niceguypmp3

no one knows the torque rating on this engine at 350hp? Also, any other ideas as to why sometimes when pulling then the truck is only running at like 1/2 throttle and then all of a sudden sometimes after 3 seconds other times after 30 seconds or so, then it will all of a sudden start pulling like it should at full throttle? it does the same thing on and off of cruise control. Also, I dont know if it's normal or not with an E7 but when taking off from a complete stop then there's a few second lag where it doesn't seem to want to hardly pull or spool the turbo. Is this some sort of emission or smog setting to prevent smoke at first pull off? It really sucks when loaded down and starting off cuz it doesn't want to immediately get out of the way and clear the intersection and then after the rpm's get up then it pulls good and hard.

I am also curious as to what the Torque rating would be on this 350hp E7?

I also noticed driving it home after purchasing it that when pulling hills, then sometimes when you put the pedal down to pull the hill then the turbo spools up but then sometimes after 5 seconds or so then it will spool up even more and it has quite a bit more pulling power even though the tach doesn't move (it's not downshifting). It does it with the cruise on and also with it off so i don't see how it could be the pedal sensor. Could this be what they call a dual HP engine? Why would it be doing this? It didn't do it on every hill, sometimes it had the extra power immediately but other times it was delayed.

We just purchased a 2003 Mack with a 350hp E7 and a 5 speed allison auto with almost 500k miles and over 22k hours on the truck. We know nothing about the history on the engine and tranny. What should we look at first or possibly replace? The trans fluid looks nice and clean and clear, it definately needs the motor oil/filter changed as it's nice and black. I already scared myself and was kinda reading through some posts about the E7 and EGR issues. How do I know if this engine has an EGR or not?

Alright guys, I finally got around to using a chisel and hammer to get that special screw out so that I could finish getting the cover off and then i find out that it doesn't look like what was being explained. I'll post the pic on here that I took. It looks like there are a couple bolts that are attached to a long adjusting screw from the back that you can see in the image. It has 2 screws that hold the whole assembly down, but it doesn't look like it can slide without hitting the gasket for the cover. I was afraid to move anything after seeing what it looked like. What do you all think? Thanks in advance!!

*scratches head* ok.... yea, sometimes figuring out things on message boards can be fun lol. I am just wondering if what my truck did is normal for the power divider switch being "out" which i assume means unlocked or disabled because when you put the switch to "in" then the buzzer turns on and when you put it back to "out" then there is the air release hiss. I just didnt know if when it is "out" then both axles should have power or not because it turned both axles when off the ground. I hope that a previous poster isnt correct when saying that the power divider shift motor might be stuck engaged. I dont know how long it has been driven like this. we bought the truck about a year ago and have never used the power divider. You'd think that if it was stuck engaged all this time, that it would of tore something out or there would be a weird noise going down the road, but everything free wheels fine.

Ok, so from what i gather from all of the replies, is that in the case I had, the truck should NOT of been able to turn both right side sets of duals at the same time when off the ground and the power divider Not locked in. I'm assuming that if it is locked in and shouldnt be and it is being driving all the time like that, that it is not very good on the rears, correct? boy, oh boy, isnt this just great!

Fjh, so what you are saying is that with the right side of both rear axles off of the ground and the power divider supposedly "out" according to the writing, then both right sets of tires will spin if off the ground? And if i lock it "in" then it makes the axles work like limited slip rearends? I hope that is what it is supposed to do, because we've been driving it this way. Surely if it was wrong, then it wouldnt still be driving after all this time like this.

On my early 80's Mack I have a question about the rear end power divider. I had always wondered why it seemed quite hard to even spin the tires on the back of this thing when on a soft surface until the other day. I had the roll off tub lifted clear up in the air and I was going to back up, but didnt realize it was up so high and it had both sets of duals on the right side just a smidge off the ground. When I went to back up, i noticed the truck didnt move of course and both axles on the right were turning at the same time. I thought, maybe the power divider was locked in, so I flipped the switch and the buzzer went off, I had just engaged it, it had already been off, so i flipped it back off and of course the air switch hissed air. I tried to move again and the same thing. Both sets of tires on the right would spin at the same time and the same speed. Is there something wrong? We've had the truck almost a year and have put several thousand miles on it and have never engaged the power divider. How does it work on this truck? Does it always use power to both rears and the power divider's purpose is to lock in the rear ends as posi? I hope this isnt in the wrong area of the forum. Excuse me if it is. Thanks everyone!

I went to turn the truck up today and I noticed that relating to the 4 screws that hold that top rear cover on, 3 are regular screws that came out easy, the 4th looks like a factory rivet thingy. Does that sound right? I imagine that i would need to pry the cover off at the same time that it hopefully prys that rivet out of the hole? I knew I should of taken a picture of it.

