Tag Axles instead of twin screw

You can easily run a tag axle and have one drive axle. If going the liftable route, then a pusher axle with the drive axle to the rear is a better option. Link makes a great liftable axle. If running light, lifting it will save wear and fuel. Even if the axle is left down, not having to turn gearing in an extra pumpkin saves a little, as well as the weight savings by having one less drive axle. For traction purposes, just have the drive axle fitted with electric lockers to lock up the wheels in those areas where you need the extra traction. Just don't leave them locked up any longer than what you need to get going.

Also, since a person would be pulling the same weight and terrain as before, it is recommended they go with a 23,000 lb rated drive axle instead of the traditional 20,000 lb rating as is on most tandems. Especially if lifting the pusher.

I checked into doing mine this way recently. Can get a new Link 20,000 lb pusher axle, rebuilt 23,000 lb drive axle with lockers, new shafts, u-joints, carrier bearings, all air plumbing for around $8000 installed and out the door with warranties on everything.

 

Not the solution for every situation, but I think it has its place. I would expect the most likely application is as it is being used by the blogger you linked to... general freight. Flat bed, heavy haul and off-road would most likely not work.

You are right about single drive tandems being more prevelant in Europe. And I have seen the tag lifted over there.

I'm not sure about the rest of N.A., but unfortunately here in Alberta such an arrangment can't be run... unless the rules have changed in the past few years. In about 2003, I was building a truck for a specialized application where I wanted a single drive tandem with a liftable tag. After checking around I was told by Alberta Transportation that it would not be road-legal. IIRC, I could not run it even if the tag was not liftable.

YMMV... literally.

 

The first truck I ever drove had a tag axle. It was a air ride tag and the front axle was on Rayco springs. The tag would not raise up off the ground but I could raise the front axle off the ground.

If and when the day comes that something happens to my rears I am thinking about putting a tag on and doing away with the front rear end and power divider. Rebuilding one axle is cheaper and cutting down on weight too.

 

Tag axles were popular at one time, absolutely useless if you went into a soft ground, or slippery situations.
I was looking at a link about Wal Mart's new trucks Hybrid Cascadia's from Freightliner it has a conventional drive for the front axle and a hybrid electric drive on the rear axle.
The cruise control goes by GPS and mapping so if you are coming up to a hill it speeds up. Because of the GPS and compute mapping it know the road ahead so it know how much electric power that can be used on each up grade section and how much regenerative braking that can be absorbed to recharge going down a hill. That to me is going to be interesting.

 

All of our 2010 and beyond buys( all of the Blue& white) KW660's and Prostars at Conway TL are tags,

As they explain a weight reducing idea

 

I've never had a tag axle but I did get to witness something this winter that i'll share with you:

That huge snow storm that rolled across the US this winter shut I-80 and a few others down so I got stuck with 2500+ trucks in the wolcott, IA area. anyway I went to go to the J just east of the Walcott, and to get to the entrance you go down this little hill, really little.

And there was a LOADED MVT truck with supper singles and a tag axle stuck there for 3 hours trying to get up this little incline in the road to leave the TS...

3 thing contributed to him being stuck:

1) Super singles which offer horrible traction
2) No chains as they dont allow them
3) the tag axle so he only had 2 useless tires spinning instead of all 4 of them.


Just because you can save a little weight and money with things does not make them worth it...just my .02cents




American Trucker

 

I know a guy that used to have a 9200 daycab with a rear tag axle. It was a nonliftable type. He pulled a hopper and loved how light the truck was, but he said you had to watch the terrain when you got off the pavement, because it was more suseptable to getting hung up.

 

Supper singles are worthless anyway but I dont think MVT specs there trucks with full locking rears to make both tires pull full time. Vary few companys are gonna pay the extra cost of full lockers.
Once the mud+snow tires tread is full of snow your more than likely aint going without chains anyways.

 

I have a Volvo that will get stuck in its own shadow. If it even looks at uneven ground you better lock the power divider in. My Kw not so much, dont remember the last time I locked it in. My point being that the suspension plays a big part in how well a truck will go. Same goes with tires I would not be so quick to blame wide base singles because they have the wrong tread for winter. I've seen trucks with duals get stuck where they should not have had a problem. I dont think a truck with a tag and a single drive is a bad idea IF its set up properly. Matter of fact I think it could do better than most of trucks out there.