Tag Axles instead of twin screw

I agree full lockers would have been the way to go. We get way to much winter weather in the pacific northwest for that setup.

 

Tag axle that is non-lifting is useless but tag axle that can be lifted when loaded is better than twin screw in slippery conditions. Twin screw is only needed in very soft ground. If you have twin screw with only crosslock and single drive axle with difflock then single wins. Twin screw with crosslock is only 2 wheel drive and it finds that slippery spot more easily than single with locker.

 

Lenny....
I will take a tandem over a single axle in slippery conditions. When roads get very crappy, drive by the stuck single axles,everytime.
Drove a single axle one winter, several years ago. Truck was stuck on a pile of dog crap and they ride like crap.
Maybe things are set up different on your side of the puddle?

 

You forgot the 4th thing that contributed to him being stuck.... no lockers on the drive axle. No fleet is going to trust the average driver with lockers on a drive axle. If you don't use them properly, then one busted drive axle and not going anywhere.

With traditional tandems, you only have 2 drive tires spinning out of the 4. With the MVT setup, he only had 1 tire out of 4 spinning. Many times, cat litter will take care of the no chain issue. You are right about the super singles being worthless with that setup on ice.

But that is what you get from a company based in NM and not the upper Midwest.

 

i think that you guys need to thought on diff rating

as i am informed 6x4 american tractors are mostly rated at 62-63-4ton

for example here 4x2 6x2 trucks are rated at least at 60ton some of them have even stronger diff about 80ton sometimes even more even up to 125tons

so you need to take stronger diff

also i know for a one tractor here imported from us and converted to 4x2 it has several diff breakdowns

also this tag axle truck should have less tire wear than with non steerable twin tire pusher setup

also this
i notice that 6x4 us trucks have thinner chassis rail than our 4x2 trucks so you can maybe have problems with chassis when tag/pusher is lifted under full load

 

I meant single drive axle with tag that can be lifted or at least with dump valve, and diff lock. We have twin screws for logging and other hard jobs that have liftable second drive axle to get more grip in winter.

 

Back in the old days we mounted the air control valve in the cab and when it snowed or rained or you got off the pavement you let some air out of the pusher or tag axle. The tag will ride better than the pusher but if you put a lift on it you have to be very carefull where you have your 5th wheel at as in making contact with the trailer gooseneck. The pusher works better as in when you let some air out of the pusher you have added traction on the drives and the steering. A little rougher ride though. With a lift on a pusher and a 48" sliding 5th wheel you can slide the 5th wheel all the way back when empty or loaded light and run with the pusher in the air. Either set up saves on weight and pulling resistance. The 23K rear end is the only way to go. Nearly indistructable! Back in the late 70's i owned a 427 Chevy with a 5sp and 2sp rear end (5&2) with a liftable pusher pulling a City Weld 3-9's. They hated me with a passion at the west gate of the Ohio turnpike.

 

Lenny and Admiral are correct. A liftable or dumpable tag axle with a 23,000lb locking rear end will outperform a normal tandem in nearly every way. Better traction in slippery conditions, burn less fuel, less tire wear, less weight. As it was said only shortcoming is in soft ground conditions the single with tag will get stuck much more quickly.

 

Cool blog---thanks for listing.


i can't comment about snow or bad weather or off road but i when i was with overnite/ups freight they were big on the jiff-lock thing---which becomes essentially a tag axle. Works great on dry pavement and i generally feel every tractor should be spec'd this way.

 

I've ran this very setup for 2 years worst mistake of my life so have to disagree with you both. No traction even with locker excessive tire wear we're talking a set of super singles on drive axle ever 45,000 to 50,000 miles and no added fuel mileage but I did shed 500 lbs weight