Pierce Arrow Society 1994 #2.
The transmissian is charncterized by having twr: sets of
herringbone gears. The rttaisr qear train is herringbone and the
third spe& herrinqbun~ EC@? designed with fine-pitch gears in the
front half of the harringbune and large-pitch gears in the rear
half, riveted togethes;. In asseabl~, the main shaft has to be
timed to the coun~e~:shaft, If not properly kimsd, this will
reslllt in a very high gear naise, There have been several
occasions in the club in which members have re-assembled a,
transmission without regard for ths timing marks and have written
for help. The solution is to take the transmission gut,
dismantle it and re-assemble it wikh the timing masks on the 7
gears assembled i this transmission
works very well and is quiet,
The main and secondary gear trains are herringbone wi+h
- m w w. Therefore, they will functisn at D
location on the periphery of the gear and only in one relative.
location which is timed and marked on the gears, If the unit is
assembled with one lone tooth off, it will howl like a banshee or
hang up.
The shiftable cc&al unit, a large diameter double jaw
clutch with every other tooth stopped off, has fore and aft
movement and has a, tendency to wear ridges in the spline shaft
which can cause rough shifting. After decades of-use, the jam
clutch teeth become burred as well as the teeth in the
corresponding gear faces. The shiftable unit ,called the
ltpineapple", must fall of its won weight on the splines when the
shaft is oiled with SAE 20 engine oil and inclined at an angle of
20 degrees off vertical.
When the transmission is disassembled, all parts should be
laid out on white paper, after washing in VARSOL or kerosene (NO
GASOLINE) each should be inspected for burrs, nicks or ridges
with a jeweler's 5X loupe. Any and all parts should be either
stoned or ground with a small
inequality may be found.
f8Dumoreql hand grinder until_ no
It is a good idea to replace all transmission bearings with
new bearings.
_- Use a straight mineral grease of 160 weight such as Texaco
Thuban or equivalent.