MG-Cars.info

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

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 - BGT Rear axle cover

One of the bits that I have been unable to get off to check as part of servicing is the level plug on the diff. It is pretty corroded and despite some brute fore and several tools I have been unable to remove it.
The plugs is fairly week looking and is starting to twist with the attempts.
The easiest solution would be to change the whole rear cover and put a new plug in.
Having trawled internet I can find new ones in the US but they want about £70 plus shipping.
Anybody have a spare one lying about that that would be willing to part with for a few quid.
Its either that or buying a whole axle for the rear plate.
Neckieman

I've had to chisel mine out in the past, and replaced with one with a hex socket. These have the same part number (6K499) as the originals, so you would have to check which type your chosen supplier has.

For a rear cover try Andy Jennings and Welsh MG.
paulh4

I am going to Wrexham in 5 weeks anyway so if I could get one this was my back up option.
Neckieman

Neck.
If you are going to remove the plate, you could drill the bung out. depending on how good a shot you are with the drill, there might not even be a need to retap the thread-
New hex headed bung and all fixed--
Diff bungs regularly get overtightened for some reason, they don't hold the wheels on and only need to be just tight, not tweeked right up
willy
William Revit

I always found a good clean of the area then the patient use of a good penetrating/releasing fluid (like PlusGas, not WD40) seem to do the trick, put plenty on and leave overnight, repeat if required.

Would it be possible to weld in or on a sacrificial socket or socket bar and covering any splits on the plug (or am I dreaming again?). That with the use of PlusGas and a lever arm of some sort would give plenty of purchase.

I’ve got a feeling I got away with wedging a torque bar type wrench in a plug with a split starting and just used the direct leverage from that to loosen the plug (after soaking with PlusGas), best to have the car well secured though if raised.

You might also try Dave O'Niell of this parish for a cover plate too.
Nigel Atkins

Thanks for the plug, Nigel, but I don't have any Salisbury axle parts.
Dave O'Neill 2

Do you guys have Loctite products over there
Their 'Freeze and release" pressure pack would do it- give the bung a good old spray and it will screw out as easy as
There is one the same, but cheaper that I use called Freeze It, but I can't find a brand name on the can only freeze it
worth a try

William Revit

Welding the head and short piece of shank of suitably sized bolt into the plug occurred to me also, in fact that is what I did (with the plug out!) before I discovered the hex plugs.

However unless the return path for an electric welder is elsewhere on the plug, and not the cover, you may end up welding the plug into the cover.
paulh4

As you can tell Paul I know nuffink about welding.

Many years ago I used a shock & release spray but found it no good - however that was many years ago and it might have been a cheap rubbish one, there seem to be many on offer now and they might be more effective than the one I tried (it might have been (Halfords?) Shock and Unlock but with a different name then or I might have remembered wrong).

Given enough time and enough soakings I've always found PlusGas (well Rapideeze before that) works very well, and I always try to tighten first before trying to undo to try to crack the rust/muck/crud seal.
Nigel Atkins

I find that a good hard smack with a club hammer usually does the trick....
Chris at Octarine Services

A trick I have used many times for broken studs and I dare say would work on a bung is to use a stick electric welder. A mig doesnt work due to it not able to transfer enough heat. Use a tacking technique and build up steel until you can get hold of it with visegrips or the equivelent. A 3.2 rod seems to be the best. The welder is able to localise the heat. If you have done any welding you will know that a weld always pulls to the side it is welded on. This is because it shrinks the steel it is aplied to after the welding. Let it cool properly to get maximum shrinkage before trying to remove. Have removed down to 8mm studs using this method. It does sound drastic but has always worked for me.
Rod
R J Pemberton

Plusgas is a bit specialist now, probably because it works and has been frowned-upon. A home-brew I used many years ago was a mix of Diesel and Oildag (colloidal graphite in oil, something we used at work but probably even more specialist) - the Diesel as that will seek out any crevices, and the oildag for lubrication. Shock and Unlock didn't seem to help at all at first, although several applications a couple of minutes apart and left to soak in may be better. For the axle cover it would probably be better if it were removed and laying on a horizontal surface for any of these liquid penetrants, even given capillary action.
paulh4

PlusGas is made by a different company now that seem to say it's the same stuff as before. It's freely available on t'web (and Euro Car Parts stores(?)), I bought a spray can very recently to supplement my drip can (it's now with a black label rather than the previous blue - even if the seller shows the old can as I found).

http://www.plusgas.co.uk/

Nigel Atkins

A 50/50 mixture of Automatic Transmission Fluid and Acetone works at least twice as well as the best commercially-available penetrating fluids. Cheap to make, too.
Stephen Strange

Someone's been watching The Repair Shop? :o)
paulh4

I eventually got it out by drilling it, trying an easyout which did nothing, using a dremel to grind it out to the threads and then eventually hacksawing and using a chisel.
I didn't damage any of the threads and I have new hex plugs to put back in.
There was no corrosion, the plug and cover threads are prefect and I can omly assume that someone jumped on a bar to tighten it so hard there was no way it was coming out bearing in mind the rubbish condition of the square key hole.
All well that ends well, it was just a job as part of my tidy up that did nothing to improve the car, just enabled me to get in and check the axle oil level now and in the future!
Neckieman

This thread was discussed between 20/03/2018 and 05/04/2018

MG MGB Technical index

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