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1.
This is measuring how much the bearing for the pinion shaft
protrudes from the surface of the intermediate plate. The measurement
here is 0.323". |
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2.
This is measuring the depth of the recess in the cover plate for the
above bearing. The cover actually goes over the main shaft bearing,
too; but we are only concerned with the pinion shaft bearing. The
reading here is 0.314”. This dimension is subtracted from the dimension
in [1] giving 0.009”. From that we subtract 0.003” which is the preload
[amount of squeeze] on the bearing. We now have 0.006” which is the
thickness of gasket to put between the cover and the intermediate plate
to give the correct preload. A variation of +/- 0.002” is allowed here;
so I installed the closest I had available, which was 0.005” thick.
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3.
Here is where I should have shown the separate shaft assemblies. This
shows the main shaft and pinion shaft in tool no. P-55. I'm adjusting
the height of the main shaft so that it is properly aligned with
the pinion shaft. To do this, I'm turning a threaded collar that
supports the main shaft.
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4.
This shows me tapping the main shaft bearing in the intermediate plate
with an appropriately sized piece of pipe to get it started on the main
shaft. |
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5.
Now we have the assembly in the hydraulic press to press the assembly
together.
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6.
Here is the assembly after being pressed together.
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7.
The shift rods, shift forks and detents have been assembled loosely to
the cluster. It is time to adjust the shift forks, tighten their pinch
bolts and tighten the detent plugs. I use blue Loctite on the threads
of the detent plugs and tighten them to 18 ft lbs. The next step is to
rotate the shift rods so that their heads are parallel and equally
spaced. The camera should have been a little lower to look straight
into the heads of the shift rods.
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8.
The important goal here is to have the operating sleeve centered
between the two gears. About 1 1/2" above the fingers on my right
hand you can see the shiny ends of the spider that positions the
operating sleeve. There is more showing on the left than on the right
so the sleeve has to be adjusted slightly to the left.
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9.
Here we see the operating sleeve centered between the ends of the
spider and consequently, centered between the gears. The pinch bolt,
seen between the fingers on my left hand, holds the fork to the shift
rod can now be tightened. I use blue Loctite and torque them to 23 ft
lbs. This is tighter than the factory specifies but we don't want them
to come loose. I've never stripped the threads in the bronze shift
forks.
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10.
The mandrel that is part of tool P-33 is inside the case and is a
sliding fit in the bearings in the side covers. The mandrel has
shoulders that abut the side bearings and the length of the tool from
shoulder to shoulder is stamped on the tool. My mandrel is 5.594". In
the photo the mandrel is resting on the right side bearing, as
the trans case is rotated 90 degrees from its normal position. The
mandrel is pushed upward to contact the left side bearing and the
travel distance is measured with the dial indicator. In this case
0.140". [The dial indicator has made one and a fraction revolutions.]
Adding the 0.140" to the 5.594'' length of the mandrel gives 5.734 as
the total space between the side bearings.
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11.
The width of the differential between the side bearing contact surfaces
is measured. In this case it is 5.432". Subtracting this dimension from
the space determined above gives the total thickness of the left and
right side shims to fill the space. Actually, 0.006" is added to this
to give the correct preload for the side bearings. In this case
that gives a total thickness for the two shims at 0.308". Additional
work is required to determine the split of the total thickness into the
left and right shims to give the correct backlash of the ring gear and
the teeth on the pinion shaft. The total thickness of the two shims
must remain at the 0.308" -0.310" [There is a tolerance of +0.002"].
Thus, if one shim is made 0.003" thicker, the other must be made 0.003"
- 0.005" thinner.
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12.
Here we are measuring the clearance between the fulcrum plates, often
referred to as "trunnion blocks", and the inner end of the axle as the
parts are assembled into the differential side gear. This is done with
both axles and their respective side gears and fulcrum plates. The wear
limit for this clearance is 0.010”. Yours were less than this but I
like to get them back to the tolerance for new parts, which is 0.002” –
0.006”. By using new fulcrum plates we were able to get 0.004” and
0.0025”.
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13.
This is supposed to illustrate the parts of the differential-axle
assembly. Unfortunately, we neglected to include the spider gears, the
shaft for the spider gears and the pin for retaining the shaft in the
housing. In this pic these parts, along with the axles, have been
already assembled into the differential housing and differential cover.
The small parts in the center are the ring gear bolts and their lock
plates. Note the 3 studs screwed into the ring gear. These are used as
an aid in aligning the bolt holes in the differential housing flange
and the differential cover.
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14.
Here the differential assembly is being drawn together by tightening
nuts on the 3 studs in the ring gear. Once the parts are drawn tightly
together the ring gear bolts are assembled and the studs removed. [The
studs have a slot in the ends so a screwdriver can be used to remove
them.] I use blue Loctite on the bolts and torque them in stages to 58
ft lbs and then assemble the lock plates. One lock plate fits in
grooves in two adjacent bolt heads. The “arms” of the “U” shapes in the
lock plates are squeezed together and then the outer edges are bent up
against the flats on the bolt head. There is very little clearance
inside the transmission case for the edges of the lock plates so it is
necessary to go around each one with a hammer and tap any protruding
portion inward. |
[1] I usually have to have the parts stripped of old paint and
different blasting media is used on the casting than on the other
parts. [2] The bell end of the axle tube may be deformed slightly and
thus require excessive gaskets under the cover plate to give freedom of
rotation against the spherical surface of the aluminum side cover on
the trans case. If the customer’s tube requires excessive gaskets, I
will use a tube from my supply, sometimes checking two or three to find
one with optimum fit. [3] the cover plate may be distorted and not
provide a flat surface for the gasket[s] and sealant. I attempt to
flatten distorted plates but sometimes can’t get them flat enough. In
those cases I change to another cover plate from my supply. This is the
toughest place on the trans to prevent leaks. [4] It is much easier to
assemble the new solid boot. Some people stretch them over the bell end
of the axle tube but sometimes tear them in the process.
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15.
In the upper part of this pic is the bearing housing and axle tube. The
lower shows the brake line clamp, solid boot and the cover plate. Many
people do not disassemble the axle tube but I do it for four reasons
listed below the photo.
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16.
This is a V W tool for supporting the axle tube when pressing the
bearing housing onto the tube. It is improper to press the housing onto
the tube by merely placing the bell end of the tube on a press plate.
That tends to distort the bell of the tube and resulting in the problem
mentioned 1n 15 above. Note that the tool supports the actual end of
the tube and not the bell.
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last updated 1.28.2006
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