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MG MGB Technical - steering oil seal replacement

Just finished all the work associated with replacing the gaitors on my 77 MGB. Filled with 90W oil, and now have realized I have a significant leak where the steering shaft enters the rack. Is there an easy way to change the oil seal with the steering assembly still in the car?
r schwartz

You will have to remove the universal joint. Either the steering column or the rack will have to be unbolted and moved some to provide enough room to remove the U joint. I don't know if there is enouch working room to change the seal with the rack in place. I would rather remove the rack if I had to do the job.

Clifton
Clifton Gordon

Thanks Clifton, read some more about this, and now I am thinking easiest way of replacing seal could be to unbolt pinion shaft from U joint, then unbolt rack end cap, and simply slide pinion shaft out through the end cap. Repace oil seal, and then slide shaft back through. That way I don't have to mess with dismantleing the tie rods. Is this doable?
r schwartz

It should work, although I've never tried it.

Clifton
Clifton Gordon

That method will work - it's exactly how I did mine.

I was worried about damaging the seal while sliding the splines through it on reassembly, so I cut some very thin plastic from a drinks bottle and curled it into a cylinder. Then I put that in the seal and pushed the shaft through it. It may have been unecessary but made me feel better.

Something else to consider is keeping the steering wheel alignment correct. Make sure you mark the shaft so you can put it back in the U-joint in the same place, and also be sure that the road wheels are in the same position when putting the shaft back as they were when taking it out. This is harder than it sounds because the shaft rotates as it comes out. I made a complete mess of mine and spent longer getting it right than it took to change the seal. On reflection it might work to have the steering at full lock and note exactly the steering wheel's position precisely before removing the shaft. Then put both in the same position before replacing it and keep trial fitting until the mark on the U-joint lines up right.

Oh, one other thing - I still found a persistent drip after I changed the seal. Eventually I realised that it was coming from the end cap bolts, so either use some thread sealer or ptfe tape when you replace them
Miles Banister

I can't help thinking it would be easier to remove the rack from the car and do the seal change on the bench. With all these lip seals it is important to get them in square and undamaged. A suitable working environment can only help that.
David Witham

Since this link was still alive, I figure I would update on progress. Replacing the seal with the rack in the car did prove too challenging, so rack is out of the car, the job really was relatively easy. I did remove the pinion from the rack though, and forgot to mark reference points for reassembly. Am I in trouble now?
r schwartz

Not a real big problem. Turn rack from lock to lock and count the turns, set it midway between the locked positions. mark the midway position in case something moves. Now center your steering wheel to the position it should for driving in a straight line. Assemble the rack to the column being careful to prevent the rack or steering wheel from turning. This should get you very close if carefully done. If it isn't off much I would adjust the tie rods to correct the problem. I'm talking maybe off an inch at the steering wheel. Any more it's best to remove the rack to make the correction. If the tie rods are adjusted too far off center you will have some undesirable steering problems.

Clifton
Clifton Gordon

Almost there, but not quite. I am in process of reinstalling rack, and having a real problem getting the pinion back into the U-joint. Just doesn't want to slide in. There were no washers under the rack, when I took it it out of the car, and the pinion lines up well with the U-Joint, but just doesn't go in. Any ideas certainly appreciated.
r schwartz

Both the steering column and the rack shaft splines *should* slide into the splines of the UJ at least as easily as they came out - unless one of the splined ends was damaged while things were off the car. You do have to look for notches and grooves in the shafts near the ends that make space for the clamping bolts. If one of the shafts has a notch (like the steering shaft on my 73 roadster) then the UJ will only fit onto this shaft in one position that allows the bolt to pass through. A shaft with a groove all the way round the shaft will assemble to the UJ in any position.

Even if the shafts are misaligned you can still move them laterally or vertically so they slot into the UJ, but unless they are correctly aligned this will result in rapid UJ and rack pinion bearing wear. There were special pointed caps that fitted over the end of the shafts to determine the shims for alignment, as a make-do I wind some stiff wire round the end of the shafts, with the free end the same distance from the middle of the groove or the notch as the centre of the spider is, then tweak the wire so that when you rotate the shafts the ends revolve at the same point in space i.e. don't wobble round in a circle.

I'm surprised there were no shims, it's possible, but the cross-member and its brackets would have to be in exactly the right place from the factory, which would be a real fluke. A PO may have lost or discarded them.
Paul Hunt 2

Thanks, I removed the U-joint to get a closer look, and sure enough the splines on the inside of the U-joint as well as the splines on the pinion were stripped. I think it may have been from me, not sure. Anyway, any recommendation what to do from her? Can I have the pinion splines and U-joint repaired at a machine shop, or should I buy a separate pinion shaft and U-joint, or last of all just buy a rebuilt steering rack and U-joint. Recommendations appreciated.
r schwartz

If they are stripped they should be replaced, you wouldn't want steering wheel to not steer the car. If you have a couple of nicks/burrs on the splines a set of small files can be used to dress the damage.

Clifton
Clifton Gordon

Stripped!? How on earth did you (or someone) do that? I can't imagine the force that would be required. If they really are stripped and not just a bit burred as Clifton suggests then on no account should you attempt to have them repaired for safety reasons, replacement is the only option. If you replace the rack, and probably best if you replace the rack shaft as well, would be to do a proper alignment check and shimming before fitting the UJ.
Paul Hunt 2

Thanks all for your help. This board helps me immensely,and I certainly appreicate the time you put in to provide advise. For what it's worth I'll report back. I tried to remove the steering pinion shaft with the rack in place, a shortcut. It's obvious now, but at the time I didn't know that the pinion was splined, and I tried to turn it in the U-joint, buggering up the splines. After Paul's suggestion that the splines may be just burred, I took both U-joint and pinion to a machine shop and for 15$ they cleaned up the burrs.
So I am ready to reinstall again. Bottom line, if I were to do this again, I would take the steering rack off the car. Anyway thanks to Cliff, Paul, and others for seeing me through this.
r schwartz

This thread was discussed between 09/07/2006 and 31/07/2006

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