85snowdog

Here's a 1986 RD tri-axle...........A 688 though

Sorry, I'm mistaken. Mine is different.

I didn't realize those were installed at the factory. My 85 RD has one . I will take a pic of the cover that goes on it. I always thought it was something aftermarket because I had an international with the same thing.

Its changed a lot since you were here last Alex. I don't go to town anymore .......The town has come to me . Our driveway is gravel and it doesn't seem to matter how careful I am, if I wing it back there is usually gravel on the lawn that's hard to clean up in the spring.

I have one ........... It has 34 years of experience . Never let me down. Here is video of me getting home . https://www.youtube.com/watch?v=8tv51ePoEvk

Really nice find. Engines can be fixed. Exterior can be cleaned, polished or painted. But new Interior pieces would be impossible to buy. Have fun with it. Hope you keep us updated on your progress.

I've heard stories of a rag left in a lower rad hose will give the exact same problems you described .

I measured hood of my '86 RD688 and hood of '77 R795 . I'm not sure if this helps of confuses the answer. The difference between mine is 10.5 inches . I will measure the hood of my R688 , but i'm pretty sure its the same as my RD.

Really cool truck. Thanks for sharing your detroit knowledge at the beginning of thread. Its very helpful for a detroit greenhorn like me.

Thanks again for the comments . I did a short video of outside, outside and inside . Hope its ok. https://www.youtube.com/watch?v=KbIYmn0PHqI

Thanks everyone for the comments. The truck is pretty clean . I had to remove some animals and there houses . I still have more to do but work has me very busy right now. I'm not sure of mileage . The speedo is in miles per hour , so that makes me think it is original . If it was replaced at some point it would be in Kilometres per hour. It reads 125k . So maybe ? 1 million 125 k . It had one of the biggest nest behind the dash I have ever seen. And a dead animal … not sure what it was . Maybe a snow weasel .

I wanted to share my latest addition . It started life as an R795 . But the owner ( that has passed now ) liked detroit motors. So they put an 8V92 in it. I don't know a lot about the truck. I believe it has 44 k rears, 12 k front . I do know it is a 1977 , 475 hp and it has a 13 speed . I am now the 3rd owner of the truck. My plan is to use it a little to move equipment and take to the occasional show. As strange as it seems …….. my attraction to this truck is the motor. It just sounds so cool ! I plan on doing some video of it . I will post when i get something uploaded .

Thanks so much for sharing your great pics ! I'm not sure what you use for a camera, but they sure are sharp and clear. Thanks again

Thanks for the updates.

I didn't have to go to far to round up pics Rob. I just had to walk out back . lol Normally I would take tube tires off and replace with tubeless. But the old international gets about 2 mile /gal . And our gas is about $ 5.25 gal now. So the ol binder won't be going far . So I left the 10.00 - 20s on . To bad someone wouldn't build an electric truck . lol I didn't get a chance to thank keith s for sharing his build . Thanks so much Keith , Its very interesting thread.

I'm not sure if this helps. Red hub is 11R22.5 with tubeless rims . Orange hubs are tube type 10.00 - 20 's My 2 cents. Everyone is giving good advice . Tubeless is the way to go. They are easier to buy and , a way easier to get someone to work on them.

Look at the number on the puff limiter relay valve. What you describe is exactly how my R models perform with a "3x" or a "CX" relay valve on. A EM6 should have a "5x" you could even put a "6x" on it. The part #'s for them are easy to decipher. 691GC218CP6X . The higher the number and X , the lower the rpm to get fuel, but the more smoke . Remember these are mack part #'s , not volvo. I have done a lot of experimenting with different relay valves, and found there is a big difference between them. There is lots of good info on relay valves and setting the rack limiting cylinders up on here. The first pic is a "CP5X" the second pic is a "CP6X" the third was the part # for a "3X"

I kinda wish it was air brakes. I find them so much easier to work on. The truck has not been on the road since 1989. So most of the hydraulic brake components were rusted or leaking . So pretty well everything had to be rebuilt or replaced.

I have been working on my loadstar Sundance and wanted to share some of my progress . After a tune up , the MV404 runs like a sewing machine . I fixed the hood, painted the frame , polished the original paint of the cab . I put a new rad in it , cleaned the interior. I still have to clean up/ fix the running boards and quarter fenders. they are pretty rusty. I am going to clean up and paint the original flat bed and reinstall .

Thanks so much for sharing this. I'm so sorry that it took more than 7 months to see this. Its a good looking truck that is very similar to mine. Even the low miles.

I'm glad I could give you something to think about Rob. Usually I'm the one looking for help with something. Its not very often I can contribute back. I'm thankful for this site and the good folks that stop by here.

Here is a short video Rob. I think you are 100 % right about the grease zerks. I always thought they should be there . I have seen them on newer trailers. But like you said , they are usually broke or not used . I also think the teflon would be good for the slide. If everything was lubricated ,or able to slide easy , and a pressure regulator put in,. I'm sure it would be easy to find the sweet spot for the amount of air to make it work smoother. (I have a new pressure regulator for this on my bench. Been there for 2 years) lol, my problem is I have too many projects , and too little time . https://www.youtube.com/watch?v=3rg7cQP0KaQ

Its no problem getting some video for you Rob. I will get it for you later today. You mentioned the small gap between the hinge pins and the rotating sleeves. When I got the trailer the ramps didn't work very well. The hinge pins were sloppy and things would just bind up . I find the less play there is , the more energy goes to raising the ramps . I've never had any trouble since i tightened things up. To your point of greasing the slide. I actually don't grease it . You will notice no deck boards above it. That way I can wash it regularly. The grease just attracts a lot of dust and crap. For the video I put a bit of lubricant on it. So you can see how easily it can move. With no lubricant you need to give it a little help. (equivalent to lifting 20 or 30 pounds). The reason I like to" help"it , you will see that when the ramps go up . They go fast. If someone was close to them, they could easily get hurt . It actually works really good because the ramps come off the ground. I clean all the dirt off the ramps , then give them a bit of help , then they stand up nicely. My R688st has a 350 4V with an 8LL trans and 4:42 rears . I'm the second owner. Its the original paint on it.

Here some pics for you Rob. It's just a rectangle made from square tubing , sitting in a channel. Has 2 push rods (I will call them ) connected to the bottom of the ramps. I have the air spring # in the shop if you like . Its just a firestone air bag. And if you would like some measurements, I can get them for you. I can't seem to download a video directly. If your really interested I can download something to youtube for you to see. And I have to include a pic of my truck …………………Just because I like it so much.

Thanks for the input everyone. I am going to see the truck in the next week or so. I will report back with what I see in person.