For those of you that would like to add a thrust
bearing to your Ross 2.17:1 gear box here is a
drawing that you might find useful. The sun gear, shaft
and planet pinions are not shown for clarity.

As far as I can tell, from the dimensions that Finn gave me
and measuring the planet carrier that I have,
this is the relationship of the Ford planet carrier
to the Ross bell housing. Some dimensions are still missing
and I am not sure about the dimension marked ???.

If you remove the space between the bulkhead and carrier fingers, the "???"
becomes 0.187 .

This will of course require a different shaft and sun gear.
The design of this shaft awaits a few dimensions on the sun
gear. Right at the moment I think the ID of the sun gear is 1.45
and the root diameter is 1.82.

Sun gear ID is 1.440 according to Tracy.

Looks like a double needle thrust bearing with an OD
of 2.187" and an ID of 1.500" will partially fit inside
the 2.21" dimension of planet carrier if part of the gear
is ground down to 1.50. Obviously not practical so the
gear would have to be shortened to .950 which may
not be practical for attachment reasons.

It will not fit. Your 2.21" is 2.17" in my carrier.
Also, tracy told me the bearing MUST ride on (be piloted by) the turning shaft
and be clear of the surrounding stationary planet carrier.
So the shaft need to be turned down from the sun gear back from 1.440" to 
1.378", or 1.375" if you go with the next lower inch size bearing.

There is another thrust bearing with an ID of 1.772 and an OD of
2.559. This possible could be fitted in if part of the gear was ground
down to 1.772 which would give a wall thickness of .161.
That does not look too bad. The thrust bearing would not fit
in the planet carrier so .3"  more room behind the planet carrier
would have to be found.

1.772" ID? I don't think this would give sufficient backing (support) for the
bearing races. They would practically rest on the sun gear teeth.

No problem make a backing plate.

Also looks like that no matter the actual dimension of the missing
dimension marked ??? the seal size could be changed and
moved to the back side of the bell housing. The alignment of the
seal is way less critical than the alignment of the thrust bearing.

This would give even more room for a 2.75 inch diameter back up
plate that would fit in the current seal bore. Sort of a hat section
shape. The back side of this aluminum device could be extended
to hold the new seal. It could be pressed into the
bell housing. I will make another drawing of this part.

I think it better to forget using a pin to hold the gear to the shaft.
I think it better to warm the gear to 500 degrees and cool the
1.451 or 1.452 shaft with dry ice and press them together. Perhaps
a bit of tig welding on the ground down end would not affect the heat
treat of the gear on the other end.
Also possible is sweat brazing them together.

The shaft, aft of this, could then be ground to 1.500"
to provide a surface for  the seal to  rub on.

Paul Lamar

I wonder what the tolerances on these carriers are. These are yours vs. my
measurements:
4.16 - 4.25
  .95 -   .98
2.21 - 2.17
0.35 - 0.25

An all important measurement is the distance from the planet gears to the
bulkhead:
0.512".

Finn

With out scale drawings Finn is is very hard to follow what you say.

What did you use to measure with?

Paul Lamar
 
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