Recommended steering assembly lubrication

When I rebuilt mine, I did some research and actually was able to track down someone in England who had worked for CamGears, the company that made the steering racks. Historically, the recommended lube was about 5-1/2 ounces of 90 weight gear oil, but the rebuilt racks coming out had grease in them. I asked this gent about it and although he had left the company, he solicited a response from a colleague still working for them (now TRW). Here is the response:

START QUOTE
I left TRW Cam Gears many years ago but a former colleague has offered this bit if advice:

“Apparently oil has been used before for lubricating gear sets but not now. I believe we currently use Shell Sterak grease for the gear set but any multi purpose zero weight grease would be fine, but avoid using synthetic ones.”

Hope this helps!!
END QUOTE

So there it is from the folks who did and do make them... for what its worth. I found getting my hands on Shell Sterak a bit difficult, but I was able to find some 0/1 weight grease made by Sta-Lube at a local auto parts store. It seems to work very well.

Rick

 

"“Apparently oil has been used before for lubricating gear sets but not now." Spoken like a guy with no idea of what is really going on. He's just reading whatever the marketing folks say to read. He doesn't know anything about the subject. Saying "APPARENTLY oil has been used before..." pretty much says it all - he doesn't even know.

If oil is no longer used in gearsets they need to advise the world's tranny and differential manufacturers to quit using gear oil and start using grease. Put whatever Ferrari says to put in the steering gear.

 

Mike - Spoken like a guy who had never spent much time around Brits... the rest of his note was similarly, quite eloquently, British.

Ferrari didn't build the steering racks, they bought them from CamGears. Both these gents worked in their engineering department in that era. >>>There is quite a difference in load and rotational forces between a steering rack and tranny gears.



for Aaron... Sorry, I thought you were speaking of the rack itself, not the column joints. I'd hit them with something that will penetrate but that can be wiped off the surface or they will certainly draw dirt back in.

rick

 

LOL

Of course Ferrari didn't build the gearing racks but the people that did build them don't seem to know that they used to put oil in them. They put grease in them because it won't leak and you can have a bad seal with no oil dripping on the ground. This is not a better way to do it; it's an EASIER and "make it through warranty" way to do it. If a gear design/application should have oil, then it should have oil. If they changed the design or application THEN a change in lubricant may be appropriate. BUT to take a gear system that was designed to use oil and now use grease in it? Cmon!

 

Brits will often soften their statements with "apparently" and "it seems" because these qualifiers a) leave some room for other approaches and opinions, and b) this avoids sounding like an arrogant know-it-all. It shouldn't be interpreted as ignorance or lack of awareness, it's a just a cultural thing. If you've worked or lived in the UK, as I have, it becomes pretty second nature to use such conventions in speech.

 

I apologize for prolonging this thread and, with the information on how Britts communicate, perhaps my reading of the person's knowledge is in error. But regardless, IMHO, the "tech's" answer did not answer the question - I don't care what you put in a steering gear you make now - I don't have one of those, I have one you made in 1980-whatever. It seems to me that even in Brittspeak, the correct answer from an REAL tech would be: "We used to use X oil in the steering gear but modified [whatever internal parts] and now use grease" or, "We used to use X oil in the steering gear but we found that grease works fine in any unit."

As has been mentioned many times, what anybody does with their car is their business. So I will add only the following: First, I would not use grease instead of oil in this application because the steering gear was designed to use oil - it's not as if grease didn't exist at the time! Second, grease will increase the steering effort compared to oil.

It's good to remember that grease is used when oil would be thrown off the parts and not replaced. In any sealed unit - like a steering gear, transmission, engine, etc, this is not an issue and oil is the superior lubricant; grease is just oil in a carrier that makes it stick to things...

I promise I won't argue any more about this.

 

In a perfect world I would have to agree with you... but its rare that a product is put to market with no improvements down the road. By your logic none of us should be using improved oils in our gearboxes or motors... remember your steering rack has no seals other than the boots. Oil sloshes from side to side and can (read does) pool in the boots and not in the rack/pinion. Perhaps they found grease stays in the area needed better than the oil... Don't know (zero weight grease does flow). I just went to the trouble to track down (online resumes) some folks who worked for CamGears before TRW bought them . I asked a question, got an answer. Kevan even went out of his way for a total stranger to ask an old colleague for an answer. For that, I was greatful and shared. I have a buddy in the Pantera community (Pantera uses the same rack) who has rebuilt dozens of these racks at tech sessions. He has switched to using zero weight grease and says he has had great results. He also brought up that in the chance of an undetected split boot, you don't lose all the lube and run the rack dry.

