Under the Bonnet: Steering System Lubrication

A question commonly asked of us is how to lubricate the later MGB steering racks, which do not have a lubrication nipple. In searching for a definitive answer, I discovered that lubrication of these later steering racks is not a scheduled maintenance item, and as such, there are no “factory” instructions for lubricating them in service.

The instructions for a new or newly rebuilt unit are to stand the unit on end and pour 4/10 of a U.S. pint of Extreme Pressure S.A.E. 90 oil in the gaiter. Apparently the factory felt that the initial lubrication was good enough to last “forever”, as long as the rubber gaiters were intact. In fact, the only time these later steering racks require additional lubrication is probably when the gaiters are replaced, preferably before they get ripped, torn, or otherwise damaged.

The best way to lubricate these is to remove the old gaiters, run the rack out to one side, by turning the steering wheel, and pour a bit of 90 E.P. oil along the exposed rack (dribbles and spills will drop onto the newspaper you placed underneath), run the rack out to the opposite side, and install the new gaiter. Repeat on the other side. If you want to get more serious about this operation, remove the pinion damper cover, shim(s), and damper housing. Slowly add oil while the steering gear is turned from side to side. Before reassembly, check the damper pad for wear, and replace if required. Re-shim if necessary.

Early MGBs with a lubrication nipple on the steering rack housing get 10 strokes of an oil gun charged with 90 E.P. every 12,000 miles or every 12 months, whichever comes first. (On all MGBs, the tie rod ends and swivel pins are greased.)

DO NOT FILL THE GAITERS FULL OF OIL! The purpose of the gaiters is not so much to keep oil in, as to keep water, dirt, and other contaminants out. A gaiter full of oil will split, squirt oil all over the place, and/or restrict steering movement. The steering rack needs only to be lubricated – it does not need to run in an oil bath.

The MGB lubrication question prompted investigation into steering system lubrication requirements of other British sports cars, a summary of which follows. “90 E.P.” and “140 E.P.” refer to the appropriate weight of Extreme Pressure hypoid gear lubricant, otherwise known as “gear oil”. Where grease is specified, a general purpose “chassis grease” is fine. If your grease gun is loaded with high temperature disc brake bearing grease, this will work just as well.

Before oiling or greasing lubrication nipples, wipe the nipples clean first, and ensure that the end of the grease or oil gun is also clean. Do not over-lubricate. If excess oil or grease gets all over everything, clean it up before it contaminates your brakes and attracts dirt.

For more details on the following, such as frequency of service, consult your workshop manual.

MG TC – steering box :140 E.P. to nipple on top of steering box-steering joints: grease

MG TD-TF- steering rack: 90 E.P. to nipple in center of rack housing under car-steering joints (tie rod ends, king pin links): 90 E.P.

MGA – steering rack: 90 E.P. to rack housing Si pinion shaft nipples-steering joints: grease

MGB – covered at beginning of this article

MG MIDGET – steering rack, through approx. 1972 – 90 E.P. to nipple-steering tack, from approx. 1973 – grease (remove hex- headed plug from damper cap, install grease nipple)-steering joints: grease

AUSTIN-HEALEY – steering box (all models): 90 E.P. thru filler plug in top of steering box housing-steering joints, 100-4: 140 E.P.-steering joints, Sprite, 100-6, 3000: grease

JAGUAR XK120 – steering box & idle lever: 140 E.P.-othcr steering joints: grease

JAGUAR XK140 – XK150 – steering box: grease in nipple in racK housing steering joints: grease

TR2 – TR3B – steering box: 90 E.P. – filler plug in steering column 12″ above steering box-steering joints: grease

TR4 – TR6 – steering rack: grease – replace hex head plug in pinion damper cap with grease nipple-steering joints: grease (except TR4A TR6 trunnions, which use 90 E.P. – sec notes at end of this article).

SPITFIRE – steering rack: grease steering joints: 90 E.P. on trunnions, grease elsewhere Supplemental notes for TR4A – TR6:

With the change in trunnion design introduced with the TR4A. Triumph apparently intended to change the lubrication requirement from grease to oil. The TR4A Owner’s Manual specifics oil, but the TR5 Workshop Manual Supplement, TR250 and 1969 TR6 Owner’s Manuals specify grease. TR6 Owner’s Manuals from 1970 specify oil. Triumph became aware of the confusion they had created, and in 1972 issued a Technical Service Bulletin stating that all then currently produced Triumph cars should use oil in their trunnions.

INSTALLING STEERING COUPLERS

The rubber steering couplers used in Triumphs and Jaguars (Moss part #667-390) are notoriously frustrating to install, as their hole spacing is larger than the hole spacing on the parts to which they mount. This is a design feature to ensure that when installed, the rubber is slightly compressed, thereby avoiding the possibility of looseness.

A quick and easy way to install these is to put a hose clamp around them, tightened to the point where the holes in the coupler match the holes on the steering column attachments. The mounting bolts are then easily inserted, after which the hose clamp should be removed. (If you do not have a 4″ hose clamp handy, open up two smaller ones and join them together.)

by Eric Wilhelm