David wrote:

Hi Paul & ACRE enthusiasts,
Regarding a recent inquiry about the remachining of the ross psru's and
installing the needed thrust bearings, I have the equipment and the
skills
to do that work. It would be best if I could organize several to do at
the
same time all in one setup. If you would pass my e-mail address along to

the person who inquired, he/she could contact me.  harborview@rivnet.net

Many thanx to you Paul for taking the time to do this newsletter. Dave

Thanks a bunch Dave. Since Ross disappeared there probably is quite
a bit of overhaul and repair business out there.

BTW I dug up some lube mods that some people have added. Here are
a few pictures.

Paul Lamar

Paul ,
Of particular interest to me is how the internal lube works - I see pipes
going in but how does that feed the respective parts. Or how should it be
done - any opinions
George (down under)

There are some differences of opinion on this Tracy feels the sun gear
needs to be pressure fed with oil from within the shaft. That implies
a plain bearing somewhere in  the system. Others feel splash
lube is fine. The original Ross fed engine oil to the prop bearings
only and relied on the excess to find its way back to the sun
gear. That has worked in hundreds of units. Some units have
shown signs of sun and planet gear spalling or other forms
of gear tooth distress but I am not convinced it was caused by 
the lack of lube. Towards the end of the Ross supply the machining 
accuracy and consistency of the Ross gear box deteriorated and some I 
suspect where not machined concentric or had other machining 
errors.

Most that are now modifying the lube system merely direct some 
engine oil directly to the area of the sun gear from behind the sun gear.

A larger problem has been getting too much oil out of the gear
box. Apparently pressure would build up in the box
and the rear input shaft oil seal would leak badly. This too
could be related to a machining problem. A more likely
scenario is a classic drain back problem or lack of proper
venting.

Like a turbo charger the size of the drain back tube is critical 
as the head is minimal back to the oil pan and the oil is froth. Some 
have gone so far as to add an electric drain back pump. If you 
put the drain back under the rotating ring gear on the 2.17 you can use
the ring gear itself as a pump sort of. Tracy takes this approach
and apparently so far has had no drain back problems.

Others running a 2.85 with fixed ring gear are not reporting
drain back problems so I suspect proper venting, proper input oil
flow restrictions and large drain back tubes (1/2 to 5/8) do the job.

Paul Lamar
 
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