I do stand firmly behind your conviction that this is your car and you should do whatever YOU want to. I will defend your position on that to anyone.

Rick

 

Oil is a great lubricant in many metal-on-metal bearing surfaces, both slip bearings and roller/needle/ball, provided it is distributed with a mechanical or pressurized means so the bearing surface runs in a continual bath. An oil sump is a mechanical means of distributing the oil (crank spins in the oil and sloshes it around) and an oil pump and passages is a pressurized means of distributing it. Oil is a very poor lubricant in the absence of a mechanical or pressurized means to redistribute it to the bearing surface. Grease, on the other hand, is a superior lubricant in these settings as it tends to stick to the bearing surfaces much better than does oil.

Oil works great in an engine because it is redistributed via mechanical and pressurized means and has a very low CoF. Grease works better in a steering rack because of the absence of an effective redistribution means.

 

I know I said I wouldn't argue but...

A steering gear box is lubricated by the components being somewhat (or totally) covered in oil - just like a transmission gearbox. There is no need for a pump of any sort. An engine, of course requires a pump because no rotating part of the engine is (or should be) actually immersed in oil.

I completely agree that a greased item will not immediately fail if a seal is defective. OTOH, a defective seal in an oiled unit is immediately apparent by the oil dripping. A blown seal on a greased item will let dirt in but will likely not let you know there is a problem until the damage is already done and manifesting itself by grinding/vibration/whatever.

 

Mike, two simple Q's for you:

1. Is the steering rack completely filled with oil? Also, does a rack distribute the oil in the same manner as a gear box?
2. Does an engine's crank throws not immerse in the sump oil?

 

I have never even looked at the steering gear in my Ferrari but I have disassembled other steering gears - rack and pinion and recirculating ball types. I have never seen any of them that used grease, only oil. That doesn't mean there aren't plenty around that do I guess. The problem with grease is that if the bearing mechanism uses bronze bushings, grease will not properly lubricate them because it cannot get into the interface between the shaft and the bushing. Using grease in such a unit will cause the unit to fail at some point due to lack of lubricant. NOT catastrophically but it will wear relatively rapidly and develop play that cannot be adjusted out.

No crankshaft on any modern engine ever rotates in oil. In fact, great steps are taken to ensure the crank has minimal "interaction" with the oil with the use of windage trays, etc. This is one of several advantages of dry sumps systems - no windage and subsequent lubrication and HP loss associated with it. Windage or, much worse, crankshaft contact is why a low oil level is not really a problem but a high oil level is. If the crank actually contacts the oil it whips it into froth and can cause the oil to be so full of air bubbles that the pump wont pick it up properly.

Additionally, even assuming the crank is clear of the oil, the wind generated by the crank can pick up a cloud of oil which actually impedes crankshaft movement and drops HP considerably. Mopar did tests on the Hemi in the 60s that showed a loss of 70-80 HP in a race hemi at 7000 RPM without a properly designed windage tray to keep that from happening. So running a quart or two low is far better than running a quart overfull.

 

I apologize for tracking down a couple of engineers who actually worked for the company that built the steering racks Ferrari used and getting their updated procedures. I should have never solicited feedback from people who are having success with those procedures.

By today's standards, we should just give you the Nobel Prize for steering racks now.

Aaron,
I hope you have your steering issue resolved and have many smooth and winding roads ahead of you!!

Rick

 

Actually that's three, but who's counting?
1. No. No.
2. Yes, it does not immerse, does not touch. A 1950's-design lawn mower engine might have a scoop on a crank throw to act as a crude oil pump, but any engine more sophisticated than that needs to have absolutely no crank-to-oil contact. Bad, very bad.

"In automotive parlance, windage refers to parasitic drag on the crankshaft caused by oil splashing out of the sump at high rpm. At 6,000 rpm, for example, the crankshaft must rotate 100 times per second. As the crankpins and counterweights rotate at such high speeds, they create a swirling cloud of air around them. Windage is considered to occur when excess oil is caught up in this turbulent air, drawing energy from the engine to spin the oil mist. Windage may also inhibit the migration of oil into the sump and back to the oil pump, creating lubrication problems. Some manufacturers and aftermarket vendors have developed special scrapers to remove excess oil from the counterweights, and windage screens to create a barrier between the crankshaft and oil sump."

 

I haven't disassembeld a steering rack, but in reading posts here about home-made steering rack bushings there was much discussion about oil passageways. Apparently the oil is circulated through the rack by the act of turning the steering wheel. Oil is moved through the tube much like air in a subway tunnel by a train. Is this positive pressure lubrication? Maybe not, but apparently it does move around in the rack and get on the important bits whenever the car is turned, it is not just sitting in the bottom of the tube.

