1:1 Ford LT 9000 Twin Screw ?

[thebigo]

I have a question for truck drivers on the Forum, or anyone with the knowledge about twin screw drive. My dump truck has an air activated switch in the cab for the twin screw Differential Lock, Is this suppose to make it posi lock or just both rear axle drive? Noticed that the passenger rear wheel's on both axles drive, but the Left side doesn't, when switch is activated?

David

[Lil Giants]

It's the inner driveshaft lock so both axles get power, but only one side of each axle will spin, the side with the least traction.

[bigford]

inter axle both drives work. diff lock fully locked rears

[thebigo]

So, When the Switch is off only one axle drives? When the switch is in Lock mode, both axles drive but only one side, side with the least traction.

David

[mavrick0]

Both axles always drive. But if you get into a situation that you loose traction the front axle will put all the power to wheel with less traction and send almost nothing to the rear axle. When you use the interlock it locks both axles together so power is equally transferred to both drives. Without a diff lock you then will get the wheel(s) with the less traction spinning on both axles.

[ihbuilder]

It's called a power divider lock ( at lest on all my IH's I have is what it's called ) . The FWD rear has a differential on the input side where the drive shaft attaches to . When you switch the PDL on, it locks that diff to ensure positive drive to both FWD and RR axle . Now bear in mind you still have a diff in each axle so only 1 wheel per axle would turn in a slick condition unless you have 4 wheel lockers (or sumsuch as I never had this lux in my old trucks )also . Note ( as per instruction on sun visor )The PDL not to be used or engaged at highway speeds . It's a great feature to have when getting off road onto a dirt incline , snow or just operating off road .

[thebigo]

Thanks guy's, Just was not sure why only one set of wheels were spinning on one side with Diff lock switch ingaged. Thought I might have a problem in my diffs now I know.

David

[Brian in PA]

X2 on the power divider Steve. My Pete Triaxle had a power divider and locking axles. This provided all rear wheels to drive, a necessity with Pete air trac suspension when going off road.

[ihbuilder]

Brian , same for my 9370 when I had the IH air ride on it . Always had to lock it when getting off the asphalt .

[BRICKNICK]

Steve is correct ...

[thebigo]

Really don't notice any difference off road, although I haven't driven a semi dump for a living. Don't know how the new trucks are but, I sure think this thing is torquey...