the same people that now manufacture "Air-O-Matic" steering. The website is www.maradyne.com and you can find it in precleaners section. There is also a list of vendors there. I've had that scoop for several years and plan to purchase another and have it chromed after the truck is repowered. I'm going to make Macungie this year for sure!! Hope to see you there. Rob

Just like a light bulb comming on, I think you're right!! The gauge on the dash that says "Brakesaver Pressure" does have an airline running to it. Duh!!! I never thought anything about that. After work today I will have to see if it in fact works by driving down the road and applying this thing. Do you have any experience with them? Rob

Hi Herb, that would make sense as the truck does faintly have a construction company's name on the doors. There is also a air shift pto handle in the dash but the lines are capped under the truck and the pto/pump is gone. There is however, a handle sticking up through the floor that is not connected to anything. The truck does have spring brakes on the front drive axle, and the rear chambers are not spring type. I plan to convert these to spring brakes as I'm going to use the truck as a winch tractor. I do not see evidence of any "risers" ever being installed, and there is no damage in the rear to the frame area. There is a deckplate behind the cab that has a 4 inch hole like a hydraulic tank fill neck would protrude up through, or maybe a hydraulic coupler for a dump trailer. I had never seen two trolley valves and I had wondered if it had something to do with the tractor brakes but they do not apply when the handle is pulled. It also could be disconnected. Thanks, Rob

In the cab of my R model, there are two trailer brake valves. One is in the normal area on the steering column, and the other is a bit lower. The handle of the second one blocks clear access to the starter key switch. I think the truck was a dirt, or lowboy hauler, but have no idea what the second control was used for. Any ideas? Thanks, Rob

Hi Tom, The TR 72 series transmissions have an internal oil pump that operates when the input shaft turns. The oil passages in the transmission lubricate the front bearing to the input shaft. When the input shaft is not turning (as when engine is stopped) there is no oil flow and the leak will stop. What I am saying is the front seal to the transmission is bad. Rob

Hi Chris, great to hear from you again!! Thanks for the compliment. This is called "Project R-12", as per B-61 Fred's, (Morgan Heaton) suggestion. Will we see you at Macungie next year? Rob

Does anyone have an electrical and or air plumbing schematics of how the R model trucks are wired? The service manual I have is a little vague due to variations. I've got most electrical functions figgered out, but now need to tackle the plumbing side. Thanks, Rob

I'm going to try this.....

Hi Thad, I'm new to this R model designation and don't know much. My 1978 RL-755L tractor has an aluminum frame, crossmembers, front hubs, differential carriers, and flywheel housing. The hood is no thinner or lighter weight than a standard R model. It is a long extended hood, (almost 64 inches front to back). Trent has a RS-700 series and he could probably fill you in as to what is steel on his tractor. Hope this helps with your quest. Rob

The red "O" with the "X" through the middle is the low air annunciator, and the buzzer accompanies it!! Either you have a problem with an air leak, or the compressor is bad, or a bad switch. If the air is in fact low while driving, the brakes with start to apply at around 40 psi or so. You should have a pressure gauge in the dash, how was it reading? Did you notice the air pressure on either the red, or green needle showing low? You should not be able to get the spring brakes to release until at least 60 psi on the gauges. Rob You are correct as the red annunciator lamp is in fact a circle with three arrows pointing to it, my apologies. I haven't been around this newer stuff much and I did in fact think it had an X through the circle. Oh well, they say the mind is the second thing to go..... Rob

I will have to get a print for the truck to see if I can make it work before pulling the engine. Thanks, Rob