I have just done some mods to to the Cortina Steering rack in in my GT40 and curious as to what oil or grease should be in it.
Some of the parts had grease on and there was also a heavy oil floating around in there so I'm not sure what to think.
I have just modified the ends of the rack to use different rack-ends as the Cortina ones are too short and I dont like the use of male - female extenders.
Also the Cortina rack-ends are orphans in that there is no other rack ends that will fit wwhich are longer.
I have an RF and I have just had to fill my steering rack after the original oil that was in there leaked out. I looked into it a bit on this and other forums and come up with 80W/90 gear oil. About 250 mill seemed to do it.
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.
Your mileage may vary....
Mike Drew, Vacaville, CA ( To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. )
'72 De Tomaso Pantera, '66 Contemporary 427 Cobra, '66 Shelby GT-350 clone, and gearing up for a Superformance Mk 1....
I'm using the same rack in my RF as well, with additional mods though.
I can try and scan the factory manual for the repair of the rack.
In a nut shell.
- Pinion bearing requires a 0.13mm shim for preload (after the bearing spacing is level with the housing, including gasket)
- Rack slipper bearing requires a gap of 0.05 to 0.12mm between the slipper bearing and cover plate (spring preloads it)
- Torque required to start the pinion rotating should be between 565 to 1700 mNm.
- Lubricant capacity 0.20 litres of SAE 140 EP oil.
The info you supplied is probabaly all I need to set it up
In case you were wondering about the mods I did, I have machined off the ends of the rack and drilled and tapped the rack for 16 X 1.5 mm Rack-ends as this seemd to be the most common size. I then used Ford Territory rackends and tie rod ends. The main reason for doing this was I was not keen on extensions to make the rack long enough.
The only thing ineed to do now is create a 7 degree taper in the arms I have.
I though about doing it in my mill-drill by holding it in the dividing offset by 3.5 degrees but cant get a full rotation so looks like I will mount it in the lathe by tacking it to a bit of round bar and boring it.
Since I am starting with unmachined arms I decided to put the tie rod ends in from the top of the arm which will let me move the rack up a little further and keep it out of the way of the pedals. Unfortunately i will have to go through the hassle of checking the bump steer etc.
I had to extend the width of the pivot points (~2" per side) to help with bump steer. Factory RF's used an earlier model rack which was wider.
I also raised the rack the same way as yours and rotated it to get the input much higher (to clear the pedals).
Moved it ~2" rearwards to increase Ackermann.
Old picture to give you an idea.