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MG MGB Technical - Loose cross member

After watching a John Twist video on You Tube that dramatically showed a loose front cross member, I've found the same condition on my 1970 MGB roadster.
I think one of the bolts has snapped, and it's probably time to replace the cross member pads as well as the bolts. Has anybody got any suggestions/tips to make this job easier?

Thanks,

Peter
Peter Van Syckle

Peter, according to the workshop manual you:-

jack up and support the front of the car and remove the wheels,
disconnect sway bar links from the spring pans,
remove steering rack (probably the hardest part of the job),
disconnect flexible brake hoses,
support cross member with a trolley jack at it's centre,
remove nuts and washers from tops of the support bolts,
lower the cross member and remove it from the car.

NOTE; the "bolts" are actually studs with a nut and washer on each end.

You may not have to go this far just to replace the rubber pads, it may be sufficient to lower the cross member just enough to slip the bolts out and replace the pads. You MAY not need to remove the rack or anything else in this case. If you choose to go this way make sure the brake hoses, sway bar links and steering arms are not stressed. However, as you are in the area you may want to remove the whole thing to give it a good clean and inspection. You also get to give the steering rack the once over.

As a bonus this also gives full access to the sump pan bolts so you can give them a bit of a tighten up or even change the gasket if you have leaks.


Cheers

Tony
Tony Oliver

Thanks, Mate.
Sounds like an off season job.

Peter
Peter Van Syckle

If you do actually have a cross member bolt missing (or snapped)) you mustn't drive it. It sounds like the front end is moving around so you should at least attempt to tighten it up and discover if you need to put a new bolt in. Imagine what would happen if , when you braked sharply, the remaining bolt came loose.
The nuts on the top end of the 4 bolts/studs are easy to get at. The nuts on the bottom of the rear studs are also easy to get at. The front bottom nuts are harder. Idealy you should take out the springs, however, it is quite possible to get a socket on them if you have a long socket extention. There are access holes in bottom the cross member just for that. It would be a very quick and easy job to tighted up the bolts. I replaced my pads with springs in situ. Did one side, then the other. That's a little more difficult because you have to balance the bolt in the socket and guide it back up through the hole. The back bolts are very easy to do.
You should also put some locktight on the threads. Use the very low strength, easy to get off grade. Blue in colour.
peter

Thanks, Peter.
I've always had a certain 'judder' going over rough roads. I've tried to tighten up the left side, and find that the bottom nut on the back bolt keeps turning, albeit on the end of a large breaker bar. That's why I think it's eiter broken or stripped.

Maybe the thing to do is to remove the top nut, and put some tubing over the end of the stud and let it drop through the bottom. I'd put the tube over the new stud and pull up through to the top. Make sense?


Best,

Peter
Peter

The tubing idea will not work, there is very little clearance around the bolt plus it has a shoulder on the bottom end that fits tightly into a female seat in the chassis support rails.

Clifton
Clifton Gordon

I doubt if it's broken, it would have dropped out. And its a huge bolt. Anyway, the back bolts are easy. With the front ones the spring prevents you getting your hand in there. Undo it and put a stack of washers in to get it onto some thread. Could be the nut is stripped and the thread on the stud/bolt is OK. You can't tell until you look. Or just go get a new bolt and nylox nuts can't be too expensive.
Because there is a nut on both the top and bottom (no idea why they did it that way) you've got to get a socket or spanner on both. You might need a helper, or some vice grips.

Peter

This thread was discussed between 07/08/2009 and 19/08/2009

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