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MG MGB Technical - REPLACE STEERING RACK

I am replacing the steering rack on my 74 1/2 MGB. The old one is out. I did not take off the upper part of the U joint at the the steering column (I sliped the pinion down and out. The new rack, and when I attempt to put the old one back in go, into the U joint too far. I cannot get the mounting holes far enough back to bolt the steering rack in place. The mounting shims are in place. Could the steering column have move down?? Is there some kind of spring that would move the steering column/shaft down??
William Webb

Is this a Chrome bumper car? I think I picture what you mean - that it seems the UJ has moved further down out of the cone panel?

You have renewed the rack - the horizontal bit with the gaiters etc, but still using the original pinion shaft. Is that correct?

The lower part of the column on mine, before it leaves the cockpit and joins onto the UJ, slides in and out of the upper part because the internal plastic 'lugs' have been popped off at some point in the past. I think they are designed to do that in case of an accident to alow the whole thing to collapse perhaps?

Since the lower mounting point under dash fixes to the outer (upper part) of the column it is possible that the inner (lower) part of the column in your case snapped its internal lugs and has slid out/down.

Have you tried pushing it back in!

Liam

It is a rubber bumper MGB. Yes, I am replacing the horizontal rack with the gaiters - the new rack also has the pinion. The idea of the steering column slipping down is very interesting - can I just push it back up?? I did try pushing by having the steering rack with the pinion in the U joint and pushing on the bottom of the rack to line-up the four mounting holes but this did not work. I tried, with the rack off, pushing the steering column up (toward the rear of the car) but there is not much to put a "prybar" onto to exert any force.
William Webb

I would imagine that if it needed a crowbar to move it then it probably isn't going to solve the problem.

I have had a look at my spare - it is spring loaded and under some pressure, just above the UJ is a circlip holding the 'end' on, behind which is a spring. If you have damaged that circlip the whole lot might slip down and it might cause what you describe.

If you have left the top column in situ this would be hard to see.

There are some simpler ones as well -

You didn't put the pinch bolt back in the UJ for safe keeping and forget it was there when trying to get the pinion shaft back in?

The upper part of the UJ hasnt moved down the column shaft at all?

Is the new pinion shaft the same length as the old one, and have you tried fitting the old shaft to the new rack? It wouldnt be the first time someone was supplied with a chrome part for a rubber car, esp as yours was made around the time of the changeover.

Liam
Liam

The spring and circlip sounds probable. The pinch bolt is old, both the old and the new streering racks do not go in far enough, the new rack is for the 74 1/2 - 1980 (rubber bumper) and measures the same distance.
I can force the column back about a 1/4 inch by prying on the rack but not enough to line-up the mounting bolts.
The MOSS blow-up does not show a circlip or spring. The Haynes manual does mention an energy absorbing tyoe of steering column, but I am stuck on how to push, and hold, the steering column back far enough.
William Webb

I haven't replaced a rack on rubber bumper cars, but have replaced a couple of racks on chrome bumper cars. All MGB from 1968 model year on had energy absorbing steering columns. The columns changed with the rubber bumper cars, it was still energy absorbing. When removing the rack the universal joint is usually difficult to remove if it hasn't been removed since new. It takes some prying and pulling to separate the u-joint from the rack. In the process of removal the lower section of the collapsible column will sometimes get pulled down. Remove the u-joint from the column and try driving the column in with a soft hammer, this works on a chrome bumper rack. The chrome bumper column has a spring at the bottom, but it isn't strong enough to pull the shaft out without some help.

The lower section of the column has a flat area about 5/8" long so the steering rac can be moved for fitting. The top pinch bolt sould be left loose enough to position the rack.

Getting your steering wheel straight will be much easier if you remove the u-joint at the top. Turn the steering wheel to the straight ahead position. Note where the flat is located, As I recall it will be at the top. Next turn the steering rack from lock to lock and carefully count the turns. Set the rack midway between the the lock to lock limits. Slip the u-joint on the rack pinion shaft so the pinch bolt in the top of the u-joint will align with the column flat. Install the rack leaving the u-joint pinch bolts loose until the rack is mounted.

The above paragraph assumes the rack to column alignment has been verified with some type of alignment pointers prior to installing the u-joint.

Clifton
Clifton Gordon

Sounds like you might have to take the upper column off anyway - its only a 5 minute job.

If u need a pic off what the end of the RB column with the circlip etc looks like out of the car let mre know.
Liam

A picture of any part of the steering column would be helpful. Thank you.
I do not understrand how the energy-absorbing works and will start a new thread asking about it.
William Webb

This thread was discussed between 15/04/2006 and 16/04/2006

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