Lo-Buck 9" Ford Filler and Drain Bungs:

[drive em]

If you have a Ford 9" rear end in your rod or race car, you no doubt know the advantages to being able to swap the centersection, pig, chunk, pumpkin or jackpot easily to change the gear ratio. One of the things Ford almost never installed was a drain plug, I have seen them on some '57-'59 car and truck housings, but almost never on the later stuff. Some of the early housings have a filler on the backside of the housing, but the later housings do not. From about '67 and up Ford started installing pipe filler plugs on the front of the centersections that can be removed with a 3/8" ratchet. Because of all the variations in styles of housings and centersections, it is entirely possible to end up with a housing with no filler, and a centersection with no filler. This is usually discovered at the worst possible time, when you need to put oil in the rear end!!!!! Here is how I remedy the situation and have an easy way to drain and fill the rear end.

I buy a couple of black steel pipe couplings at the hardware store, one is 3/4" NPT for the filler, and the other is 1/2" NPT for the drain. There are cast steel pipe couplings, but you want to stay away from those as they are not as easy to weld. The steel couplings I use are smooth and have no casting lines:

I cut the couplings in half with a hacksaw to about 3/4" in length. You will also want to clean any paint or coating off with an abrasive sanding disc to prepare it for welding. Now is also the time when you will want to cut the hole in the housing. An 1 1/4" hole saw works good, but I use the plasma cutter as I usually cut the holes when I am cutting off all the old brackets. The factory installed the filler plug at the fill line in back of the housing, but I choose to install them at the top of the housing to the right of the ring gear. I know that a 9" uses 2 1/2-3 quarts of oil, so knowing the fill level is not important to me as I change to oil frequently. Installing the filler up high also reduces the chances of any leaks at the oil line, and makes if far easier when it comes time to pour the oil in :

With the filler bung placed over the hole, a couple of tacks hold it in place and it is welded all the way around:

The drain bung is the same process, a hole is drilled or cut into the housing and the 1/2" NPT bung is welded in place. I cut the drain bung to 1/2" in length. I have seen people try to tap the bottom of the housing, but it is not thick enough in my opinion and I would not want stripped threads in the housing. I like things bulletproof and simple, and this is the best way I have found. You aren't rock crawling, so clearance is not an issue:

A couple of allen head pipe plugs will keep the oil in place.
.

 

[rsanter]

yup
cheap fix

you can also get the weld on plug that uses a knureled knob for easy filling and inspection.

one trick if you put the 3rt member in a housing with no fill plug is that you can pump or pour the gearoil into the end of the axle housing before re-installing the axle

bob

 

[nissan_crawler]

yup
cheap fix

you can also get the weld on plug that uses a knureled knob for easy filling and inspection.

one trick if you put the 3rt member in a housing with no fill plug is that you can pump or pour the gearoil into the end of the axle housing before re-installing the axle

bob

You can also pull the bottom stud out and/or replace it with a bolt to drain it.

 

[rsanter]

You can also pull the bottom stud out and/or replace it with a bolt to drain it.

done that a few times
remove the botton nut and then use a punch to knock the stud into the housing so the oil will drain

bob

 

[mrpowderkeg]

I did something similar to what you have done this past spring. While at a buddy's shop everyone was BSing drinking highlifes we were talking about drain plugs on Ford axles. The only issue is getting a jack under our race cars, since the plug interferes with the jack. Some of my pals have modified jacks with a hole for the plug to go through. While doing some preventive maintenance on my street/strip car I thought about this issue, and came up with a solution. I cut a piece of 1/2 inch flat bar stock to fit the bottom of the axle. I drilled and tapped a 1/4 pipe threads, and used a allen head 1/4 pipe thread plug. I then drilled the axle where the hole needed to be, cleaned everything up, tigged the plate to the bottom of the housing, and now I can lift where my plug is. The pictures explain it better than my paragraph. Just another way to do it, and it cost me nothing but time from materials around the shop. So far, not a drop to speak of out of the drain plug. Also this could be used on off road trucks etc... because the drain plug will not get hung up or knocked out, you could radius the edges of the plate and it will slide over objects instead of catching and tearing things up, and the threads are tapped deep enough so the plug is flush and hence protected.

 

[GeorgiaHybrid]

Nice solution to the jacking problem. I like the way you think.

 

[Torque1st]

On heavier vehicles lifting from the pumpkin can cause the rear axle housing to bend...

BTW- You can also buy weld-in pipe bungs but most of us just fabricate them like the OP.

 

[Gearhead559]

i just used a $20 fill cap from jegs on mine

but i put it where i could see the ring gear

 

[Joe69]

I welded one of these on mine. It's a phoenix tank flange.

Joe