Having finished off the clutch re-visit, I've been enjoying the exploration of the OD. After the initial shack-down mentioned in the previous entry I was keen to give it a good decent run.
So after checking on eBay and finding nothing, I gave Heritage motors a ring to enquire about a OD speedo cable.
After some discussion on the phone it was established that they had one there and they would send it up to me.
"Hang on, I might take a ride down and get it." Ok, they will leave it on the counter waiting for me. If I change my mind give them a ring and we'll send it out.

Ok. Sounds like a plan. A good freeway run. Never taken the MGB that far into the city before.
So I set off. Top of the hill, just before the expressway, I stopped to fill up and I was a little worried 'cause it wasn't running real good - nothing magor - just didn't feel right. So I filled it with unleaded without ethanol. Normally I just run on E10.
Pulled over to check the tyres as well and popped the bonnet just to look at everything. Absentmindedly I reached in to check the plug leads.

Hang on! This plug's loose! WTF they're ALL loose.
Then it dawned on me. I'd taken the plugs out to turn the motor over for some reason that escapes me now and I remember just putting them back just to fill up the hole and thinking I'll tighten them later.
Well, I never did. What a bone-head! That could have been nasty.

Anyway I had a old plug spanner with me so I was able to pull them out, check them and tighten them back in. What a dingbat!

Any way after that it ran a lot better and I went down to Smithfield and back without a hitch.

Next day I put the cable it and all is well. The speedo is still not reading correctly but it is the same as it was before.

I'll have another go at sorting that out another day. It doesn't go all the way to zero. I believe that when I pulled it down a few years ago I didn't put enough tension on the spring inside.
I think it would be a simple matter to pull it down again and change that.

Started this morning and checked that the bolts would go in beside the U joints. Yes! Easy-ish!

So to drill the holes to couple it together.
I was anticipating this to be more difficult than it was so I've gone a bit overboard with the photos. So because I took them you have to look at them!

I thought that I was in for a long fiddly process of measuring and drilling the holes 'cause I wanted to sure they were accurate. Well hit on a short cut using an old valve stem that happened to be the exact size - 5/16". So holding it in a cordless power drill and resting against my bench grinder, I was able to accurately grind it to a point to act as a centre punch as shown in the series of pics below.

Close up of ground tip.

How it was set up to use.

The resulting punch mark. Probably more accurate than I could measure, mark out and then punch.

Then a 1/8" pilot hole. Allowed the the centre punch mark to do the precise alignment of the drill, holding it loosely so it can move to the exact place then holding it tightly. Only works with small drills.

Then using the drill bit to position, I clamped it in position for the next two drills - 19/64" and then 5/16" without moving the setup.

And the 5/16".


Using a short bolt to locate, the opposite one is marked and drilled the same way.

Using 2 bolts to positively locate, the other two positions are marked.

And the second one.


The two remaining punch marks are shown here.


After drilling I used a hand drill to slightly countersink the holes front and back.


And here's the finished piece from both sides.



Well I was ready to go! Well, no! In practice the holes were just a little snug so I ended up taking them out to 21/64" and they went together quite easily under the car.

The only other thing I had to do was deal with a missing screw retaining the speedo input. I couldn't find the screw. I don't remember taking it out so I'm thinking it wasn't there in the first place. I just wanted something to make sure the spindle wasn't going to fall out. So I found a bolt that fit 5/16" UNC apparently and ground a little spigot on the end and put it in with a bit of locktite. When I get my new speedo cable I'll sort it out properly.

Well that's it - so it's time for a test drive.

Again long story short - YES YES YES! Smooth clutch AND functioning OD.



Works great on the way up. Haven't mastered it on the way down. Remember I haven't got the vacuum switch. So in the meantime I'm clutching on the way down.

It's another good MGB day. Can't wait 'till I can give it a good test drive.

Did this on Friday - haven't had a chance to write it up 'till now.

Annoyed at myself for not taking more photos, especially of the block I started with.
Made more frustrating because the times I thought of taking pics I didn't have my camera with me, I'd completely forgotten about my new phone which has a decent camera in it and this was in my pocket the whole time! In fact the 3 pics I have I took with it. They're not great but certainly acceptable.

Well, continuing on, I needed a slug of steel about 86 x 30 and when I went to the steel merchants in the morning - I had to wait for them to open at 7.30am - the closest they thought they had was 90mm dia. Perfect! However, in reality they couldn't find that size in the yard so I went with 100mm dia x40mm. Just a 'bit' more turning. Cost me $15. Sort of a min charge, he reckons he actually gave me a 47% discount. Yeah right!

Still, not too bad.

Went to school to check that I was able to use the lathe and then went to the gym then home to do some 'housework'.
Went back in and spent a couple of hours and came up with this.
This is the side that the shaft attaches to:
I set this up in a 4 jaw independent chuck with the jaws reversed. The recess is a lot deeper than required but I did that so I'd have plenty to grip on the outside of the 3 jaw chuck jaws. (the reverse jaws of the 3 jaw had been lost many years ago.)


This is the side which goes to the box. I would have liked to have bored the centre right out but I didn't have time and I couldn't find a boring bar. Same with the large groove around the centre. It's a bit heavy.


This shot shows the spare flange on the adapter. The ring around the outside about 5mm up is simply a machining mark where i'd changed the angle of the tool. It's only visible and you can't feel it.


After this I took it to my bolts supplier to see about the studs before I drilled for those. Well, long story short, no studs available without special order or me modifying bolts. So I got 4 long bolts and I'll check if I can get them in the drive shaft flange before I simply drill the adapter 5/16".
I suppose that's the easiest and quickest anyway.

