On Steering Box Lubrication : (or how to mix your own MSI grease at home)
Hi all, this is a technical post about steering box lubrication.
I have found, in my travels, so many HQ – WB steering boxes, that (on opening) had been lubed with General Purpose Grease or straight Moly Grease. This is the wrong lubricant! Eventually it messes stuff up.
The correct lubricant for HQ – WB steering boxes is Castrol MSI grease… but… Castrol stopped making this years and years ago. After seeing so many steering boxes filled with hard set, (translucent golden orange) aged GP grease, and stiff hardened Moly, I came to the conclusion a while back, that when MSI became unavailable, many owners, service yards, and perhaps even large franchised automotive service chains, assumed the practice of replacing the MSI with whatever grease they had on hand that would seem to do the job.
Have you ever been doing work on the steering, had a steering box out for the first time you’d looked at it, and found that when you turned the input shaft you got full travel, and no apparent play or improper slack, but the action of the box felt lumpy, had more friction crossing some parts of the arms track, or a seriously gritty feel though the shaft to your fingers?
GP grease goes hard and crusty at the edges in these steering boxes over time, and Moly grease sort of sets into a crackable soft putty type of substance in a similar way. Both tend to retain some residual lubricating (normal look and feel) of fresh grease toward the centre of these boxes though, which, fortunately, and considering the strength of the gearing and bearings, allows them to keep working alright for the meantime, (gotta love that) but, these greases are too stiff even when fresh to meet the proper design spec.
When they really crust up, that’s when you’ll feel a steering box input shaft and it feels so grungy you’d think its unsalvageable, but… not necessarily at all, it could just be that its full of old hard crusty GP or Moly grease.
OK, a word of caution, steering boxes do wear out, so you need to be thorough in your evaluation, and its easy to imagine a box that is really gummed up with the wrong grease is going to wear faster than one that is properly lubricated, I suppose that depends on circumstance, (it may have been sitting) so I’m not saying all steering boxes are salvageable, but many will be and I reckon the following is worth knowing;
If you need to service your steering box, you’ll obviously check the lubricant to start with, it should be fluid, a bit like the consistency of flavored yoghurt for instance, - it should spill out (fairly) easily when you open the lid of the box and tilt it over.
If the lubricant is yellow, orange or golden, like old GP grease, or if it is thick and black like old moly, and especially if it has hard set crusty grease, it has been greased with the wrong lubricant.
You’ll need to clean that out, you can do it without disassembly but don’t leave any cleaning fragments behind of course (the broken off bristle of a toothbrush will do just as much injustice to the thing as hard crusty grease, or worse).
Now, refill the box with 0.255 litres of lubricant to the standard of Castrol MSI, which you can mix up easily.
(I first spoke to Castrol Technical about this around two years ago and got the advice to simply mix a Gear Oil with Castrol LMX (Moly) in a 50:50 mix. However, before posting today, I checked again with Castrol Technical, and the advisor went and had a chat with the other Castrol Oil heads (for about ten mins) and they discussed two other formulas and decided on the best one)
Advised :
1. Castrol Edge 25w 50 mixed with Castrol LMM (Moly) Grease at a 50:50 ratio.
(this was the consensus on the closest possible perfect mix).
2. Castrol EPX 85w – 140 Gear oil (Diff oil) and Castrol LMM at a 50:50 ratio.
(this would be very slightly thicker, but so close it took a while for them to decide)
3. (As per my advice from Castrol around two years ago, pretty much any gearbox oil with Castrol LMM Moly at a 50:50 ratio – the technical guy explained that its just got to be runny enough so that it doesn’t run out, but gets down in the rollers etc.
So, there’s a few choices there as to what you have in your workshop, and the oil product could probably be from any brand, but seeing as Castrol gave the advice for free, and are the recommended lubricant manufacturers, well it’s nice they knew what they were talking about 30 years later on for free on the phone.
Anything close to this of course will increase the working life and wear on one of these steering boxes way more than straight Moly or GP grease.
Here’s one I prepared earlier.
[Insert simple pic of gear oil being mixed with LMM in a clean margarine container here]
Further notes:
The likely chances are, if you have a reason to replace a box with a second hand one, the one you find at the wreckers will be full of hard crusty grease because the box came out of a Kingy, Belmont or other, and most Australians owning these cars were not performance specialists, or even home mechanics, they were family vehicles and many owners would not have even known what the steering box was, they just trusted their service agents (many in the 80s offered ‘multipoint lube and safety point services, just before holiday periods) I have had to wonder if there became an accepted practice to refill the steering box on HQ – WB with whatever GP grease seemed most appropriate and on hand. Then, the next person who opens the box just refills with whatever they observed was in it .. perhaps, with no MSI available, and so on.
Anyway, I hope this post helps anyone looking at lubricating, inspecting, or rebuilding a HQ-WB steering box.
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Originally Posted by Gunna Do
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