42 replies to this topic

[ls2lxhatch]

The replacement rack ends are designed for and come packed with grease.

The replacement passenger side bush is polyurethane so it does not really need any lube.

The bearings once packed with grease should stay packed. The top bearing may actually be better lubricated with grease than it would be relying on oil splash.

The rack teeth will hold grease so there should not be a problem there.

I expect that main thing that kills racks is lack of oil due to a damaged boot which is less of a problem with grease. I suspect that this is why many modern racks are lubricated with grease and I am yet to find a professional rack re-builder that uses oil.

Yet somehow I would still feel better if my rebuilt rack was filled with oil.

Edited by ls2lxhatch, 13 February 2012 - 11:40 AM.

[76lxhatch]

(I had this written out earlier but the site is on a goslow)

I'm no expert either.. ;-)


I don't know about lasting 30 years. With a ripped boot all the oil disappears pretty quick, a lot of the old racks I've removed were empty (but still working and apparently undamaged other than worn bushes, they're not really a high movement/high wear item I guess). Obviously grease is going to hang around a lot longer in this situation.


I guess there does need to be a little more clearance for grease to work but there is a bit there and we are talking about comparison with a relatively heavy weight oil which also requires suitable clearances. The rack shaft itself needs lubrication to slide at either end of the housing (at the bush and at the pinion) as well as lubrication for the gear mesh, and the inner tie rod ends. Personally I don't see any need for splash lubrication (not sure a 140 weight oil is light enough to splash in this application either), plus grease sticks to the surfaces rather than running away.


When people talk about 'packing' the grease in I don't think they actually mean that in the literal sense, even most wheel hubs shouldn't be fully/tightly packed. Because this is only a manual rack there aren't any seals other than the rack boots, so the hydraulic action is only caused by the seal provided by the lubricant, which makes it relatively easy to bypass. If the lubricant (oil or grease) gets pushed one way it can be pushed back the other - the boots collapse and expand in the right way to facilitate this movement. The only minor concern I can think of would be that if the grease is really thick and tightly packed then it won't move and one boot will balloon and the other will suck onto the inner tie rod end if they are properly sealed, potentially damaging them over time - you can see this with cheap/thin replacement boots using oil if you move the rack too quickly.


I don't know whether I'd prefer one option over the other, I've always used oil to date but can't see anything too wrong with the grease option if done correctly. If someone builds one with grease and is willing to back it up I don't see a problem.

[fuzzypumper]

I also used oil on my last two racks.

Maybe its the replacement bush being used which may very well decide whether you use oil or grease.

The original nylon bush was designed with circular inner and triangular outer which allowed the heavy oil to pass easily in and out of the boot
as the steering was turned through the 3 large outer holes.

The aftermarket replacements (eurothane) have a circular outer ( completely blocked) and use a hexagonal inner, which while makes it 6 holes,
but rather smaller to try push the heavy oil through.

Am I overthinking this or do I have my geometry wrong? maybe, but I still use oil as well.

Attached Files

•  Original bush rack housing(Small).JPG   39.52K   3 downloads
•  P1040598 (Small).JPG   54.12K   2 downloads

Edited by fuzzypumper, 13 February 2012 - 10:59 PM.

[Dr Terry]

I thought it was time that I added my bit here as well.

We mainly rebuild power steering racks, but manual racks still make up about 5% of the business, over 35+ years that's still a lot of racks.

The manufacturers of power steering racks mostly use grease to lubricate the non-hydraulic section of the rack & I've never seen issues with longevity. However I have seen many old style manual rack deemed unserviceable due to oil loss & wear or in bad cases, corrosion.

Over time the boots perish & leak & with the aid of underbonnet heat the oil will become thin & run out like water. The rack then has no lubrication & quickly wears the teeth. If the hole in the boot is large enough, it will be open to the elements & quickly corrode.

In the late 70s the only manual racks we saw were Toranas, Minis & Escorts & they all suffered the above problems, with every 2nd rack ending up in the bin. The quality of the rubber boots in the early 70s, wasn't that great either, especially on these Pommy racks. We changed over to grease soon after. We didn't just use any grease, we used high melting point (lithium base) wheel bearing grease. Because it's designed for tapered wheel bearings, no extra clearance is required, set-up & tolerances are all to factory spec.

