Eaton 1100 motor rotor balls

[bwtucker 29]

In the run-up to my Eaton 1100 rebuild, I have read over and over to not remove the balls from the rotor assembly as they are all custom bored and sized together.  That being said, I removed them anyway.  I carefully laid them out to match them back up because I wanted to clean and inspect the bores.  curiosity got the best of me and I grabbed my verniers and measure the bores and the balls.  They were all identical  The one side measured 1.0000" on the bore and .9995" on the balls, on all five.  The other side was 1.2500 and 1.2495" respectively.   Is this recommended out of an abundance of caution or is the worry they wear in individual patterns?  More curious than anything.  Thanks everyone!

[pfrederi 19,131]

I Know nada about Eatons but it is interesting that Sunstrand is adamant that you return the piston slippers to the same hole in the piston block (there are 9 of them).

[bwtucker 29]

Eaton is pretty adamant too, I just couldn't see the reason why after having measured them.  

[tom2p 2,394]

Is the design of the Eaton 1100 similar to a Sundstrand ?

 

 

[tom2p 2,394]

3 hours ago, bwtucker said:

Eaton is pretty adamant too, I just couldn't see the reason why after having measured them.  

Possibly / probably due to wear pattern ?

 

The manufacturing tolerances are very tight (and on the money) - doubt individual parts need to be matched due to any manufacturing differences. 
 

I've never had a Wheel Horse pump apart (Sundstrand or Eaton) - but long long time ago had a summer job ( 3 summers ) at a hydraulics and pneumatics distributor.  They were a Sundstrand distributor.  Spent a lot of time working in the service area - and rebuilt a number of Sundstrand pumps and motors.

 

Edited October 16, 2019 by tom2p

[tom2p 2,394]

On a related note - I don't recall using the old parts when we rebuilt pumps.  Always installed a new 'circular plate' (swash plate ?) and new pistons.  Then again - they were typically scored (sometimes fairly significantly).

 

[bwtucker 29]

It seems like they have some similarities. There was very little wear on anything. The check valves were stuck open.