Hi Gergo,
Here is my experience and what my local rebuilder does and recommends. As I
say, so far I have had zero success at doing it myself despite trying several
times (not healey diffs though). My best attempt whimpered at 50kph, my worst
howled constantly and made people look around in wonderment.
After your parts arrive, firstly assemble the pinion bearing and cups, then
set the pinion preload by adjusting the shim pack at the front. Do it without
the seal fitted, only fit the seal at the very end. The 'starting value' they
refer to is the thickness of the big bearing washer next to the pinion teeth
which should be approx 0.215". This is just a starting value if you don't
have the original. I'd start with the original washer.
The manual says 180-200g.m pinion bearing preload which my rebuilder thought
was a bit high after he had a feel of it set to that. I got a 2m pole and
mounted it on the pinion flange bolts in the middle. I then hung a 190g weight
at the 1m mark and It just started to turn the pinion. This is purely trial
and error changing shims and requires torquing the pinion nut each time (only
once you are close, initially hand tight is ok).
Then fit the crownwheel and set the side-bearing preload. It is supposed to be
2 thou but this correlates to approximately a firm one-finger push on the side
bearing washer to install. Just a little preload, definitely no slack. You can
use washers and shims out of other makes of diff, mine now has Ford Falcon and
Nissan Skyline washers and shims.
Next step is to put some marking fluid on the teeth and run them firmly
together back and forth a few times to make a mark. If you are very lucky it
should be in the centre of the crownwheel teeth driving side and not running
off the ends at all. Say a little prayer to the Gods of Speed if you are this
lucky.
Moving the crownwheel sideways by changing the side washer thicknesses shifts
the mark from outside to inside of the crownwheel (toe and heel) and moving
the pinion in/out by changing the thickness of the washer behind the big
pinion bearing shifts the mark from the top to the bottom of the tooth (face
and flank). This is opposite to what you'd think at first glance. If after
several hours of fiddling about you get is a mark that runs off both ends of
the crownwheel teeth then your gears are worn out. There is no cure for this
apart from a visit to a Gleason lapping machine or new gears.
The whole procedure is long and frustrating if you don't have the right
thickness shims and washers. Each change in pinion depth requires pressing off
the big pinion bearing and either replacing or surface grinding the washer.
Near enough is not good enough, it equals a whiner and you can't tell until it
is driving down the road. The marking on the crownwheel must run centrally
across the teeth in a 'bean' shape when you are done. I have never been this
patient.
Good luck,
Andy.
|