Description
For Sale: All Nation Power Truck, Small Gear Unit NOT Assembled PN#9027K
Parts List PN#9027K (aka 4062) Kit Constant Torque Transmission
If this product is out of stock, please contact us to get on our waiting list. Let us know which type of mechanism is desired and how many will be needed to complete your project. We will contact you when they are available on a first come first serve basis.
Our photographs illustrate the gear units in a P&D Power Truck in different configurations. The P&D Power Truck sideframe and bolster is not for sale. These are available from P&D Hobbies.
We recommend the reader become knowledgeable about worm and worm gear mechanics, characteristics and terminology. Generally known as a Worm Drive consisting of the worm on the drive shaft and the worm gear on the axle, in this discussion below we refer to the worm gear on the axle as a spur gear even though this type of gear box worm can be regarded as a special case of a helical gear whereby the teeth on the axle worm gear are slightly angled.
Based on the original All Nation blueprints, the draftsman identified this gear unit as PN#4062. It was later renumbered in our catalog as #9027 and is sold with or without the Power Truck. The Tower Gear End numbered #4056 later renumbered in our catalog as #9056 for the helix gear implementation or 9056C for chain . The chain drive utilized Serv-O-Link parts and is a smooth running noise reduced mechanism.
The insulated wheel must be determined on which side of the transmission before mounting on the axle.
These gear units are available with various length drive shafts coming off the worm. Depending on how the gear unit is used, a double shaft may be desirable if powering the trailing truck in an engine.
Our drive units have been used not only in our F3/F7 and NW2 engines but also in other makes of diesels, Gas Electrics, M.U., Trolley/Traction models, Steeple Cabs to name a few. If a diesel modeler wanted dual powered trucks, our part numbers under auxiliary drive gear units were #9026 for F3 & F7, #9041 for NW2 Diesel Switcher or the more general number #9000 replacement truck. For this reason, side frames are not included with the constant torque drives because frames are usually part of all diesel loco kits or used in another manufacturers engine. For example, Kemtron GP-7, ALCOs and Traction cars utilized our gear units in their respective side frames. The traction cars often went with the 33″ or 36″ wheel sets in both 2 rail and uninsulated wheels for traction.
We tested our drive units in a new P&D Blomberg Power Truck side frames. The installation went perfectly well with only a minor modification. First, the journals were a perfect size for our axles and the tolerance is so close, 1 out of the 4 journals needed only a little burnishing or polishing for a perfect bearing surface. Second, to install the tower drive, the one piece bolster braces needed to be turned upside down to allow for perfect drive shaft clearances between the wheel sets. This modification did not affect the performance of the power truck.
Comparing this gear unit to the ones we produced in the past, it should be noted that we improved our engineering to discontinue the use of steel sides on the gear housing PN#4039 and replaced with polycarbonate sides to reduce resonance noise that can be generated by the gears. The part number will remain 4039. In addition, the unit now comes with a bottom cover for the spur gear. This housing again is to reduce noise but also keep the gear clean and well oiled. The housing snaps on and off and is a good retainer for the #4037 axle bushing. The 4040 spacer bushings for the drive shafts are drilled and tapped for either a 2-56 or 3-48 by 5/32″ machine screw so the entire unit can be disassembled and serviced. The kit version of this small gear unit may not have the holes in the spacers drilled and tapped.
Made In the USA.
The breakdown of parts for this gear unit follows:
Parts List PN#9027K (aka 4062) Kit Constant Torque Transmission
Drive Shaft PN#4045 1-3/4″ Long
2 Spacer Bushing For Drive Shafts PN#4040
1 Spur Gear i.e. Worm Gear for Axle PN#4052
2 Brass Axle Bushings PN#4073
1 Axle PN#1524
4 3-48 x 5/32″ Filister Head #C1301
12 Thrust Washers aka Shim Rings (note unit may only need a couple for fine tuning)
2 40″ wheels PN#2146 and PN#2147 (note may be substituted for 33″ or 36″ wheels)
2 Wheel Insulators
4 Lock Washers #C2034 or C2031
1 Worm #4051
2 Gear housing Side Panels PN#4039
1 Bottom Spur Gear Pan with 2 Retainers & 4 Screws 0-80 x 3/16 Screws 3D Print PN#253AN
Our photographs illustrate the gear units in a P&D Power Truck in different configurations. The P&D Power Truck sideframe and bolster is not for sale. These are available from P&D Hobbies.
