Sliding Tandem Axles

[Big Bill]

The sliding tandem axles on a trailer are customarily used to shift weight along the drive line of a rig - distributing weight to and from the steering axles, drive axles and then the trailer axles.

However, you might find these sliding tandem axles to be beneficial in other ways. Some of those ways are to slide your tandem axles forward and backward to accommodate certain driving and backing scenarios.

For example:

Inner City
If your negotiating city streets you might find it a bit easier sliding those trailer axles forward. Doing so cuts the lazy tracking of your trailer wheels. In other words, by sliding your trailer’s axles forward you’ve cut the turning radius, or sharpened the cutting edge that the trailers wheels will follow the tractor. However, beware of the “kick-out” that the tail of your trailer will have on the back end’s sweep, as you turn. To see exactly what I’m referring to, go into a parking lot and practice. It also helps if you splash some water on the ground to see the sharp tracking of your trailer’s wheels, then notice how wide the tail end of the trailer swings out to either side. Have someone else drive so you can visually see these effects from a lot of different angles. If you’re concerned about being overweight on any one of your axles, don’t. Scales and other “testing” devices are not used in the inner city. However, if your going in between cities you do want to reset your axles if you think the load is still a weight problem.

Closed In Docks
Some docks are closed in and provide very little light to see exactly where it is you backing. If these docks aren’t equipped with dock lights, guide markers or other devices, one of the last things that you want is to have a trailer wander on you. One way to lessen the back end of your trailer wandering is the slide your tandem axles all the back as far as they can go. Hence, you’ve lessened the impact of the trailer’s tail for every turn of the steering wheel - left and right. You’ll also find it a lot easier controlling your trailer’s drift. Normally, your trailer’s reaction distance rolling back and then turning as a reaction to the steering can range from between 5 to 15 feet. And to a lesser degree if your tractor is angled at the start of your backing. But then again, go to parking lot, splash some water on the tarmac and see the impact of this adjustment to your backing. If you can have someone driver while you watch you’ll the dramatic differences.

By the way, if you haven't experienced this already -some shippers and recievers will require the trailer's axles to be all the way back so as to lessen the drop of the trailer's entrance against the dock.

In any eveny, those were just two of the ways of using your equipment to make life a little easier.

[vwaggs]

Sometimes you'll discover they don't want to slide properly because the brakes are improperly adjusted on the trailer. Using a rock or board in front of the tires or backing up against a curb can be very helpful in aiding your adjustment. Remember if you back against a curb to slide SLOWLY you will find it hard to correct an over adjustment.

[GearJammer88]

another plus to sliding them all the way back before backing is you dont have to worry about the tail hanging over, or very little

on a 53 footer the tandems usually leave it seems 10-15 feet of tail behind them, when backing you gotta watch that and your wheels

thats how trailers get scraped up

[Cerberus_Kelpie]

Another tried and true tactic that works for most Drivers when sliding Tandems is to have a reasonably sized spray container with a diluted Soap (Dish washing detergent works well) solution. Mix as you please.
Just spray liberally on BOTH SIDES of the track and it should then slide easily or easier even with a 44k load.
One can as well spray even when the tracks are wet from rain.

One should however lower the Landing Gear when heavily loaded to avoid damaging the King Pin and Fifth Wheel as well as Clutch, Drive Train and Patience.

[DemolitionMan]

When I was a city driver I always slid them all the way up anyway. Now that I am linehaul, I still slide them up enless I know the tandems are heavy as hell, then I slide them back. We have a scale in ATL, and since going there everynight I discovered that sliding them does not change the weight on the drive a whole lot. Keep in mind my assigned tractor is a single axle.

[soonk]

Originally Posted by Cerberus_Kelpie

Another tried and true tactic that works for most Drivers when sliding Tandems is to have a reasonably sized spray container with a diluted Soap (Dish washing detergent works well) solution. Mix as you please.
Just spray liberally on BOTH SIDES of the track and it should then slide easily or easier even with a 44k load.
One can as well spray even when the tracks are wet from rain.

One should however lower the Landing Gear when heavily loaded to avoid damaging the King Pin and Fifth Wheel as well as Clutch, Drive Train and Patience.

lower the landing gear while sliding tandems? for sliding the 5th wheel, sure, but I don't see how this would do anything but cause problems during tandem adjustment. please clarify for one who wishes he knew more!