Thanks for all of the replies everyone. I was afraid that I would get ignored. I went and looked at the truck again, and yes, the hood says econodyne on it and the engine plate says it is a 235 horsepower 237 And it also has an intercooler. I think the guy we got the truck from said that it at one time had the engine replaced. So I dont know if the turbo/intercooler setup was from the old engine or what the deal was. I would of taken that cover off and slid that plate like maxville had mentioned, but I didn't have a stubby screwdriver with me to reach the screws. Also, It looks like the passenger rear screw is a small allen in the middle or something, so that might be fun, but the other three require a stubby straight blade screwdriver. I will let you all know how it turns out. Thanks again! Almost forgot, it also has the 5 speed 2 stick trans.

MACKS, when I first read your post, i was kinda shocked, but figured you are allowed to have your own opinion. I realize that turning up any motor for more power can possibly reduce its life expectancy. I'll explain to you how it is: It is in an '81 Mack econodyne (is what it says on the side of the hood). The truck is set up to carry the roll off boxes like waste management uses. Empty weight of the truck is almost 31k. Empty on the highway the truck can't even hold its speed up hardly any hills. What sucks is that the way it is geared, the truck is in high gear and maxed out on rpm's and can hardly hit 55-58 mph according to my GPS at which the trucks speedo is reading 63 which is definately wrong. Now if i get about 20k in the box and then i'm around 51k or so, it really slows it down, that 237 has what, 220-225 hp or something like that. Just on the interstate here on I-35 in southern iowa and at that weight there are hills that I hit the bottom maxed out at around 55 and when I get to the top then i will be anywhere from 30-42 mph and if it gets below 30 then I gotta downshift a gear because its really luggin the engine. It won't go above 30 mph in 4th gear on the high side. This thing must be geared for low speed around town driving/hauling. But I have roughly figured that it gets around 6-6.25 mpg which doesnt sound that bad. I figured if i can get even 20 or 30 more horsepower easily, that might help a bit on the highway. I don't want another 100 horsepower which would not be easy or cheap. Thanks for any help guys. I love this site.

ok, First off... when we got the truck then it was OMG gutless. I found out about the puff limiter and i unhooked it, well, now it will smoke and has probably 30% more power. But it's still really gutless. I just went out and looked at the motor/pump and it is an '81 237 with a robert bosch pump on it. Does that help?

I'm assuming that the pump will say which system it is... correct me if i'm wrong. I'll try to check today or this weekend. If there is another way to know by how it looks or something, just let me know if you could. Thanks!

I have a 198-something 237 and I was wondering if anyone could help me to know how to turn it up a bit. the truck is pretty doggy and we would like to have some extra power. From what i've read/heard but without exact details, is that under a small cover on the pump is 3 screws, one for low idle, one for high idle, and the other is the mixture/power screw. Could anyone help me with this? I would Really appreciate it.

Thanks everyone for the info. My internet has been messed up for a while and I finally got around to plugging off the puff limiter and trying it out. All I can say is WOW! This thing has alot more power now! We are alot happier than we were. We also figured out that the speedometer is about 10 mph fast for some reason. Close as we can figure, it gets around 6- 6.5 mpg which is half the trip around 55k and the other half empty at 31k and going 45-50 on the interstate. Top speed is 52 or 53 and the engine is topped out. These speeds are the adjusted correct speeds. Thanks guys.

Ok, I checked it out by using the parking brake and punching the throttle method and it seems to work. With parking brake on, it smokes a good dark cloud on full throttle. With brake released, less than half as much smoke. How doggy are these motors supposed to be. The truck that it is in is a "roll off box" truck. Truck's empty weight is a tad over 30k. Even empty, when starting to go up hills on the interstate here in south central iowa, it slows down, it seems to take forever to get to 55 mph. Today with 20k in the box, there were a few hills that had me down to 40 mph in 4th gear and still slowly slowing down and I have Yet to see it smoke from the stack. We're thinking maybe somebody before us turned it Down? we just put all new filters on it and that didn't help at all. I dont know how loud the turbo is supposed to be on these but i know that with the straight through stack it's loud enough already. We're thinking about having a local truck shop look at it and see if he thinks it can easily and safely be turned up some or if something is wrong with it. Any other ideas guys? I really appreciate the quick replies already. I'm loving this site more and more!

On our '83 Mack with the 237 we have just bought, we have noticed that it seems to be low on power. I'm not for sure on the model number at this moment, but I do know that the engine has 225 horsepower IIRC from the engine plate. I have read a few things on here about a puff limiter and that it can increase power if that is unhooked. Does this engine have one and if so, where would it be and how would a person disconnect it. From what my dad has said, "It barely, if any, smokes when your shifting up". It would just be nice to try to get a little more power from this motor. Any information would be greatly appreciated!