Cass 6 Universals & Shafts
Nelson Riedel, Nelson@NelsonsLocomotive.com
6/28/2004, last updated 04/08/2006

The sketch above shows the universals and shafts of a three-truck Heisler.  There are three slip joints as indicated on the sketch.    The following documents the Cass 6 universals, slip joints and shafts.  

This is the front truck universal.  This universal and the one on the tender truck are between the two axels.    The shafts driving the the pinion gears on the outer trucks are sloped so that the shaft will clear the axel.  If the universal was on the outer side of the axel, the sloped shaft would probably make the universal too high.
This photo shows the U on one end of the middle truck line shaft.
There is a U on each end of the crankshaft, one end of which is shown here.
Round Shaft U:  This is a drawing of the U that connects to a round shaft.  The  universals in the front and rear trucks and the universal at the front end of the middle truck line shaft  have this type U on both ends.  The two universals on the crankshaft and the universal at the rear end of the middle truck line shaft have this type  U on one end; the other U on these universals mates with a square shaft (slip joint).
This is the universal at the rear of the middle truck. Unlike the outside trucks, the universals on the middle truck are beyond the axels.   The middle truck line shaft is essentially level so that there is no problem with having the universals  beyond  the axels.  Also, with all the gears between the two axels, there is no room for the universals between the axels.
This is part of the universal pictured above; it was removed when the middle truck was disassembled to get at the broken shaft.    This U has a female slip joint that mates with the square end a driveshaft.   The universals on the crankshaft are equipped with identical slip joints.
Square Shaft U:   The only difference between the two types of universals is the shaft ends of the Us.  This U has a square recess to accept the square end of the driveshaft.
This shows the holes in the flat sides of a U.  A sleeve bearing fits in each of these holes.   The bearing is out of the top hole but in place in the bottom hole.
This is  the bearing that was removed from the U pictured above.
Universal Bearing: Four of these sleeve bearings are used in each universals.
The two pins in the center cross are offset by half the diameter of one pin --- a 1.5" offset
Universal Center Cross:   The dimensions in  red are estimates rather than actual measurements.
This is the pin that joined the two halves of the U joint pictured above.   The bolts hold the pin in the center cross. (The other pin has a saddle cut in the side so that this pin can pass by.  This pin holds the second pin in place via the saddle.)  The groves in the side of the pin are lubrication (grease) channels.
This close-up photo of a center cross shows the holes for the bolts that retain the pin. (I believe set screws that went only part way through the pin were used initially.  The threads in the hole were probably snipped at some point leading to the bolts .)
Universal Pin:  This shows the pair of pins required for each universal.  The 0.5" pin retaining bolt diameter is an estimate.
Cover Plate: Each end of each universal pin is covered with one of these plates.
The male slip joint is 5" across.

There are three driveshafts like shown in the drawing above.  None of the driveshaft lengths were measured.  It is assumed that each is a different length.   

All the drawings on this page have been combined into one file that can be downloaded from the Drawings page