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I'm looking at an older model truck that has a live tandem on a Hendrickson suspension that I'd like to make a rollback out of. It has juice brakes. If I buy it, I'm going to lengthen it and I'd like to add a tag axle of some kind, preferably the kind I can raise and lower, in front of the tandems but I don't think I can get that done without air. Would the only other option be to add it at the rear?

Why do I want to do that? Well, I'm going to try and find the longest rollback bed I can find...in the mid to upper 20' range with the wood floor insersts for hauling equipment and rough stuff. The tandem might be ok at 34,000 but it would look a lot safer as a tri axle.

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What are you looking at that is twin screw with hyd. brakes?

Well....it aint a Mack. It's an 1800 series IH Loadstar. Yea I know....why build a truck like that and not put air on it? Your guess is as good as mine. It is in a cold climate and may have been a grain hauler. In addition to being a Mack fan, I'm an IH guy too and the truck in question is just soooo clean....

Roll back, you mean with a wench or a tip body? If you have a winch, do what the pulp trucks do up here, they have a chain hooked to the lift axle, lift it with the pulp loader and slide the chain in a slot of steel on the bed. In your case, winch it up, or if you have a hydraulic dump bed, use the bed to lift it. I would have an air bag axle and a dump valve, no biggy, small 12 volt compressor. You could aso drive the axle up on tapered blocks and then chin it up. On a tag axle they back them into a bank of dirt and chain them.

Roll back, you mean with a wench or a tip body? If you have a winch, do what the pulp trucks do up here, they have a chain hooked to the lift axle, lift it with the pulp loader and slide the chain in a slot of steel on the bed. In your case, winch it up, or if you have a hydraulic dump bed, use the bed to lift it. I would have an air bag axle and a dump valve, no biggy, small 12 volt compressor. You could aso drive the axle up on tapered blocks and then chin it up. On a tag axle they back them into a bank of dirt and chain them.

When I say Roll Back....I don't mean a roll off bed like used in sanitation/building demolition. I mean a wrecker bed with a winch at the front and maybe even a wheel lift at the back.

I know the IH4700 rollbacks that I used to drive had hydraulic brakes. Wreckers are only registered for the weight of the truck when empty, NOT for the total combination weight of the vehicles it might someday hook onto. That being said, hydraulic brakes on a truck registered under 26K may not necessarily need a CDL to drive. It is one of those HUGE gray areas, but could be a potential reason for that truck having hydraulic brakes. Farmers also don't need CDL's, and hydraulic brakes on a farm tractor means it would be easier to find a farm hand who could drive it. I'm sure there are other reasons why a twin-screw truck was built with hydraulic brakes...

When approaching a 4-way stop, the vehicle with the biggest tires has the right of way!

Ok ya ive seen the old tandem loadstars. Ive got a soft spot for the old cornbinders too. Well for a tag you could also do what some concrete trucks do around here they have hyd. lift tags. They are there own fully contained spring set or air bags and a hyd cylinder to raise and lower. Air bag set would be the easiest to work with just a 12v comp a tank and a regulator ant presto. If you want to get cocky use a long enough cyl. and you could use it to lift your tandems and change your tires

I would vote for a lightweight steer tag with airbags and a 12v compressor. my reasoning being with a steer tag you don't have to raise it to turn just to back up and a 12v compressor is gonna be slow to move the air needed to get 40psi in those bags. Also look into the old style spring up air down like neway they would be easier on a compressor too but id still add a 5-10gal air tank to run your valve from, gives you limited air tool capability too.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

Why?

There's a reason they made tandems with juice brakes- $$$. Yup, they were cheaper. There's a reason they don't make tandems with juice brakes anymore- They don't stop worth a damn! So you're going to take a truck that is just plain marginal- juice brakes, gas engine, single countershaft tranny- and add another axle with no brakes?

And do you even need another axle? Most of the machinery I've seen that would need a 4 axle truck to be legal would be over height on a straight truck. That's why the tractor and implement dealers have replaced their rollback trucks with lowboy trailers.

Why?

There's a reason they made tandems with juice brakes- $$$. Yup, they were cheaper. There's a reason they don't make tandems with juice brakes anymore- They don't stop worth a damn! So you're going to take a truck that is just plain marginal- juice brakes, gas engine, single countershaft tranny- and add another axle with no brakes?

And do you even need another axle? Most of the machinery I've seen that would need a 4 axle truck to be legal would be over height on a straight truck. That's why the tractor and implement dealers have replaced their rollback trucks with lowboy trailers.

Good point, how long is the truck in question? Measure center of the front axle to center of the rear axle kind of eyeballing where the bed will be and you can figure your bridge weight and get a better feel for your available capacity, with a 20' bed you can probably get in there with a 22' wheelbase and keep enough weight on the rear tandems and off the steer, good rule of thumb is to get 60% of the bed forward of the tandem center line to get your weight distributed. with a 22' wheelbase on 3 axles your gross will be 52500, go to 24' and you go up to 54000, add a tag for 4 axles in 22' and you get 56500, and 58000 for 24' if you stretch to 26' with 4 axles you get 59500. I dont know what kind of weight you are planning to haul but a light duty hydraulic brake tandem is not gonna like stopping 59500, its not gonna like stopping 52500 actually and it may not stop 59500. You might be better off to go with a little heavier truck or a lighter single axle tractor and single axle lowboy trailer, with that setup and the added length you get back up to the 58000 to 60000 legal gross category and its a whole lot easier to drive and stops a lot better too. Im all for straight trucks too and having an old IH thats in good shape wouldnt be a bad thing wither its all in what your willing to pay for and more importatnly what your end goal is.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

Do you have a pic of the truck your looking at? And that is a good point hyd brakes only stop decent empty and loaded especially with a full tandem load not to mention that with a gas engine are you going to hate your life if you have any hills to run but if you do get any speed up you it wont stop in a 40 acre field. I used to have a 1700 loadstar school bus turned into a flatbed. It had a great running 392 run great empty but with only 8000 lbs it was a dog

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