Forgive me if this is a stupid question, but I've got tons of them. Here's today's:

How do you drain the manual steering box? Looking at it, the only opening into it is past a white plastic bolt on the very top. Which is an interesting place to put it since I can't open it up and let gravity drain it into a pan like I would motor oil, diff oil, tranny oil, etc.. I've got one of those Auto Zone fluid pumps that I use to fill the tranny oil (same stuff), but the hose is too fat to get far inside the box, so I can't suck the old oil out from above either. FSM is no help. There isn't some kind of secret handshake I can perform on it so that I don't have to remove the box and turn it over?

 

I don't know what correct way is but I came up with a method that works for me. I used thin clear tubing (same size I use to bleed brakes) and siphoned it out a little at a time. The oil seems too thick to actually siphon but you can suck some into the tube then blow the oil out into a dip pan.

Or, you could make an adapter to put smaller hose onto your hand pump.

 

there isn't a way to drain it, without flipping it upside down. there isn't a change interval for changing the oil in there....

 

That's what I feared, but with a lack of good diagrams out there, I'd hoped I missed something. The PO was good about normal maintenance items like OEM replacement parts, regular oil changes, the right spark plugs, but the old diff and tranny fluid looked like the same stuff the car left the factory with 32 years ago, so I wouldn't be surprised if the steering oil was too.

 

Mazda never specified a service interval for the steering box oil, and there is no 'proper' way to drain it while it's still on the car. The hose-and-vacuum method is about all there is, & given the thickness of gear oil you don't all of it out.

Removing the steering box is not a job for the faint of heart. It's a challenge even with the engine bay stripped.

The FSM has disassembly, rebuild, and adjustment info, if you do take it out, but replacement seals are difficult to locate.

 

Would a larger-sized medical syringe reach in much? Or does the innards get in the way.
As others say, this is a filled-for-life unit. You could pull as much as you can, top it off, drive it a few months, repeat - eventually you would have the old stuff out.

Stu Aull
80GS (w original steering oil)
Alaska

 

I use a large syringe with no needle on it for this kind of stuff. Thats how I refresh brake fluid,
I complete suck all the fluid I can out of the master reservoir, fill with new fluid and bleed. You
can get them at auto parts stores I think.

Now I wonder what weight oil goes in there? Engine oil? Tranny fluid? Gear oil?

 

Some kind of GL-4 oil like Amsoil Manual Transmission & Transaxle Gear Lube 75W90. Same stuff that'll do for the manual trans.

 

When I was doing some research about recirculating-ball steering boxes, I tried to see what people were doing with other cars that had these. The Datsun 510 people seem to swear by changing the oil out in the steering box. Interestingly no one seems to do this with our cars. Has anyone changed the oil in their steering box and had good results, bad results, any results? Obviously you don't want to run these dry, but does changing the oil have any impact at all?

 

Honestly, it beats me how the oil ages in there. Usually, when I buy a used car, I change out all the fluids (motor oil, diff oil, tranny fluid/oil, steering fluid/oil, transfer case fluid if it's got one), do a brake flush, a radiator flush, and swap in new brake hoses, heater hoses, and radiator hoses. Those things are cheap insurance, not usually religiously maintained by most car owners, and iffy to judge by visual inspection.

At 32.5 years old and 108k miles, I don't feel terribly compelled to tear out its steering box to change out the oil before I get the car back on the road, but I've already got a spare bit of oil, so it's something that'd buy me peace of mind if I get to it in the near future. I've found that a carmaker will sometimes say something is good for the life of the vehicle when they really mean it'll last longer than the average buyer will keep it or long enough until the car is out of warranty and not necessarily that it'll last forever.

 

I too changed all the fluids when I bought my car in December, I even had chunks of rubber when I flushed the coolant out of the engine! Steering box oil seems like something that should be changed, but the FSM only states to check it, and doesn't even mention having to change it anywhere. When I checked mine after buying the car it was at the level specified by the FSM, so I left it alone.

The thing is I can't find much evidence of anyone actually draining and replacing the oil. I'd like to know if they had good results or if it was worth the effort.

 

i put redline in mine when i had it apart, and it works nicely, but then again there are a number of adjustments on the steering box, and i did play with most of them. just for the record the 81.5+ box has an adjustment for freeplay AND one for effort, so you can have loose and hard to turn, as well as no play and easy... the 3rd adjustment looks like it would really help the freeplay, but takes a crazy wrench that i've never even seen (and i worked at a Mazda dealership in the 90's when people still brought these in)

 

The thickest gear oil you can find. There is a specific steering box oil available here, it is bordering on being grease.

 

I feel like a barbarian now with my old turkey baster.

 

I just looked this up in the OEM FSM and it says use 90 wt gear oil, same at the tranny. I think
I'll change my out for the royal purple I used in my tranny.

 

I have never done this personally, but Walmart sells a syringe for measuring 2 stroke oil,it has a clear hose on the end,I use one for premixing my fuel.it would probably work great for this,I think I might give it a try

 

Unless you have a lot of play in the steering or have fixed having play or are rebuilding it. There is no good reasons to replace the oil in the box.
But if you feel the need too and are not draining it. I would recommend replacing the fluid with "like" OME fluid.
If your not taking it apart to get all the oil fluid out. You need to try and flush it as best as possible. To get all the metal sediment of worn gear, out. Mixing new synthetic in with the old oil and crap, you can't get to, can sometime be worse then leaving it alone.

 

About that play the FSM states that 1-2 inches is the spec.