
TM 9-1829A, April 1944
90/100
2021-07-07
57. Operation
a.
The drive joint is attached to the transmission or other power take-off point, and merely transmits power from
the take-off to the flexible shaft leading to the instrument. The 666-type drive joint is supplied in a wide range
of ratios (from 0.4186 to 2.3884) and is ordinarily used to correct a speedometer or tachometer that registers
fast or slow (providing instrument is correct). Such errors are caused by changing tire size, axle ratio,
transmission, etc., of vehicle.
58. Disassembly
a.
Remove case:
Take out four screws holding case together, pull case apart, and lift out intermediate gear
assembly (B and C, fig. 137). Mark intermediate gear assembly so that it is assembled in same position.
b.
Remove gear
(A): Place special tool (T-178708 Det. 4) and transmission end of drive joint (has female
connection) in vise and press off gear (A) (fig. 138). Brass jaws must be used on vise to prevent damage to
parts. Lift out drive shaft and gear.
Figure 138: Removing gear (A), using adapter tool (T-178708 Det. 4)
c.
Remove sleeve and nut
(transmission end): Place assembly on vise and, using punch (T-170742), drive out
pin which holds sleeve in position (fig. 139).
Figure 139: Driving out sleeve retaining pin
Then drive sleeve out of case (fig. 140).
Figure 140: Driving out sleeve