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MG MGB Technical - Cold feet
On a run last weekend I noticed a really cold blast of air around my feet and legs even though the heater was on and working. When looking for where this draught could be coming from I noticed a biggish gap around where the steering column comes through the bulkhead. Should there be some gaiter or whatever there to close this gap. 71 roadster. Thanks |
Trevor Harvey |
You should have one of these https://rimmerbros.com/Item--i-AHA5435
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Mike Howlett |
Which side were you looking from? That gaiter is on the cabin side, 'C' in the attached. Also check the cold-air flap (lever in the passenger footwell) isn't open. |
paulh4 |
Yes that looks like that is missing from my car, So would that be fitted by disconnecting the UJs joint and which way round should it go,( bulk of it inside or outside of car). Thanks |
Trevor Harvey |
The bulk of the seal is inside the car, at least it is on my 1969 car. I suppose the bellows part could be squashed through from under the bonnet once the inner column is disconnected from the UJ. The upper end in the Rimmers photo has a pair of lips that sandwich the metal of the bulkhead and it's just that end that is visible in the engine bay.
If you unbolt the upper part of the UJ you may be able to pull the inner column further into the car, possibly enough to slip the seal over the shaft. Carefully mark the column and the UJ so that you reassemble onto the exact same spline. I'm assuming your '71 UK car doesn't have the collapsible column. My '71 didn't have one. |
Mike Howlett |
Yes inside as per the image I posted, with the 'straight' part sticking through the bulkhead into the engine compartment.
If you have a steering lock (only legally required in the UK from 1st Jan 71) you probably won't be able to withdraw the inner shaft far enough with the outer still mounted to fit the gaiter as the bulge in that shaft for the lock prevents it. You can't even pull it back far enough to remove the UJ without pulling the rack forwards. No lock and the shaft should pull straight out. It's not difficult to remove the column complete but you will lose the alignment for the UJ and it will be important to get that right. Google 'MGB column alignment gauges' for sources. Some show different gauges for CB and RB but Moss for example do both by having two screw holes for the different UJ lengths. Both upper and lower clamps on the CB columns allow for vertical alignment, the lower clamp also allows for horizontal alignment but if you don't slacken the bolts on the heater shelf by the oil gauge connector (not needed to remove the column) you won't upset that. Always assuming it is correct now of course. Bear in mind that the intermediate shaft used from 70 to 75 is collapsible and you can shear the nylon pegs if you are too violent with it, then you can pull the upper part of the inner and the wheel towards you! Also bear in mind that it is the column outer in the clamps that determines the alignment of the steering wheel to the column cowl as it can be slid through them. So it is a case of getting that 'fore and aft' alignment correct before down the 'up and down'. If you put paint marks where the clamps meet the tube before slackening the bolts that should be enough. |
paulh4 |
Paul, you make it sound quite a job, yes mine has steering lock. I haven’t got the gaiter yet but do you think it’s possible to cut down the length of the gaiter to make it fit without disassembling and glue it to Gether afterwards as I assume the gaiter is there purely as a draught excluder. |
Trevor Harvey |
Yes it is just a draught excluder. If cutting and gluing 'works' for CV joint boots then I'm pretty sure it will work for this, especially as once in there it just sits between the outer and the bulkhead i.e. no rotation. Subject to feet kicking it and the inner having clearance to the hole all round. However mine is plastic and pretty rigid which would be awkward to fit in the depth of the footwell, can't tell from Rimmer's picture if that is plastic or rubber. But anything should be better than nothing, and a couple of cable-ties just snugged up round the corrugations should pull the edges together. In fact plastic probably would be better in that respect rather than flexible rubber. |
paulh4 |
Thanks for your reply Paul. I had only looked at this from under the bonnet and could only see the gap around the shaft. On a closer look from inside the car I can see the gaiter is there but it's to far away from the bulkhead to close the gap. The splines are showing on the steering shaft where it goes into the UJ so I assume it is not in far enough, if this is loosened and the two clamps holding the steering wheel shaft is also loosened then pushed forwards this might close the gap making the gaiter close the gap. |
Trevor Harvey |
The clamp bolts on the UJ are supposed to pass through a cut-out or a notch on the two shafts otherwise it would be possible for them to be pulled apart. There would be a lot of spline showing if it were not fully engaged, see the column side (left) of the first attached (the lower UJ is just comparing lengths of CB and RB)
On the other (rack) half, between the yoke and the clamp bolt, looking through the gap you can see the shaft splines go past the clamp bolt, by turning the wheel you should be able to see that on both halves of the UJ. Which leaves the question of why the gaiter isn't sandwiched between the column outer and the bulkhead. That can happen if the outer is clamped too far away from the bulkhead, but by itself that would push the cowl up against the wheel. Do you have an after-market wheel? |
paulh4 |
Yes it has a Motolitre steering wheel. The gaiter is a plastic one and the small end did not protrude through the hole, it was clamped to the steering shaft with a jubilee type clamp, I have managed to work it further down the shaft and now if not a perfect fit it’s a much better fit than it was and I’m happy to settle for that . Thanks for your advice. |
Trevor Harvey |
I had imagined it butted up against the end of the outer so as to compress the bellows against the bulkhead, with the narrower end through it, to make the seal. However opinion elsewhere is that it goes the other way round with the narrow end inside the outer and the big end pressed against the bulkhead not passing through it, and that is how both Haynes and the Leyland Parts Catalogue show it. That makes more sense as that _would_ compress the bellows and it wouldn't slide up the tube.
However ... the one on my 73 is completely different to AHA5435. The part changed at chassis number 258001 to BHH 531 which is much longer, as pictured. The left-hand end fits over the outer with the step preventing it going too far, and the narrower part at the right-hand end does pass through the bulkhead. That was in Aug 71 for the 72 model year along with the change from 'solid' to collapsible column, steering locks came in before that. Every day a school day. |
paulh4 |
This thread was discussed between 16/10/2024 and 19/10/2024
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