this story takes place after
CJ7 DANA 30 Full Rebuild and Setup PART V...
We install the immobilizer on the yoke of pinion ...
And you begin to tighten the nut ... so we obtain a preload between 1 to 2 Nm
Since it is extremely difficult to find a direct reading torque wrench for an individual (I toured all of the garages
region ... not Found ... ... But I found a garage who kindly lent me his torque wrench 1-9 Nm:
to show you we can do without it and show you a method that is as accurate and cheap!
I will use the buddy Newton ... no... it's not the apple... but gravity ...
A tiny hint of physics courses ... get out your notebooks ...
Everyone remembers the formula:
P = Mg
P is the weight (force) of an object expressed in Newtons (N)
M is the mass of an object in kilograms (kg)
g is the gravitational constant Terrestrial 9.8 in N / kg
Our friends the Martians will make the necessary correction to 3.7 and
our selenite neighbor to 1.7
I remind you, that they have... the first extraterrestrial Jeep !!!:
End of the joke...
Preload must be in the range 2-5 Nm (new bearings as I remember)
It's like putting a meter from the axis (the axis connected to a theoretically
massless rod) between 204g (2 * 9.8) and 510g (5 * 9.8) so that the axis starts to turn ...
A small diagram to fix the ideas ...
I'm going to use gravity to make this measurement ...
except I'm not going to put the axis at 1m (too much trouble (taking into account the mass of the rod (goodbye accuracy) etc ...)...
how do I do ...
Ben was a superb rod ... balanced (zero mass) and all that ...: our yoke...
But it has a radius of 4.13 cm (0.0413 m) ...
Never mind! Applying a simple rule of 3 and it's all good!
0.0413m should be applied to a mass of between 4.94 kg (0.204/0.0413) and 12.35 kg (0.510/0.413)
That is all ... but how do we do in practice ... Already the shaft axis of attack should be parallel to the ground:
You are not agree ? Ok! we will apply it in practice!
In our present case (I remind you that regulates the pinion depth), we must tighten the nut so as to obtain a preload between 1 and 2N.m
First, since you not believe me ... we will measure it with the wrench of the garage workshop...
I managed (by tightening the nut with a normal wrench) for a value of 1.5 Nm (The torque wrench "triggers" to 1.5 Nm.
At 1.6 Nm the torque wrench turn the pinion without triggering ) That's what we want !!!
And applying the previous formula but this time between 1 and 2 Nm.
I've done so far 5 Nm with a step of 0.5 Nm (the weight to get the figures are completely right) ... I let them)??
Those who want the little formula excel give me a PM ...
Well now there's more to the mystery object out ah! ah!
And yes! a load cell (same for fishing!) with memory to 7 $
1 - is pulled perpendicularly to the ground ...
2 - as soon as the shaft begins to rotate, it stops pulling
3 - was the maximum value stored by the ruler: in this case at 3.7 kg or 1.5 Nm at 0.0413m! it works!
and it's super accurate!
That's the FRENCH TOUCH
Now ... you can have a direct reading torque wrench ... (But much less funny and expensive )
Good! but back on topic! namely the pinion depth:
Now that the preload is 1.5 Nm, we go back to the housing to install
the fake bearing and the central rod ... (BE CAREFUL WITH THE SEALS
It installs the differential caps (always differentiated) and we tight them ...
And we install, the tool to measure the pinion depth, on the top one the pinion, ...
And it puts two
shims 0.50 mm shims to allow the comparator to go over the rod...
It installs the gauge on the block with the 2 shims of 0.50mm above ...
It is zero on the dial ...
When it's all done ... we scoop the comparator on the rod and storing the
highest value! in my case it is-0.23mm.
You need to make several readings to make sure this value!
What does it mean this?
Well we have:
57.15 mm (standard pinion depth distance)
+ 1.00 mm (2 shimm of 0.50mm)
- 0.23 mm
(measured value with the comparator)
57.92 mm (current pinion depth)
The pinion depth desired is: 57.58 mm
So it was all wrong: The pinion depth is TOO big : it must be reduced!
To do this, we must Increasing the thickness of shims
0.84 mm (thickness when measuring stalls)
(Delta necessary: (57.92-57.58))
So we need a thick shims of 1.18 mm!
who will leave with my shims 0,003", 0,005", 0.01 "and baffle shim 0.02 " as follows:
0.02 "(spoiler attached)
+ 0.006 "(2 x 0.003")
0.02 (2 x 0.01 ")
0.046 " ie ~ 1.17 mm, which is not too bad, compared to 1.18mm
So at work ... We must dismantle the pinion ... we remove the nut and washer ...
The yoke (you need to go nicely with "MC")...
The deflector ...
To be continued...