Gearbox bolts... Any thoughts?!

shouldhaveboughtahouse

shouldhaveboughtahouse

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Hi all, so I'm at the stage of disconnecting my md7a gearbox. Does anyone have any idea what these mounting bolts are or how to remove them? They've obviously been in place for years but I can't make out if they are bolts or need something like an Allen key or something as-yet unidentified to get them off.
Any help much appreciated, I'm 4 bolts away from liberating the gearbox!
Many thanks in advance
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shouldhaveboughtahouse said:
Hi all, so I'm at the stage of disconnecting my md7a gearbox. Does anyone have any idea what these mounting bolts are or how to remove them? They've obviously been in place for years but I can't make out if they are bolts or need something like an Allen key or something as-yet unidentified to get them off.
Any help much appreciated, I'm 4 bolts away from liberating the gearbox!
Many thanks in advance
Click to expand...
They are described as "Hex socket screws" in the parts list

1774809321265.png
 
That is a cap screw or as per manual a hex socket screw.
And if that is the BEST one you will need to get serious.

I would not try to undo it without some serous heat.
Then cold water.
Then heat .
Then anti rust treatment.
Then heat.
Then wire brush.
Then more heat.

Then when you find that they won't budge, cut the heads off and drill out and tap out the holes. Or get a machine shop to do that for you.
The alternative is don't bugger around trying to remove them and go straight to cutting off.

gary
 
Once cleaned and soaked could try a hex key, plus it would seem room, for a pair of grips round the head as well.

I have recently had great success with plus gas on a stainless bolt in aluminium, though luckily the corrosion wasn't to bad.
 
Boater Sam said:
Diagram says hex socket screws so an Allen key but you need to do some serious de-rusting and get lots of penetrating oil on for several days before trying to undo them.
Click to expand...

The finest penetrating oil cannot do a lot until it has somewhere to penetrate, so clean it up as well as you can first. Also it will do its job better if you can get any movement from the fastener at all, sometimes it can help to try a slight tightening first to crack the "seal". Once moving keep tightening and loosening, rather than try to just wind it out in one go.
Can you see any thread protruding at the other end or is it a blind hole? If so, that is somewhere else to give the treatment to.

In my experience, the list of helpful penetrants starts with a 50:50 mix of REAL Acetone and ATF. Apply with an artist's paintbrush a few times over 24 hours and more once the fastener starts to move. Shake the jar to mix it before use.
Second would be neat diesel, followed by commercial preparations like PlusGas.
(Original) Water Dispersant 40 is one up from water but I have never tested the actual penetrant that WD also offer now.

If feasible, heat is often very useful. A borrowed induction heater would be ideal, a naked flame possibly a bit risky if in situ.
 
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Well maybe be wrong but that in the first bigger picture looks like just a boss in the casting. Pretty hard to tell without cleaning it up more.
 
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