TR2/3/3A Proper Oil for TR-3 Steering Box

[af3683]

I would appreciate it if someone could please tell me what is the proper oil for a TR-3 steering box. I need to add some and am not quite sure what to put in. Thank you.

Art

 

[Don Elliott]

I use 80W90. Many say they use a grease-like lubricant from New Zealand and/or UK called Penrite. Since I have a one-piece steering column, there is a rubber plug down below the coil on my 1958 TR3A where I can top up my steering box. I use the oil because I have no leaks from my steering gearbox. The owners where their steering boxes have leaks use the grease.

 

[TR3driver]

Penrite is strictly a band-aid, IMO, and will make a bad situation (heavy steering from a worn-out box) even worse.

I use Valvoline full synthetic 75W90, which is a GL-5 rated gear oil.

BTW, my split column TR3A also had the rubber plug for topping up the steering box.

 

[af3683]

Thank you. I'm not sure what's currently in the steering box. Therefore, should I avoid using a synthetic. Not sure if you should mix synthetic and non-synthetic. Also, what is meant by "GL-5" ? Thanks.

Art

 

[TR3driver]

Should be no problem mixing synthetic and non-synthetic. But if it worries you, or you want to be sure to get the full benefit of the more expensive oil, it is easy enough to drain the box. Just loosen the 4 bolts on the front and leave it for a few hours, then tighten them back up.

"GL-5" is a performance specification for gear oil, issued by the American Petroleum Institute, that covers things like minimum protection from wear, scuffing, corrosion, thermal breakdown and so on. You can read more about it at
https://en.wikipedia.org/wiki/Gear_oil

I mentioned it only because there has been a long-running debate in vintage car circles about GL-4 vs GL-5, with some people insisting that one should never use GL5 unless recommended by the manufacturer. There is some justification for that point of view, but I feel it does not apply to steering boxes and the Valvoline full synthetic (which does not use the "bad" "active-sulfur" additive).

 

[eschneider]

80/90. Regular cheap stuff is fine. The synthetic stuff (for a lighter steering feel) won't hurt anything if mixed. GL4 / GL5 - I agree with Randall, doesn't matter in this case.

 

[af3683]

Thanks to all. I happen to have some Castrol Hyploy C 80W90 which the container says is GL5. However, it is like 15 years old. Is this OK or should I get some Valvoline 80W90?or 75W90?, or the Valvoline fully synthetic 75W90?

Thanks,
Art

 

[TR3driver]

Should be fine. I like the full synthetic because I think it lowers steering effort slightly (and it's what I use in the differential), but it's not required by any means.

 

[big6]

Using GL5 lubricants in older gearboxes, differentials, steering boxes that have brass bushings, shims, synchronizers, and etcetera should not be used. GL5 lubricant will attacks brass parts causing premature failures. Therefore, in older applications GL4 lubricant is recommended.

 

[TR3driver]

Depends on which GL5 you're talking about. I've run the Valvoline full synthetic GL5 for 20 years and some 150,000 miles in my TR3A diff, with no ill effects. In fact, I credit it with making the diff (which was already well worn when it came to me) live so long.

The GL5 spec says nothing about oil composition, it's only a performance specification. There is a particular sulfur-based additive that some gear oils use to boost their performance, which can break down over time to form sulfuric acid that will attack copper and brass. Even some GL4 oils use this additive (it's the one that gives used gear oil that distinctive stink). But not all oils do.

The trick, I believe, is to look for an oil that is also rated MT-1. MT-1 says little or nothing about corrosion (it's for non-synchronized heavy duty transmissions), but has a long term stability requirement that the sulfur additive doesn't meet.

However, there is another problem with using GL-5 rated oils in synchronized transmissions. The synchronizers operate by friction, and most GL5 gear oils are too slick for good synchro operation.

 

[bigjones]

Uh, oh!

I've been using Castrol 20w-50 all these years. (Better than nothing I suppose)

Can I just top up in the future with Valvoline full synthetic 75W90 or is it best to drain out the steering box first?

Cheers!

 

[TR3driver]

Can I just top up in the future with Valvoline full synthetic 75W90 or is it best to drain out the steering box first?

