Triumph Repair: Spitfire Rear Axle Re-assembly, hub flange, rear axles

Question
Jim - I am rebuilding my '78 Spitfire 1500 rear axles. I am in the
process of assembling the rear trunnion and positioning it on
the axle shaft. I'm not sure how far along the shaft to drive the
main bearing onto the shaft (and therefore position the
trunnion). I have not yet tried to mount the wheel flange (hub).
Once that's on, as you know, you can't make any more
'adjustments'.

Both the Haynes and Leyland manuals only talk about where to
position the grease 'flinger' at the back of the trunnion. They say
to position the front of the flinger at 5-3/4" from the threaded
end of the axle.

If I assume the back edge of the trunion is where the flinger sits,
then the back of the trunnion housing itself would be at 5-3/4"
from the end of the axle. However, the trunnion housing is
2-3/4" deep, the wheel flange (hub) is another 2-1/16" deep,
and the axle threads are 1". All this adds up to 5-13/16", which
is 1/16" too long!

Since the face of the main bearing is flush with the front of the
trunnion, it would be helpful if the manuals indicated where the
face of the main bearing should be from the end of the axle,
rather than relative to the where the flinger is. (On my axles the
flingers will drift all over the place between 5-3/4" and 6-1/8"
from the end of the axle. Maybe they're just too loose? )

Does the hub flange, when tightened down with the axle nut,
mount flush with the end of the axle (i.e. the non-threaded start
of the axle)? If so, there doesn't seem to be enough room unless
everything is meant to slide along another 1/16" when I torque
down the hub. Or does the flange/hub torque down to 1/16" off
the end of the axle shaft, which would then add up to 5-3/4"
from axle-tip to trunnion-end, and place the hub flange directly
against the inner race of the trunnion bearing?

Right now, I have positioned the main bearing race (and
therefore the front of the trunnion) 2-1/8" from the NON-
threaded start of the axle, which might leave me with a space of
either 1/8" or 1/16" between the end of the hub flange and the
inner race of the runnion bearing. I'm not sure if this is correct.
When I looked at the old wear patterns of where the bearings
and seals were before, it would seem to be correct. But I'm not
sure there should be a space between the flange and the
trunnion like that.

Can you give me any advice? Am I on the right track here? Many
thnx for any experience you have on this.  

Answer
Ross,

Ok, with a bit of digging I think I found the answers you're looking for.

I'll just give the instructions straight from the Triumph Herald 1200, 1250, Vitesse, and Spitfire Shop Manual, Second issue.

Re-assembly

Using Churchill Tool No. S300A, fit the needle roller bearing into the trunnion (pressing on the lettered end) to a depth of .5" (12.7mm) from the trunnion face.

With the sealing lips trailing, drift the inner oil seal into the trunnion.

Drive the flinger onto the axle shaft using the tool shown on Fig 10.

Pack the needle rollers with grease and pass the axle through the trunnion, taking care not to damage the inner oil seal.

Secure the axle shaft in the protected jaws of a vice, pack the ballrace with grease and drift it onto the shaft, using Churchill Tool No. S304, as show in Fig 12.

With the sealing lip trailing, press a new seal into the seal housing.  Coat a new paper joint with grease, position it on the trunnion outer face, and assemble the seal housing, brake backplate assembly (with wheel cylinder at the top) and grease trap (with duct to bottom).  Secure the assembly with bolts and new lockplates.

Insert the key into it's keyway in the axle shaft and ensuring that the tapers are clean, fit the hub and secure it with a plain washer and a new nyloc nut.



Ok, as to the figures.  Fig. 9 nicely shows the cross section of the outer hub, and the axle shaft protrudes from the hub 2.625" from the face of the hub to the very end of the axle shaft.  

Fig. 10 is the tool to set the flinger and it's 1.5" outer diameter, 1.020 inner diameter with the inner bore 6" +/- .002".  The open end is tapered down to 1.24" diameter.


Cheers,

Jim