Which holes on the gearbox cover for the long screws?

[Chief]

Hi,
Found a handy photo elsewhere on the forums:


Please could someone tell me which of the four holes are for the longer brass bolts as I'm fairly sure when I removed mine the long bolts were in various locations (along with a couple of M10 self tappers ).

Thanks,
Chief

[kevin s]

I believe they are the 4 that go through and screw into the gearbox crossmember.

[taupe]

Its a while since I looked but surely those are the four screws that screw into and secure the gearbox crossmember from the top?

T

[philthehill]

The four long brass screws (Philips No: 3 head) fit into the four captive nuts of the gearbox cross member. The rest (also with Philips No: 3 heads) are filled by the shorter brass screws.

[Chief]

I've read that too about them going through the crossmember, but I left that bit off from my initial post as I don't know which ones those are on the upper side of the panel now I've spent several hours getting all the holes to align by having to put in some screws.

Also there's a forum thread on here that warns you they're PZ3, not PH2, and you can ruin the heads using a PH on them. I can atest to this which is why ESM will be sending me some new ones thanks to using PH before I switched to a PZ screwdriver bit

[simmitc]

From underneath the car, push a thin piece of wire up through the gearbox cross-member captive nut. Where it pokes through the cover inside the car, put a dab of white paint next to the hole and you'll always know in future. You need to push the wire through only one hole as you'll be able to work out the other three from the first one

[Chief]

Have to admit I was trying to avoid doing that as I already have spent several painful days under the car (squirming doing the work I was carrying out as there's no room for the jack/axle stands currently) and I was giving my neck and shoulders a rest.

Oh well, was worth a try

Thanks for the replies

[philthehill]

Just checked again and the screws are PH3 not PH2 as I originally thought (have amended my post above). Never had any problem with using a PH screwdriver. Just tried a PH3 screw driver in a new brass screw and it is a perfect fit.
I have now found a PZ3 screwdriver bit and tried it in the head of the brass screw and there is very little difference in fit between the PH3 and the PZ3. So in conclusion either will do. It will help if the screw threads in the captive nuts are run through with a tap and copper ease grease smeared on the screw threads.

[philthehill]

I have found some brass gearbox cover screws and they are not marked as Pozi drive and they are PH3.
I have also found some later brass gearbox cover screws and they have the Pozi drive marking on the head and they are PZ3.
So in conclusion the brass gearbox cover screws could have either PH3 or PZ3 heads. Just look for the markings on the head (see link below).
I would suggest that the Philips PH3 brass screws (invented in the 1930's) were used by BMC before the introduction of the Pozi drive PZ3 brass screws (Posi drive screws were patented in 1963).
I would also suggest that later after market screws used PZ3 heads.
BMC parts manual lists the screws as Pt Nos - AJD2446B & AJD2448B (long). There is no reference to the type of head in the parts list.
https://www.albanycountyfasteners.com/b ... -phillips/

[simmitc]

And to complicate matters even further, the last few that I purchased from a well known Minor parts specialist arrived with slotted heads Still, no confusing which type of driver to use

[Chief]

I have found some brass gearbox cover screws...

Good ol' albany country fasteners, not the first time I've used their site for things like this. Also, mine are all Pozi, except for the ones that are Mangled

Minor parts specialist arrived with slotted heads

Hmmm, I'll have to order a few soon - I'd not be so happy having some a different head, it was painful enough finding a PZ3 amongst all my PH bits

[philthehill]

I was referring to brass gearbox tunnel screws I had in my stock box - not from Albany County Fastenings.
Here are the right screws from ESM.
https://www.morrisminorspares.com/searc ... fscr830862

[simmitc]

I think that's the short one, they also list the long one separately.

[Chief]

I was referring to brass gearbox tunnel screws I had in my stock box - not from Albany County Fastenings.

I meant I'd used them for information thanks to their excellent information pages

[Chief]

As a final update to this thread:

When looking at the cowl, of the four screws that surround the master brake cylinder access hole, the two to the left (closest to the gearbox tunnel) and their twins on the oppoisite side of the tunnel are where the long screws go.