9 replies to this topic

[mk=john]

Hi
I would like to re-use my Mk1 steering rack, as part of my restoration. I am aware that I cannot get a refubished Mk1 steering rack. The one I have was working OK when i removed if from the car.

Everything is tripped from the car, including subbys, and the next thing to go back is the steering rack.

What is the least I should do service wise to my current rack, knowing that refurbished units are not available? if i were to relubricate it, is it just a matter of removing the gaiters and filling with new oil? What type of oil is recommended?

I have a new Mk2 steering rack but don't want to use it if this Mk1 rack is still good.
Any advice would be great.

Thanks
John

[bmcecosse]

Grease is specified for the Mini rack - I use Moly grease.

[tommy13]

I have a genuine BMC manual from the period which specifies EP 140 I think the capacity is 1/3 pint, but I can't be sure on the capacity as I cant find said manual at the moment.
A later SP manual I have specifies EP 90 (0.2 litres 0.3 pints)
These eary racks have a felt bush in the end opposite the pinion, which I assume is similar to the lower column bush in terms of material, and would possibly be better lubricated with oil. Grease is generally specified for all later racks.

Edited by tommy13, 24 April 2010 - 05:18 PM.

[bmcecosse]

Oil just runs out into the bellows - leaves the rack to wear away unlubricated. Use Moly grease - it will be fine.

[dklawson]

This is an area where oil is in better than grease. I have acquaintances in OZ who have found exactly the opposite of what you'd think to be true. They have found that grease is pushed out of the contact area leaving little or no lubrication on the rack and pinion... requiring racks run with grease to need more frequent maintenance and rebuild. Oil, even in the convoluted bellows, sloshes around and finds its way back to the gear teeth and the rubbing surfaces of the rack. However, oil does tend to leak out... all at once if you have a tear in the bellows.

John, Tommy already suggested what I was going to point you towards. The felt bush on the off side will likely have perished. The bush is important as a "clunk" dampener. Without it, you'll hear a periodic "clunk" from the front end when you hit bumps in the road. The felt is NLA and the later plastic bushes don't fit. However, there is a work around. I believe the rack is 11/16" outside diameter (measure yours to be sure). If you have a hydraulic specialist near you (hoses, cylinders, etc.) buy a short length of hydraulic hose close to that inside diameter... larger if necessary, not smaller. When you remove the gaiter and crank the rack all the way to the off side, you'll be able to remove the retaining screw and rig up a hook to pull the metal collar out. The metal collar "used" to retain the felt. Cut a short length of the hydraulic hose, perhaps about 1/2" long. Cut a split in it so you can wrap it around the rack. Sand down the outside diameter of the hose as necessary to fit just inside the metal collar you pulled out. Finally... take a file or disk grinder if you have one and cut some axial slots along the outside diameter of the hose. You want it to look sort of like the splines on a primary gear. Those slots allow the oil to work its way from the bellows back along the inside of the rack. Don't forget them. Finally put the hose in the rack followed by the metal collar and the collar retaining screw. Before tightening the bellows clamps to the rack add the oil and you'll be ready to reinstall it on the car.

[mk=john]

This is an area where oil is in better than grease. I have acquaintances in OZ who have found exactly the opposite of what you'd think to be true. They have found that grease is pushed out of the contact area leaving little or no lubrication on the rack and pinion... requiring racks run with grease to need more frequent maintenance and rebuild. Oil, even in the convoluted bellows, sloshes around and finds its way back to the gear teeth and the rubbing surfaces of the rack. However, oil does tend to leak out... all at once if you have a tear in the bellows.

John, Tommy already suggested what I was going to point you towards. The felt bush on the off side will likely have perished. The bush is important as a "clunk" dampener. Without it, you'll hear a periodic "clunk" from the front end when you hit bumps in the road. The felt is NLA and the later plastic bushes don't fit. However, there is a work around. I believe the rack is 11/16" outside diameter (measure yours to be sure). If you have a hydraulic specialist near you (hoses, cylinders, etc.) buy a short length of hydraulic hose close to that inside diameter... larger if necessary, not smaller. When you remove the gaiter and crank the rack all the way to the off side, you'll be able to remove the retaining screw and rig up a hook to pull the metal collar out. The metal collar "used" to retain the felt. Cut a short length of the hydraulic hose, perhaps about 1/2" long. Cut a split in it so you can wrap it around the rack. Sand down the outside diameter of the hose as necessary to fit just inside the metal collar you pulled out. Finally... take a file or disk grinder if you have one and cut some axial slots along the outside diameter of the hose. You want it to look sort of like the splines on a primary gear. Those slots allow the oil to work its way from the bellows back along the inside of the rack. Don't forget them. Finally put the hose in the rack followed by the metal collar and the collar retaining screw. Before tightening the bellows clamps to the rack add the oil and you'll be ready to reinstall it on the car.

Hi Doug
Thanks for the information. I have a new Mk2 rack, would it be wiser to use that instead, considering the turning circle is improved?
Thanks

[bmcecosse]

If you do - you must use the matching steering arms - not the Mk I arms!

[Mei]

If you do - you must use the matching steering arms - not the Mk I arms!

why...

[dklawson]

If you do - you must use the matching steering arms - not the Mk I arms!

why...

Because if you don't use the right arms on the hub the car won't have the proper front end geometry and alignment. The racks are a different length and using the Mk2 arms with the Mk2 rack maintains the "proper" geometry.

John, it's a matter of personal choice. However, I have a good condition used Mk2 rack and arms in the attic to use when I am next faced with rack maintenance. I won't hesitate to fit the Mk2 rack on my Mk1. It's not something that anyone would notice through appearance.

[mk=john]

If you do - you must use the matching steering arms - not the Mk I arms!

why...

Because if you don't use the right arms on the hub the car won't have the proper front end geometry and alignment. The racks are a different length and using the Mk2 arms with the Mk2 rack maintains the "proper" geometry.

John, it's a matter of personal choice. However, I have a good condition used Mk2 rack and arms in the attic to use when I am next faced with rack maintenance. I won't hesitate to fit the Mk2 rack on my Mk1. It's not something that anyone would notice through appearance.

Hi Doug
Well, since refurbished or serviceability Mk1 racks is not possible at this moment in time, i have decided to install the Mk2 rack instead. It is a new rack however, not a reconditioned one. Anyway, I guess the rack is better anyway due to the tighter turning circle, and also will not give me any problems hopefully for many years.

However, i am a stickler for originality, so if one day refurbiched MK1 racks are available i may even be tempted to put a Mk1 rack back on the car.
But for now, its going to be Mk2. I also have Mk2 cooper S steering arms.
As said, no one will notice these items even in concours.

John