I tried to change the oil last weekend, but was thwarted by an unremovable sump plug. On closer inspection, there are two dints in the bottom of the sump, so I'm guessing the threads for the plug have become tightly deformed.
It's a rover v8, with a huge (29mm?) hexagonal plug. I have 28mm and
Is this something that can be fixed without removing the sump?
You should be able to buy a pump from any decent Chandlery that will let you drain the sump via the dip stick hole.
sPONiX
I have always found a hammer & chisel work for me in this situation!
Um, have you actually *tried* with the correct size tool? Forget spanners, use a socket with a decent length bar. It's difficult to see how even a severe ding to the sump (which is thin material after all) will deform the threads *around* an already installed burly sump plug, might make them a tad tighter but you'd still be able to wind it out.
Get a single hex 29mm socket and undo it.
mrcheerful
I used a Stillson wrench on a rounded-off, over-tight sump plug with great success. Make sure you've got the replacement plug first. If the thread is deformed you may be better buying a pump as suggested by Sponix.
Try a inch and a quarter. It's more likely to be in A/F as it's an old GM lump.
The message from James Dore contains these words:
If all else fails, welding a tommybar onto the plug will probably do the job. More often it's the heat from that trick that does the job - but it does usualy work.
TBH, no - because I can't find a 29mm socket locally. I have tried molegrips, a large adjustable wrench, and larger adjustable wrench, which locked on to two faces, but wouldn't budge.
Will try the socket when I find one though.
Cheers,
Good Point! Well made! P'raps also explains the dearth of 29mm.
Ta!
More likely to be an "imperial" size rather than metric.
Usual rule there really, any American stuff and most British stuff before 1980 will be A/F.
That's where I fell over - the TR7 is all metric (from 1975) - never needed any A/F stuff with this or the other (mebbe the spark plug socket). All my previous motors have been french :->
Cheers,
A quick browse for 29mm sockets turns up that 29mm is a size commonly found on agricultural vehicles, especially Massey Ferguson.. ;-)
You reveal your youth! There were neither A/F nor metric nuts on my first wheels - a 1953 Matchless bike, and I've loads of Whitworth sockets and spanners here which were bought then and later. The value of Whitworth and A/F sockets these days is realised when metric nuts have been rounded-off by slipping spanners. There's usually a Whit. or A/F socket that's *just* below the (damaged) metric size, and can be hammered on the nut. Using those rarely fails to shift them. But why are (almost all) ring spanners and sockets bi-hex? It is they that damage the corners of recalcitrant nuts, whilst hex sockets take a much firmer grip. It is notable that the sockets supplied with my (compressed-air) impact wrench are all hex, not bi-hex.
Absolutely. I have a set of Whitworth sockets here too. I even have a small number of BA as well.
It is notable that the sockets supplied with
Probably because hex is the std for impact sockets.:-) Mike.
What does A/F stand for? I always understood it to mean across flats and could be metric or imperial.
-- Malc
Yes, it does mean across flats, but is always an imperial measurement when its used. It's yet another of the American terminologies that is wrong.
The Brits always used a spanner size that related to the thread size, as in Whitworth and BA.
The threads were usually UNC or UNF - Unified National Coarse and Fine) when related to A/F.
It was always assumed that a given thread size would yield a standard head size to match. Not only that, but spanners were also of a standard length so that a given force on the spanner would always apply the correct torque to whatever thread was being used - in skilled hands of course.
FWIW, metric stuff is also stated in thread size, its only the spanner size that isn't. All too often the metric stiff doesn't use a standard head either.
Most threads are 4, 6, 8 or 10mm, and have a much greater variety of pitch too. But spanner sizes vary from manufacturer to manufacturer. Europeans tend to use odd sizes, 7mm, 11mm, 13mm, 15mm. Japanese tend to use even sizes 8mm, 10mm 12mm, 14mm. However, above these things go somewhat astray. Although Ford use the normal odd sizes up to 15mm, above this they start to use 18mm, 20mm, 24mm. The Japs do the opposite,
17mm, 19mm, 21mm.
============== Many spanners were marked in both Whitworth and BSF sizes thus: 3/16 Whit /
1/4 BSF. An old engineer once told me that this was possibly due to the fact that the heads of Whitworth bolts were reduced in size relative to the threaded part as an economy measure during the war. I never queried this explanation but I still have the first set of spanners I ever bought - combination spanners (ring / open ended) clearly marked in both Whitworth and BSF.Cic.
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