A little backgound: I run the Silver State Classic in my '67 Charger with a 496 stroker and a 727 turning 2.50's in a Ford 9". I've walked 2 extension housing bushings out of the housing with 2 different transmissions, yokes, driveshafts, rearends and pinion angle setups, both times at speeds of 140+ for some amount of time. D/S balance and runout are very good, and the most recent output shaft was measured for runout at under .001". It was hand-picked for that fact before being used, The only thing truly in common is design and operating conditions. No application that I can think of uses a 727 auto at those speeds for anything more than a short burst, not the 40 minutes at a time that I do it for. I am convinced the rear yoke is starving for lube. Both failed yokes had significant galling. There is relatively little hard acceleration and braking, limiting the fluid movement from slosh. Fluid temp is usually about 200-210 in the pan. D/S speed is 5000 rpm, and well below critical of 6800.

I am going to pressure feed the rear bushing just like a main-bearing by adding 3 lines to the rear of the housing. I understand from the manual it works between 5 and 25 psi, which is ideal. I'll drill through the bushing at the housing at the 12-4 and 8 o'clock positions, with the 12 o'clock being drilled directly above, but air-gapped over the existing hole. The top fitting will also have a restrictor in the fitting (nitrous fitting and jet) to control pressure to the other two. The other two would be offset forward and backward respectively and drilled through the housing and bushing. This will make the top position a passive feed into the existing hole and the other two feed whatever pressure is left.

Now to the questions:
1) Does the return FEED the rear bushing in the housing by the sprag, or is it a passive return that dumps into the case?
2) As such, can it be bypassed and use my rear bushing as the dump, since one of the 3 new lines is ( or can be) free-flowing? If not, I'll tee into it.
3) What is the restriction after the return hose that causes there to be pressure? A free-flow return would not have pressure.

I can answer #1 , yes the return line going to the rear of the case is what lubes the rear support/mainshaft interface.

The return fluid from the cooler enters the case, lubes the rear support and then travels forward through the output shaft to lube the planetaries and the input/output shaft interface.

For your purpose, I would think a tee fitting that routes a single line with a control orifice to the rear bushing would suffice...multiple lines might rob needed lube for the planetaries. In your case you might even consider installing a caged needle roller bearing which would need less lube but I don't know if the slip yoke surface is hard enough to survive.

The factory lube source for the rear bushing is a "spine" cast into the top of the tailhousing (red arrow) that depends on a sort of capillary action to route fluid to the top of the bushing where it spreads via criss-cross channels in the bushing. Fluid drains through the rectangular slot at the left.

Well that answers quite a bit. I'll be sure to share the circuit, not re-route it. The bushing that is in the replacement housing is evidently a teflon lined piece that if I remember correctly is a Ford application. Supposed to fit tighter. It does not, however, have the grooves. I am going to add them with a die grinder. Are you suggesting using the existing hole to just let it pour in, or leaving the passive drip feed at the top alone and going through the side with an extra?

I too thought about going to a needle bearing, but I don't think the yoke would survive.

If you leave the drip feed, pressure might bleed off through it; I would install the bushing upside down so the hole is at the bottom, then drill and tap the beefy portion of the housing at the bottom for your feed line.

Is the bushing you are having trouble with the Ford bushing? Or are you turning out the Chrysler bushing, and contemplating the Ford as an upgrade?

Since the bushing in there has no grooves, maybe it makes sense to use 2 "pressure" feeds in the driver side, one in the forward 1/2, and one in the aft half with the passive hole at the top center. Yoke rotation would keep the film moving around the shaft, away from the passive feed in the top center. Top center would still be there unaltered doing its thing.

I have walked out one of each. The Ford bushing is being used again as it removed a little bit of freeplay in the yoke. The intention there was to keep runout to an absolute minimum. I don't like the lack of groove, but the teflon and the additional feeds ought to offset that.

hi
there are babbit or bronze bushings for the 727.

have you tried both ?

Never tried a bronze. Why would it do better than the other 2 types?

what is the part number of the ford teflon bushing ? what transmission is it used in ?
TIA

The Ford C6 and Mopar 727 share the same rear bushing and seal. Transtar 36066T is the Teflon bushing.

thanks John.

i have a 71 dart getting ready to install a 440 with indy cyl topend with dual plane intake .i have a breather that has a 1'' drop the breather filter is 3'' tall . the question i have is my hood gonna close completly with this setup or will i have to cut hole in hood ? all info will be appreciated

that is one of those which we need to know which Indy heads, which intake and which carb?
Ypou may need to go to a 2 or 3 inch drop base bottom to get the air cleaner to clear your hood. If it does touch the center brace you can remove it to get a little more clearance, I've seen that done way more than once that worked real well
The Max Wedge cars came that way stock: up: Made the hoods lighter also

my engine has indy ez1 heads indys dual plane intake 850 mighty demon carb