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MG MGA - More poor quality replacement parts

I have just fitted a new replacement gearbox mounting bush to a MGA the O/S diameter of this new metalastic bush was so far out of spec you could not fit it even with a stick of dynamite, what is it with these parts suppliers, I for one would be happy to pay twice the price for good quality parts that fit,
Andy Tilney

The bush is meant to be an interference fit into the gearbox housing i.e. the OD is a thou or two greater than the hole diameter.

I bought one from Moss in 2005 and the OD was so much larger than the hole that I didn't even attempt to fit it. I returned it and bought one from Brown & Gammons. Even this was slightly oversize but no where near as bad as the Moss bush.

At the time I remember looking up the rules for an interference fit for the bush diameter and it was several thou over this.
But I gave it a try and put the bush in the deep freeze overnight and just before fitting I played a blow lamp over the gearbox for ten minutes.
Even so it was a very tight fit and I was concerned that the aluminium housing might split. Fortunately all went well.........................Mike






Mike Moore

It is an old problem that was supposed to have been fixed almost ten years ago. How old is your bushing? See here: http://mgaguru.com/mgtech/faulty/ft009.htm
barneymg

It was new last week, bought from the MGOC spares in the UK,
Andy Tilney

Can you measure the OD?
barneymg

Sorry no, I did measure the O/D of the bush and the inside diameter of the bush housing, but I did not keep these readings, and the car is now finished and is 40 miles away,
Andy Tilney

If it was actually possible to install the bushing, it may have been the correct size. These parts are supposed to be a very tight press fit, especially considering the large mating diameter. That is one part you really do not want to come loose.

To be cold fit a press or screw puller is preferred. Using a hammer, it requires minimally a two pound hammer. See here:
http://mgaguru.com/mgtech/gearbox/gt105.htm
http://mgaguru.com/mgtech/gearbox/gt105a.htm

If you can measure the part, the main body diameter (not the larger step at the end) should be 1.879" diameter (0.004" larger than the hole it mates with). Some time back (early 2007) some (faulty) parts were produced with 1.895" body diameter, having no chance of ever being assembled.
barneymg

I did manage to fit the bush, but only after I had turned down the O/D to the dimensions you posted of 1.879" I then used a screw type bush installing tool to press it in, as I said I did take both measurements, but after I had installed the bush I did not keep them, I know how tight these bushes should feel when installing them, and this one was to tight,
Andy Tilney

This thread was discussed between 23/02/2017 and 25/02/2017

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This thread is from the archive. The Live MG MGA BBS is active now.