Mack 300 w 2070 trans.

[nedly05]

Is the mack 300 HP and the 2070 a good combo for a tandem? I know mack built them this way for a long time, so it must be a reliable set up. How do you shift the 2070? Its an air shift. Are they a tough trans? Thanks. Ned

[Ford LT-9000]

I don't know what model tranmsission that is what is it ?

Most of those old Macks used back east were 6spds around here Macks have 8 LLs or Mack 12spds. A 6spd isn't enough gears you really do need more gearing to keep the engine working at its best rpm range and have any decent road speed.

Mack never really built trucks for the user friendly they are more for durability a 300hp tandem axle is underpowered coupled with a 6spd your leg will fall off double clutching.

Around my area most gravel trucks are no less than 14 litre power with minimum 400hp with 8LL 13 or 18spd behind the engine. When your pulling a 10% grade hill you want some power also going down the hill you want a strong holding JAKE.

[nedly05]

I agree about the big motors and trannys, In my search for a good truck, I keep seeing the macks with these specs. They must be a good setup if they made them so long.

[Ford LT-9000]

It all depends on how much hauling you want to-do if its just a occaisonal hauler then it prolly will do if you want to haul everyday then I would look for a truck with minimum 350hp and 8spd. If I was going to buy a Mack it would be one with a 350hp and 12spd Mack transmission.

[Orchard Ex]

I think I read somewhere that Mack used to rate their HP at the wheels instead of at the flywheel like most companies, so the power ratings look lower on paper. Not sure of the tranny's by actual number (2070?). I drove an R series with a twin stick 5x2 for a while. 1-5 were on the left stick and L,D & R on the right as I remember. Used to turn around way far away from the loader in the pit, then start "gettin' gears" in reverse.:bouncegri (I guess I got bored staring at that bulldog's butt all day)It was no speed demon, but I wasn't left in the dust either. It was as tough as nails and rode like it too.

[Steve Frazier]

When the drivetrain is all Mack, IE, engine, transmission and axles, the horsepower rating is at the wheels. If they are mixed components, then the rating is at the flywheel.

[nedly05]

Any idea of a what a 300 HP with a mack trans would be at the flywheel, instead of the wheels, would it be around 350? Thanks for the good input!!

[Orchard Ex]

When the drivetrain is all Mack, IE, engine, transmission and axles, the horsepower rating is at the wheels. If they are mixed components, then the rating is at the flywheel.
Come to think of it - it was probably on this forum that I had seen it. I forgot about the "all Mack" part though. Thanks Steve!

[nedly05]

Has anyone ever driven a 7 speed mack? Is it a straight 7, or do you drive through 3 gears, go to high range and then go through four more? I'm sure that there is a high and low range, and it is air shift, just wondering about the pattern. Any infor would be appreciated, I have heard a lot of good stuff about these trannys, just not how to shift it!

[Ford LT-9000]

If you are trying to find a Mack try find one with the 12spd its the best transmsision Mack made. Minimum would be Mack 8spd or 8LL the 6 and 7 spds have no range boxes. A Mack 12spd shifts kinda like a super 10 Fuller but much stronger transmission.

[MSC]

It's been a while, but if I remember right here's how to shift a Mack T2070.
Without a load, range selector in direct, shift it like a 5 speed, 1st is down in the lower left corner.

With a load, range selector in L,1st, 2nd, move range selector to D, back to 1st, 2nd, 3rd, 4th, 5th.

Someone correct me if i'm wrong on this one, but that's a Mack 7 speed if I remember right.

Rich

[nedly05]

Thanks for the input, I had thought that was it. How was that tranny to drive? Was there a shortage of gears?
Ned

[nedly05]

Any one know of a nice tandem or tri Mack (RD) for sale?

[Jeff D.]

Nedly05,how about a "CX" Mack??I'm willing too move it at the right price.(free)

Just let me know when you're coming to pick it up.I'll leave the keys in it,and I'll even fill it up with enough fuel so you can get home.When you get home,call me and I'll call the insurance co."My trucks gone,Boo-Hoo!!"

Just keep it under cover for a while,and It'll all be good!!

(I'm just joking............Or am I???)

[nedly05]

Jeff D,

I hope your joking, I read about all the trouble you had with it. We had an 85 dump, I really cant say too much bad about it. It needed a ton of work but it could have been made in to a really nice truck. It was a converted Road Tractor, I think I am going to try and go with a truck that was born to be a dump truck. Willl you ever have another mack? It's a sharp looking rig!!Maybe you'll have better luck with the next one!!:wink2
Nedly

[nedly05]

Jeff D.
Look I found you a dump truck

[Jeff D.]

