MTFCA Forum

Does any of you change the oil in the rearend on a regular basis? Like yearly? Every 5000 miles? Or not?

I would say if one disassemble the rearend for any reason, one pour new 600W (or SAE 250 gear oil) in the rearend, and then you check the level at season start for example, but isn't that it?

And yeah, I ran into a discussion about this.

I change the oil in my rear axle every few years. I drilled and tapped my passenger side axle housing for a drain plug to make oil changes easier.

Stephen

I have a Ruckstell rear end. Not a leaker. But I check it at the start of the season and the end just to see how much if any the level dropped. Then I usually change it every 3 years regardless of how it looks. A quart of 75W-140 (synthetic) is a whole bunch cheaper than a new Ruckstell.

I put a drain plug in every axle I rebuild and recommend changing the axle oil every season. I believe it makes a huge difference in the longevity of the rear axle components. The drain is in the right side housing at the lowest point.

Nice job Adam. I just drill and tap mine and do the same to all the rear ends I do. Unless the engine oil has been flowing down the tube and over filling and with the amount of driving I do in a normal season, never really worried how often it got changed.

I like the idea of a drain plug. I s it difficult to drill and tap. Is there enough material in the case wall to tap? Would grease on the tap to keep metal out? Would it be tapped pipe thread or macnine thread?

This is what I do to the ones I overhaul. Drill and tap for 3/8 npt [/size]

I have done some that are still installed in the car with lube in them. Most of the chips come out as you drill and tap, rest with the lube as it slowly drains out. You can also put grease in the hollow parts of the tap to trap a lot, then a quick flush and fill.

Ordinarily, draining the super thick 600 wt. oil (grease) takes a very long time and much of it sticks to the walls and will not come out, contaminating the new oil you put in. If you have a lower drain, it will speed up the draining process if you apply air pressure to the upper port. Drain out half of the oil and fill with a half quart of mineral spirits and mix by attaching a tube and agitating the oil and solvent with air pressure. Then allow to drain. This would be a good time to dismantle rear, clean thoroughly with mineral spirits and coat interior of pumpkin with “Glyptal” to make the interior of the pumpkin slick to aid in future oil changes. Jim Patrick

But if Henry ment it should be changed - why not ad that drainage plug from factory?

With just 20 HP it's not a very hard loaded rear end.

Henry didn't add a drain, only a fill hole. The Instruction Book states to check (every 1,000 miles) and add if level is low. I do that each annual inspection, and add if needed, most times none is needed with modern inner seals. If your rear axle drips and leaks, then check more often.

Now if you feel inclined, most all of the old 'free' 600W can be pulled out of the oil fill hole with suction gun, run the T to have the rear end lube warm helps to drain, just like engine oil should be warm to change. Then replenish with new using the suction gun. Have done it about every 5 years or so.

Now my Ruckstell has a drain from the mfg. on the Ruckstell housing. So that 90W pours out pretty quick, and can pour in a new quart, into the Ford side fill hole, with the nozzle of the container. Have done that annually, if a lot of tours that year.

Dan. Does running the T create enough friction to warm the rear end oil? I would think that using a heat lamp or heat gun would warm the oil more efficiently than running the T. Jim Patrick

If drilling & tapping and adding a drain plug, it seems like perhaps a magnetic drain plug would be a good idea, not only to hopefully attract ferrous metal particles that occur from future normal wear, but also in case any metal particles are inadvertently left in housing from drilling. What do you think,.....???

Mine is only tapped for 1/4" pipe thread, maybe takes a little longer to drain but works fine. Any larger then adding a support might be good. The casting is not real thick so 1/4"PT is good enough. As the size goes up the thread count goes down, so would have less thread to engage in the thin casting too seal.

Mark. You’re right. The pumpkin wall is very thin. Could you build up the lower drain plug area with a 1” diameter mound of brass brazing, then drill through the brazing into the pumpkin then thread the hole for the plug? This way, you could have a bigger plug. Jim Patrick

You could do like Adam shows in that post, but the 1/4" works fine so why go to all the extra work. OK it does look nice doing it that way. By the way, I use an Allen head brass plug, so it does not stick down any more then it has too.

Pipe threads are tapered so that a plug will tighten as it goes in, hopefully not being over tapped so that the plug goes all the way through. The thicker the stock the more threads you have and the less likely that this will happen, otherwise, you will need a plug with a shoulder so that there is no danger of it going in too far, but, if the shoulder mating surfaces Jim Patrick is not perfectly flat, it will leak. Jim Patrick

jiminbartow wrote: ↑

Sun Feb 14, 2021 6:21 pm

Dan. Does running the T create enough friction to warm the rear end oil? I would think that using a heat lamp or heat gun would warm the oil more efficiently than running the T. Jim Patrick

Jim

Yes. The action of a warmed up T will cause a rise in temp in the operating systems. Draining engine oil is best done by warm oil. Run up to operating temp, then let the T cool down some. Otherwise the oil will be too hot to handle

This thermal image was done many years ago, I think by a poster from down under, don't recall who to credit. But you can see the rear housing warm, as it also gets blasted by hot exhaust gases from the muffler.

When I was checking my barn fresh buckboard find before returning it to the road, I checked the rear end, and found it grease filled. So I put the plug back in and motored on. I have no idea when it was last filled/checked before it was taken of the road in 1956. Should I heat the diff hot enough to make the grease flow to get the stuff out so I can refill it with 600wt oil?

Allan from down under.

Allan

IMO, take that unknown rear axle apart and clean, inspect for old worn or about to bust Babbitt thrust washers, or other parts, replace, clean, assemble with modern seals. Then refill with fluid 600w.

I'm curious Dan T. - how did you determine that Ruckstell (mfg.) installed a drain on that housing ? I have seen a "boss" in the housing casting but never a "factory" plug - I've built over a dozen Ruckstells & have yet to find a housing with a factory drain.

RajoRacer wrote: ↑

Mon Feb 15, 2021 10:50 am

I'm curious Dan T. - how did you determine that Ruckstell (mfg.) installed a drain on that housing ? I have seen a "boss" in the housing casting but never a "factory" plug - I've built over a dozen Ruckstells & have yet to find a housing with a factory drain.

Assumed to be mfg. installed, maybe this was a far up North thing? My axle is Canuck

Interesting - thanks !