My preference would be to drain and refill with gear oil. The box appears to need the EP protection (hence the factory recommendation for gear oil), and the additive packages are quite a bit different between motor oil and gear oil.

But most likely you won't be able to tell the difference.

 

[bigjones]

Fair dinkum, Randall. Thanks.

 

[sp53]

I use the Castrol 70/90 I think that is what they call it. The stuff is basically rear differential gear oil from Castrol. I like Don’s suggestion about using grease if the oil runs out, but I do like to follow the manufacture specs and use the gear oil. IMO I would not drain the steering box by loosening the four bolts because it might not seal back up. When I rebuild a box, I usually use Indian head shellac on the shim pack, so if I had to drain the box, I would loosen the olive fitting and drain most of it there and perhaps pop the cover or just keep pouring the oil through until I felt that the new stuff was pure enough. I might just pop the top and use a Turkey baster too.
Steve

 

[af3683]

sp53,

I think what you use is Castrol Syngear 75W-90 GL-5. There is also Castrol AP Gear 80W-90, not sure if it is GL-5 or something else. All gear oils seem to be GL-5. Haven't seen a GL-4 yet.

Art

 

[TR3driver]

All gear oils seem to be GL-5. Haven't seen a GL-4 yet.

It is getting rather hard to find. My FLAPS will sometimes have a gallon of it (Sta-Lube/CRC brand) but usually they only have GL-5 on the shelf.

However, TRF has GL-4 repackaged and sells it by the quart. P/N TRFGL4. Many other LBC vendors sell GL-4 as well, like British Pacific https://www.britishpacific.com/BPSite/LandRoverAccessories/Land_Rover_fluids.html

 

[Member 10617]

Now this is something I haven't paid much attention to because my steering is fine, but perhaps I should.

Following the Moss recommendation, I ordered Penrite Steering Box Lube and have been using it. But all along there has been a problem: the Penrite is so thick that only very small amounts can be forced down the hole (with the rubber plug) on the steering column. This seemed very strange to me, but "what do I know." So I have been pushing small amounts down the steering column whenever I thought about it.

After reading the previous postings, I have three questions:

(1) Should I stop using Penrite Steering Box Lube?

(2) Should I switch to one of the synthetic oils recommended in the postings?

(3) Can I mix one of the oils with the Steering Box Lube already in the box?

Once again -- I am having absolutely no difficulty with my steering, and there are no leaks.


BTW - Is there a difference between lubricating the steering box and lubricating the steering column through the hole on the steering column. I was under the impression that the steering box is lubricated through the hole on the steering column. That is what the manual says.

Confused and ready to be informed.

 

[Twosheds]

I would do #3 if I were you. That would be the easiest.

You can remove the plug in the unit and pour the oil in the hole, but I think it's easier to pull the rubber plug in the column and pour it in that hole. Unless that Penrite is blocking the oil from flowing down the column to the unit.

There is no lubrication for the column, only the unit (box).

As for synthetic vs. mineral-based, I don't think it makes too much of a difference.

 

[TR3driver]

As for synthetic vs. mineral-based, I don't think it makes too much of a difference.

I think you are probably right, John. I made way too many changes all at the same time to really say which ones produced the result. I replaced the bushing, peg and seal in the box; adjusted the box carefully (with a dial indicator); switched from conventional to synthetic gear oil; changed the original style silentblocs with free turning (and long life) brass/SS replacements; replaced and lubricated all the bushings in the steering column (including the felt at the steering wheel); disassembled, cleaned and lubricated the idler arm; aligned the box, column and idler arm carefully; and changed wheels & tires (to even wider than I was running before).

But the result was a dramatic difference in ease of steering. Before making those changes, I believed the popular wisdom that "All TR3s steer hard, due to cam and peg steering". Afterwards, it steered as easy as any manual steering car I've ever driven; and quite a bit easier than the Stag's power R&P when the power is out.

 

[Geo Hahn]

...I think it's easier to pull the rubber plug in the column and pour it in that hole. Unless that Penrite is blocking the oil from flowing down the column to the unit...

The Penrite is slow to flow (esp in chilly weather) but the process can be sped up a bit if the front end is raised off the ground and you work the steering wheel side to side as you add lube thru the rubber plug hole -- this seems to help the thick stuff find its way down the column.