Gents
Ref machining the slot across the 1/4” cross feed hole in the reaction support, do you machine it down until the widest part of the 1/4” hole is exposed or all the way down to the bottom of the 1/4” oil feed hole, all the way down seems to be removing a lot of material by horizontally matching across the reaction support?

I normally take it down about 3/4 the depth of the hole, but I set it up in a milling machine and use a milling cutter to make the flat wider and cleaner, I have seen many that someone has taken a die grinder to it and cut a narrow trench in the bottom of the groove, I also make the groove diameter deeper by .050 thousands on diameter much more and you run risk of hitting a small passage that runs under that diameter (ask me how I know) and also to clean up the chatter marks and smooth the groove as best as I can, is it over kill?? yep more than likely but I have been a machinist for about 40 years and that kind of crappy work iritates me.lol

Thanks Dartman, I’ve set up in a vert mill with the hole set at TDC, I then am using a 4mm slot drill to pass trough the slot going deeper each pass, right now I have a flat bottom machined flat passing through the slot at just under half the diam of the 1/4” horizontal feed galley, you’ve kinda lost me in the second half of your explanation ref the small diam hole, I’ll take a look tonight when I get home, thanks again

And think I been doing that with a cut off wheel for 30 years LOL

I have delt mostly with 904's, 727's may not be quite the same,,while I was toying around with a 904 stator support/ reaction support and was working on the high gear apply groove like we have been talking about when I decided to go deeper with the groove to get more fluid thru the passage and to the clutch drum, and went approxamate .125 on diameter and broke thru the bottom of the groove into what looked like a small passage and ruined the part, this was done on a engine lathe after I had milled the flat, which sounds like you have done it right and I am sure it looks alot nicer than a grinder and cutoff wheel, and as far as the forementioned chatter marks in the groove,,sometimes Chryslers machining looks a little rough like they machined things with a hatchet.LOL

You can make a a pretty nice cut with a small diameter cut off wheel and a steady hand. I cut a half moon the width of the groove to the bottom of the existing passage about .750" wide.
Doug

This is another one of those mods that I question the value of. (Stand by for some mental masturbation)

OK, the hole (orifice) in the support is .1875", the slot between the rings measures .1875" wide X .200" deep, so the groove between rings has a larger cross sectional area (by about 30%) than the hole. Assuming that the entire circumference of the groove is filled with pressurized fluid intended to feed a slot in the drum that is way less in length than the full diameter of the feed slot in the support, it seems to me that the size of the original orifice becomes the limiting factor and that any increase in the slot downstream of the orifice has little/no effect.

Yes, I've heard the argument that mod smooths the transition from the hole to the slot but I'm not convinced there's a benefit there.

Interesting and valid take on the mod John, thanks to all for your valued input. Appreciated