STEERING BOX DRAIN PROCEDURE 2012

[bertvorgon]

Steering box drain and re-fill procedure:

Tools and supplies:

Vacuum pump
STIFF line 1/8” I.D., about 3 feet.
Adapter, whatever, to connect to your vacuum pump.
Measuring container
Gear oil, 80/90 W.
Moly-G ( optional but recommended as these boxes are irreplaceable ) anything to help wear
Funnel and line

I had not changed the oil in my steering box for some years now, so I thought I would come up with a procedure to do this and pass it on.

James has a nice hand help vacuum pump, so we thought we would use that, to suck the old oil out. First thing is to get some very stiff, 1/8” id line. I used the truck air brake line,
which I use on all my air lines. You need something stiff, and small diameter, so it will snake around the worm gear, to get to the bottom of the box. You will need some 80/90 gear oil, and I always put in some Moly-G.

You will need a measuring container that will give you up to 250 ML.

So, remove the plug, making note of your existing oil level. Make sure you have wiped off any road grime and grit from around the plug, you don’t want that crud falling into the box.
You will want to have the fill level just BELOW, the bottom part of the fill plug hole. This will allow for some expansion, and hopefully, not too much weeping out the factory plug.

Taking your very stiff drain line, snake it to the RIGHT of the drain hole ( angle it down ), you will have to give it a wiggle, to get around the worm gear, but, it will go to the bottom of the box. We used a long piece of line, so as to have a good distance to our adapter, then to the pump. We then pumped the vac to about 15”, and the oil slowly came out of the box. Be aware that there can be up to 300 ML of oil in the box, so you may have to stop, empty your reservoir, and take another pull on it. We took about 220 ML of oil out of my box.

Now, we then measured 20 ML of Moly-G into a 250 ML beaker, and added 200 ML of gear oil into that, and stirred it up well. I actually added maybe a hair more oil, to allow for the coating that would stick to the lines and funnel,
a bit of “Kentucky Windage”

We then used a clear plastic line attached to the funnel. Make sure the plastic line does not plug the fill whole, as you may get an air lock. Basically, whatever you take out of your box, you are replacing.

Replace the plug, putting just a wrap of Teflon tape around the threads, that keeps oil from wicking out the threads.

Now would be a good time to adjust your box, follow my procedures here:

http://www.the510realm.com/viewtopic.ph ... box+adjust

I think I will do this procedure again, in the fall, after letting the trace old oil mix with the new, then, I will have a very good “change” of oil. I just did a 500 mile trip, with no sign of weepage,
with the oil level described above.

Thanks to James for his help and use of his vacuum pump, made it really easy, done in 15 - 20 minutes, for peace of mind.

As I have a LOT of Moly-G and gear oil left over...we could have a steering box flush day for local members.

[bertvorgon]

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[510wizard]

Thanks for the how do. Where did you purchase the Moly-G ?

[bertvorgon]

I got the Moly-G at our local auto parts store, Lordco, kinda like your Rock Auto, etc., I think it cost me 9.00 for the tube. I have used that in my transmissions for ever also.

[510-Trevor]

I have a bottle of RedLine MT-90 (75/90) left over from a transmission flush. Do you think it would be okay to use in the steering box?

Also, do have an english version of the first picture showing the Molyslip-G? LOL

[dislexicdime]

i usually use my vac bleeder that hooks to the air compressor to drain my box.=)

[two_68_510s]

Excellent! Great procedure and photos!

Does ambient temp have a bearing on when you do this?

[bertvorgon]

ARRG...I know when I downloaded my pictures, I had the stupid French showing...sorry guys.

75/90 is just fine, anything fresh and not the original oil is GOOD!

No, I don't think ambient is an issue. Not enough to worry about. With my level just below the bottom of the fill hole, considering the heat right there from my turbo, I have had no more weeping issues, so I think that is the criteria.

[two_68_510s]

I wonder if I can get it all out on the bench just by turning it upside down? (it is out of the car now)

[bertvorgon]

Yes, you would get 99% out of the fill whole, that would be perfect.

[qwik510]

I drained mine when I had it out for the engine swap. Let is sit upside down for a few days.

Didn't measure to see how much came out but filled it with synthetic gear oil to just below the plug.

How often should it be done?

[bertvorgon]

Unless it is getting totally barbecued with a turbo/downpipe, it can go for years! When you think that thse boxes are upwards 0f 40 years old, I bet most of them have not been changed. The problem we saw is that they were hardly ever adjusted, so the "on Center" wear is what really killed them. With today's good oils....just decide what is a comfortable maintenance regime...and be happy with that.

In my case, I bet I have gone at least 5 years since I last did mine, and the oil did not look that bad, considering the heat it has had.

As I cannot even get the HL510 steering box parts now, I figure it is cheap insurance for many more years of positive steering.