TM 5-2420-230-24-1
Spicer Speciality Axle Division - Technical Publications
OVERHAUL INSTRUCTIONS FOR TYPE D66 DRIVE HEAD UNIT WITH DIFF LOCK
(AS FITTED TO STEER DRIVE AXLE)
GENERAL DESCRIPTION
The drive head features an overhung spiral bevel pinion mounted in widely spaced taper roller bearings
which are adjustable by graded spacers.
The drive is transmitted through the heavy section crownwheel and differential assembly, again running
in taper roller bearings, and adjustable by special nuts, running in the differential straps.
A variety of pinion and crownwheel combinations are available, covering a wide range of ratios.
A differential lock, operating on the drive shafts, is available as an optional extra.
INTRODUCTION
Very often noises and vibrations originating in other parts of the machine, are mistakenly believed to
eminate from the drive head, with the result that time and effort is wasted on an unnecessary
dismantling operation. Therefore, before fixing suspicion on the drive head, investigate all other possible
sources of trouble. Where the drive head is definitely suspect however, draining the housing and
examining the oil for metal particles will aid diagnosis and help to pinpoint any malfunction.
Check the following defects and note the possible cause :-
a)
Vibration
Broken gear teeth / worn bearings
b)
Continued noise
Worn bearings or gears
c)
Overheating
Loss of lubricant
Spiral bevel gear adjustment tight, seized bearings
d)
Noise on turns
Worn side gear and pinions
Worn or damaged trunnions
Loss of lubricant
Worn drive shaft splines
e)
Loss of drive
Broken drive shaft
Stripped splines on drive shaft
Manual No. 1785 Issue A
Page No.C2
Spicer Speciality Axle Division
J-66