I may have just gotton the lemon.Mack has a good reputation,and I imagine it does for a reason,but I've grown cynical since I've had mine.

I think a T-600 Kenworth,or possibly another Freightliner next time,for the road truck.As for a dump truck,I haven't enough experience to know what's best,in the new stuff.I've only messed with the old ones so far.

Good Luck,in your search.I'm sure there's exactly what your looking for somewhere.Ya just gotta find it!!If you buy a Mack,it'll probly last you forever,but I'd atleast shy away from the CX's.I don't know if they've the bugs out of them yet.

I'd better crawl in mine right now,before Im late for delivery.Have fun!!

[Ford LT-9000]

Myself I'am not so sure about the new Macks either there are a few guys around here buying the Granites 713 but they don't look like the one Ned posted. They have the squarish hood and round headlights.

A brandnew Mack Granite with a 16'6" Western style box tandem axle runs around 140,000 Canadian.

The new Sterlings LT9500 with 475 Cat power 20-46 axles same box will run 130,000 dollars.

The problem with Mack is they are still dealing with small engines they are still using a 12L engine trying to put out 460hp. Nothing still replaces displacement so you really can't beat a ISX Cummins or a C-15 Cat.

The Mercedes engines that are used in the Sterlings with the 450hp rating is about the same as Mack another 12L engine.

[Jeff D.]

I'd heard that Mack was going to put the new large cube Volvo motor in them(at least in their new Pinnacle) I went to their website,but couldn't find any info to confirm that.

They did mentioned their new MP7 motor,but that's only 700cu. in.

The red one Ned posted is a CX Vision like mine.That most likely started out as a road truck,too.

[MSC]

Thanks for the input, I had thought that was it. How was that tranny to drive? Was there a shortage of gears?
Ned

I liked it, it seemed to have plenty of gears to do whatever you needed to.
Even out on the open road, it seemed good. The truck I ran had a 300plus engine with this trans, 58 rears, RD688. Definitely a rugged truck.
I would buy one.
Rich

[nedly05]

Thanks Rich, this seems to be a popular spec Mack, probably what I'll end up with!

[Ford LT-9000]

If you can find a mutt aka a Mack with Cat or Cummins power you would be better off. You need a truck with 14L power don't kid yourself if your dealing with a 300hp dump truck you will be exhausted after a day of driving it.

[jmac]

As most of you guy's know I bought a 89' Mack RD690 with just this spec 300 HP and 2070 tranny. Stuff I had done was new air to air, brakes, and had a short at the fuse panel fixed them all. This is my take on the truck so far after close to 3000 miles. The truck is built like tank, very simple to work on. The guy that I have been hauling loads with have new Macks, ac, 12sps, etc. They like my old truck and say the RD is what made Mack what it is today and the new trucks have some problems with them, including the Granites.

The good points are:
very tough truck, built like a tank.
cost under 30k
will last for a million miles.
very easy to fix when needed
very strong jake
the low gears are low, and never need 1L and 2L but use RL all the time.
very stable in the turns but rides rough.

The bad points are:
very hot with out ac
the 2070 tranny has to be doubled clutch and took a while to learn
could use more gears but can keep up with new trucks a flat land but slower in the hills. The smoother I got at shifting the stronger the truck got, In other words the truck is alot stronger now after practice, shifts diffrerent with load on than empty. Very fast emtpy.
Does beat you up after a day of trucking but got used to it after a while.
Have to look very hard to find a good used old truck under $30k

For my first real dump truck very happy with it and glad I bought it. Have made more money with this truck in two months hauling material than I would ever made with my single axle. IMO I believe that if you are going to buy a old dump truck Mack is the best because of how they made the old RD's. I would also add that if you are going to spend the money to buy a truck, buy one that you can haul material with part time, I wish I did this the first time. You have to have a truck that can move 14 yrds. Any days I am not excavating I haul material for about $500 a day and it helps with the bills.

[Jeff D.]

They like my old truck and say the RD is what made Mack what it is today and the new trucks have some problems with them, including the Granites.

I've heard the very same things, and by my experience, it must be true.

The smoother I got at shifting the stronger the truck got, In other words the truck is alot stronger now after practice......

I've noticed that if you can keep the turbo from spooling down inbetween the shifts, it will pick up the next gear much better, and it sometimes makes the difference on whether the truck will pull a hill in the next gear up, or not.(by keeping the turbo spooled up)

I wonder if that's why you're noticing it, now that your shifting has improved??

Glad to hear it's working out good for you!!:thumbsup