Thread: getting old fluid out of ford 9"-bowl

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Since the housing of a ford 9" axle has that "bowl" kind of at the bottom with the bolt surface that lips up, how do you drain the fluid out?

If I just crack the pumpkin I don't think more than half of it will drain out, the rest will sit down in that bowl.
My gears are new so I want to make sure to get all of that break in oil out.

Yeah!! An excuse to get another tool!! Just in time for Christmas.

Any excuse to get more tools is a good excuse!!!

Another option would be to drill a hole and weld in a bung for a drain plug, next time you change gears you wouln't have the problem of getting all the fluid out.

Tell me about the break-in oil. I have new gears in an 8" rear but just put in gear oil "once and for all". Actually I have "changed" gear oil once in an old Ranchero rear but at that time the service station had a suction pump like Bob showed so I would think if you have it serviced at a lube shop they should be able to pump out the old oil, but what is it? Are you just worried about tiny metal particles and just need to change the oil or is there some special break-in oil that I never heard of?

Don Shillady
Retired Scientist/teen rodder

I just always thought that when you have any new stuff like a tranny or diff you should replace the lube after the first 500 miles or so.
I realize they are hardened but don't you still get some tiny shavings from initial use?

While on the topic, is there an ideal viscosity I should use? Mine is a trak-loc.

Castrol Hypoid C lube 85-90 for street Trac-Lok. Add friction modifier to it. All available at Autozone. Change it as often as you wish, it's cheap insurance.

I find it's better for me to just change fluid if I'm unsure because otherwise all I do is think about it.

thanks guys

In terms of "what is it?" I like to get to the chemical structure and a similar situation occurs related to medicines. All the trade names are mostly meaningless without a chemical structure but you have to ask the drugist for a spec. sheet to get the formula. Even the stuff on the Internet seldom gives the real chemical formulas. In this case I actually worked on gear lube additives for Socony Mobil back in the early '60s when the hot formula was to add thiophosphonoesters to the petroleum base oil (they are what gives rear gear oil the characteristic odor). That REALLY works and seems to form a coating of sulfur-phosphate compounds with the iron surface. We used a "four ball" test where a pyramid of four 1" ball bearings was weight-loaded on the top ball which was spun at about 50 rpm. With the additives the test would go on for hours with no change in the balls but without the additives the ball bearings would gall and scuff terribly and the petroleum base oil would smoke a lot in just a few minutes! NOW some colleagues at nearby Ethyl Corp. Lubrication Lab tell me there are even better new additives but of course unless you read the patent literature they just give meaningless trade names. Tech1 thanks for the retail name, I guess I never considered changing the gear oil, just adding as needed.

Don Shillady
Retires Scientist/teen rodder