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MG MGA - GROUND STRAP GEAR BOX
|Is the ground strap at the rear of the gear box the same as the one used at the engine mount? Where does the rear gear box ground strap attach? Will a second ground strap at the opposite engine mount suffice?|
Is there supposed to be an earth strap at the gearbox?
It does not show in the factory Service Parts List.
I cannot see what would be the purpose of a second earth in addition to the one at the engine mount.
The engine block and gearbox are one unit in electrical terms.
|M F Anderson|
|I have an issue with coils burning up, wearing the points shoe & quitting on the road. I have received advice from a very well known distributor rebuilder to install a second ground strap specificaly on the rear mount of the gear box. I have installed an electronic ignition in hopes of solving the coil issue but wanted to add the insurance of another ground strap. When I got under the car there was no obvous way to install a standard ground strap. I restored/rebuilt the MGA a few years ago & had assumed I missed the gear box strap.|
I too could find no refernce to a ground strap at the back of the gear box in the shop manual or in the Moss cataloge. Moss does not appear to sell a ground strap period.
Thanks for respopnding
|2K6167 is the Moss UK part number|
332-070 is the Moss US part number
This one bridges between the LH engine mount and chassis
There is no need to use a special MG part for this second one you want to install. If you get a standard earth strap for any car and connect it between the gearbox and the chassis it will do the job. I also don't see how it's going to solve your problem, but it's your car, so you know best.
I would suggest you should check the polarity of your coil connection, and flash the dynamo to make sure it is correctly polarised. Poor quality points that spend too much time closed because the heel wears away will overheat the coil, which is probably the cause of your original problems. The change to an electronic ignition will probably solve that problem, so you may not need the second strap in any case (and I have no idea why it has been recommended in the first place if the other one is properly installed).
I still can't figure out why an MG Midget horn push doesn't work because the steering column doesn't earth through the chassis mounted rack, even though everything is steel. But it really doesn't and just goes to show that the gods of Lucas sometimes do work in mysterious ways.
You do not mention whether your A is a 1500 or later model. I had a similar issue until I moved the coil on my '57 from on top of the generator to the fender where the 1600 coil is mounted. I also went for the Flamethrower fix and never had an issue with coil or points again.
|First, here is advice I received. it is the result of a detailed description of my problem a year or so back:|
" However, your failure of several coils tells me that you may have an engine grounding issue. I always suggest having at least 2 if not 3 ground straps from the engine ot tranny to the frame. Condenser failures also are common with a bad engine ground. The coils are a more ecommon problem. Many are coming from the same Chinese manufacturer and live short lives. Getting a good epoxy coil is cheap insurance! make sure whatever coil you have, it has at least 3 Ohms internal ballast (measured between the LT terminals) or you'll continue to have problems! "
I have effected all the suggestions except the grounding suggestion including moving the coil from the generator to the fender. I cannot readily see the left hand strap but it is probably the original from 1960. Who knows what condition it is in. The car, 1960 MGA, has been totaly restored, frame up, the motor is a later 1622 engine. My plan is to replace the original strap, add another to the right engine mount and buy & install one at the back of the gear box.
Thanks everybody for your help
|The only way adding a second or even third ground strap would make any difference, is if there is something wrong with the one in the factory installed location. Make sure it is in good condition, has clean metal to metal contact (not just at the strap, but also between the mount and the engine block).|
|If the ground is poor, the starter won't work!|
Even 0.1 ohm ground resistance will limit the starter action.
Who gave you the advice that you quoted?
This thread was discussed between 27/08/2014 and 28/08/2014
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