MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Gearbox mounting help


Whilst preparing to install a new fuel tank, I noticed that one of the bolts that hold the rear gearbox mount was lose.

Not sure yet if this is due to stripped thread or captive nut coming free and rotating with bolt.
If the former I can tap a new thread in a larger diameter.
If the nut is lose, is there any alternative to cutting a hole in the car floor above to get access?
Thanks
Vic

V Todman

Do you mean these?

http://www.youtube.com/watch?v=gUJE0AkWh1E
Steven Devine

I don't think it will be a loose nut because from memory the holes are tapped through the leg into a metal bar which is long enough for both set screws. If the set screw won't tighten the I think it is a simple matter of drilling and tapping out to a larger size.
Iain MacKintosh

Thanks Gentlemen.
Steven - I always find John Twist's videos very helpful [ esp. " how to fold your hood' ]. The bolt I am having problems with goes through a hole in the part of the mount that connects to the chassis. John points to them at the start of 6th minute.
Ian - I 'd hoped the answer might be something like this. I'd just decided to stop for the evening, the point where one always finds a problem and didn't want to start without advice.
Buying a converted car is always a bit of a lottery, presumably the screw had been slightly loose with the head gummed in with underseal since 1992.
Thanks again
Vic
V Todman

There is a threaded plate inside the chassis section. Sometimes the thread can strip.
What I have done is to drill 5/16 drill straight through and into the car, ie through the floor. Open up the hole in the floor to take a piece of tube the size of the chassis rail. A long bolt with a large washer on the inside and bolt it all the way through. The tube is needed to stop the floor pulling in.

The other thing I have done is to cut a hole in the floor to get into the chassis rail and drop a new threaded bar in. Make a nice new plate to cover the hole.

Job's a gudun!!

CP
Colin Parkinson

If your problem is with this mount (see photo) then you will need to loosen the two rubber pads then attach the four screws to the tranie. Then tighten everything up before attaching the cross plate to the chassis.

David Werblow

Sorry did not reply sooner, took a few days off for Easter.
David, luckily, the problem screw secures the outer part of the mounting to the chassis. Colin, I thought I might have to do as you recommend, but did not want to get distracted, so have tapped hole to 7/16" for the moment.
Thanks for your advice
V Todman

This thread was discussed between 24/03/2013 and 02/04/2013

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now