We serial number every rack on completion & over many years you often get to those racks go back thru our system, even 20 & 30 years down the track. Even after that time the grease was still doing its job & these racks needed nothing more than a dismantle & inspection, maybe a bush or bearing & 2 new boots.

Nobody could convince me to go back to putting oil in manual steering racks.

Dr Terry

[Dr Terry]

To add to the above, the rack is not 'packed' or filled with grease. An adequate amount of grease is applied to the necessary mating surfaces including the left-hand bush, and no more than necessary.

Dr Terry

[EunUCh]

Dunno you guys sometimes,,ican see bothe sides of claims!
Grease wont run out if a rack boot gets a split but oil will flow between the moving parts
when steering wheel gets turned(even just out of a driveway is enough).
The way i see it we will just have to take our own run on what we do.
Some will use grease,,some will use oil.
Its up to us to take a look to see if any major oil leaks on pavement i spose.

[Dr Terry]

Grease wont run out if a rack boot gets a split but oil will flow between the moving parts

Its up to us to take a look to see if any major oil leaks on pavement i spose.

There is no 'flow' as such. The only parts of the rack which need lubricating are the meshing teeth, the left-hand end bush & to a minor extent, the pinion bearings, but they're not spinning that fast, are they.

This is part of the problem, the amount of oil in the rack is so small that as it weeps out over time; it will be a minor leak not a major leak & by that time the rack has been running dry for quite some time.

Dr Terry

[hanra]

Just overhauling my rack at the moment, its dated 7th 1975 so most likely original, but it was painted blue and had Fulcrum stickers on it, when I opened the boot, it had grease and a thick oil in there. Now that Ive stripped the blue paint off.... you guessed it.... maroon powder coat... F*ck Im so sick of that colour....

[EunUCh]

Now now Hanra,these things are sent to test us you know

[hanra]

Interesting quote I found on another forum:

I don't know anything about Cortina steering racks specifically, but I'm kind of a guru on Pantera racks, which are the same as used in the Ferrari 308 and many other period cars. They were made under license by Cam Gears UK--yes, they're British! Very similar racks were used in most British cars, and the GT40 rack vaguely resembles it so I suspect that might be a Cam Gears rack as well.

Originally, they were lubricated with 80/90W gear oil. That worked reasonably well so long as the oil actually stayed in the rack. But when the boots became compromised, the oil would leak out, then the rack would run dry and wear would be greatly accelerated.

I've rebuilt about 100 Pantera racks (most recently, one yesterday) and a couple of Ferrari racks. A particularly anal (in a great way!) friend of mine with a Ferrari 308 actually telephoned TRW, who purchased Cam Gears many years ago and continues to make their racks, and spoke with their tech department asking for advice on what to use to fill them.

The engineers there told him that using gear oil was a very old-school method, and that production cars have almost all switched to using a very lightweight and 'slippery' grease. He said to skip the gear oil and use O-weight grease instead (that's how their new racks are filled).

I searched high and low and couldn't find a reasonable source of O-weight grease (except in a 55-gallon drum, no thanks!). However, CRC engine assembly lube is rated at 0 to 1/2 weight, which is pretty damn close. The first 50 or so racks I rebuilt were filled with oil; after I learned about the grease I switched to this CRC engine assembly lube and have never looked back. It delivers a very smooth action, with the greatly added advantage of not ever leaking out.

Do NOT use traditional wheel bearing grease; that stuff is much too thick and sticky, and would lead to stiction in the steering.

[Hybrid]

I am considering converting my leaking rack from oil filled to greased filled. What was the answer to this question? Does the rack need to be fully dismantled to grease it up properly or can it be done by removing the rack boot?

 

I have a '73 4 door LJ, the steering boots have been replaced but I am pretty sure the oil wasn't, can oil or grease be added to the steering unit insitu or does it all have to come out? Is a grease nipple in the top cover plate better than oil?

[Hybrid]

One last bump. My leaky rack is still out of the car and I would love to know if I can grease it up effectively without fully dismantling it. All advice appreciated.

[76lxhatch]

I don't think it would be as effective, its really not much more work to dismantle it so that's the way I'd go