oilburner

The 15 speed and a 300 Mack with a 4.44 ratio I drove would pull right with a 425 cat. It could hav been a 350 that's what the owner of the truck said it was but it looked like a 300 it had that tip turbine on it. It was a good set up

I have never seen a one stick 12 speed how did that work, I had a guy tell me he had a 12 speed in a r model once but it was a one stick 10 speed that shifted like a super ten. If you like a deep reduction and a close ratio with a overdrive I would go with a 15 speed fuller.

Is it 1,2,3, in low then 1,2,3,4,5 in direct that's how the 8 speed Mack that I have seen shift

That is a good looking old super dog. I would really like to own but a long way from old Kentucky. It having a non Mack drivetrain will turn a lot of Mack guys off but they just don't understand the old big cam cummins. By looking at the pics the engine looks like one of the better cummins at least a big cam 3 and may be a 4 it had the holset turbo and pulse manifold so this one will whistle when you get her in a pull lot better then what the truck came out with in 80 the old 290 were good engine but they could have used a little more power or at least torque. If that truck was for sale close like the rest of the guys said I would get her. And if it were mine it would cost a lot more than what your asking you just can't find these old trucks in that kind of shape and anything that needs to be done to them you can do your self. This truck would be a great owner operators first truck and with the cummins all I would do is slap a jake on it and roll. Good luck

Ok now I have done it again. You all ready have the big overdrive. For some reason I thought you had a 10 speed. Yea your as fast as you can go unless you stuck a brownie box in the middle.

My truck has a 5.13 ratio and a 107x six speed and 24.5 tall rubber and it will do 56 mph at 2100. Now if I had a .60 overdrive that would give me 40 percent more speed so I would be at about 20 more mph on top. So if he had let's say a 7 or 8 speed with the big overdrive even if he had a .71 over now he would gain 5 or 6 more mph on the top end

Well looks like I stuck my foot in my mouth. Looked at the ratio charts and David you are right. It is a .71.

You may be right David but I am pretty sure the Mack nine speed is a .60 at least I thank they made one like that. A guy I run with had a old dm with a six speed in it and it would do about 62 mph. He swap out the six speed with a Mack nine and it would do 80 mph with the nine speed. And it still had a pretty good low hole for pulling out loaded

Well looks like I should have read all the post. The engine is already apart. Let us know how it ends up

If you let it set and idle does it start hazeing blue smoke that will burn your eyes.

That is a good looking dm.

I am not sure what overdrive you have but Mack makes a nine speed that had a .60 overdrive. With tall 24.5 rubber and a 505 ratio and 2100 rpm that would be close to 80 mph maybe 78 or so

I drove one once that done the same thing but if you did not pre select it pull it out of gear then put it in high range it would not grind. I like the nine speed Mack. It has a good low and a overdrive that will put you in the clouds.

You might go with a Mack nine speed. I maybe wrong but they are a .60 overdrive and they have a good low hole. If you have enough motor to pull out the big jumps in the ratio of the trans

The dynatard is on the rocker arms. They are pluggers that keep pressure on the push rod and hold the valves open and i have seen the cams go down with the dynatArds the jake is a box that bolts on between the head and valve cover that has slave pluggers in them that make contact with the vavles and hold them open while the push rod still do there thing and I believe the jake is not as hard on the vavle train. The stealth set up works good when it is right I would say the best jake on a Mack but they are hard to get parts for the exhaust brake.

ok sorry about the miss typed number of springs in the last post, they were 10 leaf anti sway, I got a new set from morgan truck parts in London ky for 650 a side and got them on and rollin now, they are a good place to get old mack parts.

You could have a loose front wheel bearing, or any wheel bearing for that matter, but changing when you turn the wheel maked me thank you have a front wheel bearing going down, maybe jack it up and check it out

I not sure what your using the truck for but 4.17 with a mack 13 speed and low pro 24.5 will get you 80 mph at 1900, in the ch I ran, so the eaton 18 speed would be about 2100 at 80 I thank with low pro 24.5, I belive the mack tranny has a bigger overdrive than the eaton.

If it doesn't have a pyrometer in it you will need one, drove a 300 mack once that was a dang hot puppy and had to keep a eye on it.

nice truck, but that picture is from the future, 2048!! LOL just kidding, what is under the hood and floor of that ride

That is for sure not a jalopy, that's a superdog put her in the wind for me one time!!!

The ch I drove was at about 28700 with a pitts double bunk trailer that was 10,000 it self, the truck was a single frame with 44 rears and a 2130 trans. I thank your weight is pretty good I know a guy who got a old pilot truck which was a peterbilt that was 16,000 empty put it had little rears and a m11 cummins with aluminum crossmembers and all aluminum wheels. He also had a western star heavy spec tractor with a 36 foot tribrook high side dump and it and the truck was 44,000 lbs. I know it nice to have a light truck so you can haul a little more but sometimes its better to have a few more pound and have the truck for the job, but I have seen some light cabovers,

237 is a good motor. I don't know if a 350 would fit in that DM.

oh yes they are the same engine more less, the only thing different is the aftercooler on the top of the engine for the tip turbine set up and I belive I would have to get a air cleaner with the two outlets on it, but I am pretty sure if that will clear then it should go right back in the place of the 237, but I would need to change the trans or the rear end ratio if I did that get a overdrive or get the 5.13 ratio out of the rear that 237 uses enough fuel, a 350 would drain the tanks in no time. LOL!

I would like to find another engine, maybe a 300 or 350 to build as I get the money, you know a little at a time and then I will be ready if something ever happens to this one, I have found a truck with a 350 in it 2 vavle like mine but someone has put a tipturbine set up on it and I thank the 350 were all air to air, but the engine plate clearly says it a 350 hp, and it has a 13 speed eaton with it, would this be a good engine to get and swap out latter on