 

"By today's standards, we should just give you the Nobel Prize for steering racks now."

I appreciate the award and am happy to accept! Thank you!

But I remain concerned that although you "tracked down" an "engineer" he failed to answer a SPECIFIC question..."If OIL used to be recommended in a circa 1980s gearbox, why is it no longer recommended for that SAME gearbox." I repeat what I said before - you have accepted an answer that did not answer the question at all.

Frankly, I would ask you THIS question, "Why do you want to put lubricant OTHER than what was specified for the specific component?" Do you put 140 wt oil in your engine? Why not? Because it's too thick for the application and won't lubricate nearly as well...just like grease in that steering gear.

All sarcasm aside, I'm really trying to help here but, as we have all noted, it's your car, put whatever you want in the steering gear.

Please ensure that Nobel is well packaged - sometimes shipping to Mexico can be a bit harsh.

 

I didn't have to ask that question, he offered that the reason. I just didn't post his entire letter. Never assume. The reason for change was a high failure rate. Probably not seen as often on exotics as they tend to be driven less than some of the every day cars that use the same rack. I later heard the Mini used the same rack, but i cannot confirm that. I would agree the average Mini was driven more than the average Ferrari.

This steering rack is hollow tube with enlarged ends. There are no seals on the rack. Let me repeat that, there are NO SEALS on the rack. (OK, there is a seal on the pinion gear shaft but that is on the top, not where any oil sloshes to.) There is easily 10mm or so of clearance between the rack and the housing at both ends. The oil sloshes from end to end with little or no objects to impede its flow. The only thing holding the oil in are the bellows at each end. If you hold a rack up and pour 5 ounces of oil into it, you'll have almost 5 ounces of oil fall out the other end. They found most of the oil was collecting in the bellows and not making it back where it needed to go. The result was racks running dry and binding on the slider block. The key here is they now recommend a ZERO weight grease... its consistency is somewhat like pancake syrup. It flows, it clings. We are not talking axle grease or wheel bearing grease here. If you order our racks as a factory remanufactured rack from TRW today it comes with this grease and a note to not add any lubricant. That is what started a friend to start this research and I jumped in to help. Since you haven't looked at your rack, here look at mine. Maybe it will help clear some things up.

http://www.flickr.com/photos/moseley_ferrari/sets/72157602899521527/

Rick

 

OK, I totally agree with you after reading the additional information that you posted. You are correct - I made an assumption - that "grease" referred to the type of grease that would be packed into a unit - like a wheel bearing. As you noted, 0 wt grease "flows" and is pretty much the consistency of heavy gear oils.

Sorry for the misunderstanding - I should have asked if you (he) was referring to something like 0 wt grease.

 

Hi Brian,

In case you weren't picking up my somewhat subtle approach, these were rhetorical questions....intended to point out inconsistencies in the logic being applied by Mike here.

Thanks for your answers however.

 

Cliff - I'm curious as to your perception of my lack of logic. I acknowledged my misunderstanding of the weight of grease being discussed and my subsequent agreement that I was wrong about the use of grease once I understood the specifics. But based on my initial (incorrect) assumption re using grease that would be "packed" into the system (again, like wheel bearing grease), I am not understanding your statement.

I'm really interested in understanding where I misapplied any logic and learn from the experience - whether it was from either my lack of knowledge or inability to properly express it in writing.

 

Hi Mike,

I'm not trying to atagonize, so please don't interpret my comments as anything other than collegial discussion around topics of common interest. My comments are technical in nature, specifically, I was responding to your indication that:

"A steering gear box is lubricated by the components being somewhat (or totally) covered in oil - just like a transmission gearbox. There is no need for a pump of any sort. An engine, of course requires a pump because no rotating part of the engine is (or should be) actually immersed in oil."

My two responsive points simply are:

1. A steering rack fundamentally differs from a gear box in the manner in which it is lubricated because a gear box has rapidly rotating assemblies that partially reside in an oil bath causing all of the interior of the gear box to be completely saturated in oil. A steering rack does not have this same (or any) mechanical means to repeatedly saturate all of the bearing surfaces, thus a partial oil bath is not very effective, unlike in a gearbox where it is highly effective.

2. An engine has a rotating crankshaft which typically has its throws immersed in oil at the lowest point (sump).

Was just trying to the above technical points - wasn't trying to be a know-it-all or offend in any way.

Best regards,

Cliff

 

Thanks Cliff

I also realize I was unclear describing the steering gearboxes that I have worked on. I have never seen one that wasn't filled with fluid (over the gears/shafts, etc), unlike a tranny which, as you noted, is normally "splash" lubed, with just enough fluid level to allow the gears to pick it up.