Stay tuned for that.

Mosquitos have been horrendous lately here at any time of day. So thick I had to give it away yesterday.

This morning I went mad with the Aeroguard and managed to replace the fuel filter and start it up again and run it for a few minutes. Smoked like crazy - oil on the exhaust I suppose. Anyway that seemed to disperse the mozzies and I was able to install the switch and the relay.

I used a existing screw to mount the relay and I managed to fit the switch between the fuel gauge and the vacuum gauge. PO had an ammeter where the OD switch blanking hole was and I replaced it with the vacuum gauge.

I felt that the switch should go somewhere there so that's where it went. See pics:


The relay just went where it is because that was where the screw was and it was close to where the wires came up from the gearbox. The two green wires that don't go anywhere are the reversing lights switch.


I made up some short connectors to go from bullet connectors to spade connectors because I didn't want to cut the harness wires. Did that so it can go to standard if I desire. This, however, makes it look a bit messy.

Finished off the inside and put the bonnet back on. That means it's all done except for the driveshaft spacer and I spent some time drawing it up and thinking about how I want to do that. Decided to go with double set of studs so I only have nilock nuts to worry about. Long bolts I don't think would go in.
Here's the drawing of that which I've yet to make.


Well that's about it. I ran it again and tested the OD solenoid and tried to hear whether it changed when the OD was activated in 3rd and 4th.
Solenoid clicked in and out loud and clear and I think that I could hear the output speed change but I can't be sure. I'll have to wait till it's on the road to be absolutely sure.

If I had the speedo cable I could tell from that.

This is the morning after. It was too late yesterday (well earlier this morning, actually) to be bothered writing this up but I did put an entry on the forum click here.

Started at about 9 am and immediately got side tracked with the side tappet covers.
I was pretty sure one of mine leaked so while the motor was out I thought I'd have a go at it. It was the front one and of course it leaked, the gasket was not thick enough to stick above the flange - even when new. I compared the old gasket with the piece that had come from the centre of the gasket when new and it had not compressed very much, if at all. It was always going to leak.


You can see here that it doesn't fill the recess.


So I covered everything and went off to try to by some thicker cork stock. Long story, short, no joy there so I used some thinner stuff I had and added it to the original gasket with lots of gasket goop. The back one is a different design and it was sealing well. I had to take it off to establish that but it went back on with a fresh coating of goop as well. If they leak now ...........!

Ok didn't actually get to the motor/g.box install 'till about 1 pm or something like that. Cleared the garage and lined up the car with the chain block.


Moved the unit into position and hooked up the cable to it and the chain block while still on the stand.


Lifted it up a little, unhooked the stand, lifted it clear of the guards, spun it around and pulled the car under it while letting it down gently. The chain block is very precise and it take no effort to raise or lower it just a little. I had almost everything left on the motor so it was a bit of a tight squeeze but with the trolley jack underneath to alter the angle as I went down and in, it finally was resting on the front engine mounts.


A little jiggling while gently lifting and lowering and I was able to get the bolts for the mounts in.


Next the infamous crossmember. It was then I realised that these weren't where I wanted them to be.


Not such a big deal but I wanted to minimise the time I had to spend under the car.

Well, I managed to get them on without much drama. I actually found it easier to do it completely by feel with my eyes shut.
The crossmember was next and I installed the stay rod to it on the bench to try to make it easier and I'd already done the modification to the crossmember so by moving the supporting trolley jack away from the stay loop I installed the crossmember to the gearbox and then, using the jack to raise the whole lot proceeded to install the crossmember bolts. Wow, this was not going well until I realised that the OD gearbox uses different screw holes and these had not been used ever. After struggling with the bolts and actually getting all four in but unable to tighten, the penny dropped and one by one I took them out and ran a tap up the holes.
What a difference! No photos of the cross member unfortunately.

Anyway, I had to stop there as Sharon and David came home and were expecting dinner.

After dinner I went back out to clean up but ended up continuing and got everything else hooked up and gave it a test run.

Well one little hiccup. I must have damaged the metal fan on the front of the generator and it screamed like a banshee till I bent it back into shape. Took me a while to work out what the god awful noise was and there was a 'small' amount of panic when I started it up.

And I've got a fuel leak at the filter. Haven't looked at it in detail but I may have split the filter, plastic, generic just before the carbs.

However, all is well (ish).

The tailshaft is not connected yet but I engaged all the gears and the box is nice and quite. Not definitive yet but a good sign. Took me about an hour and a half to clean up and pack everything away.

It was just on 1 am when I'd finished and by the time I'd cleaned up and had a shower I didn't get to bed until about 2 am.

This morning I took these 2 pics:


Still some work to do on the inside:


It's 1.30 pm the next day and I've been to the Gym and I picked up a new fuel filter, a bit of fuel line, a generic switch and a simple relay. I'll fiddle about with those bits this afternoon - maybe!

Last 2 day have been 'fiddle about' days.
The wiring up and a few decisions to make about what to do about some issues have taken much longer than I had anticipated.

The new harness came with the reverse and OD harness and I'd packed it away a few years ago. Got it out and wired it up. The 3rd, 4th lockout switch had been replaced with a screw terminal version and rather than cut off the clips on the harness I modified some spade terminals and screwed them in and clipped the harness to them.


Attached the harness to the side of the gearbox with a combination of cable ties and a 'P' clip. I drilled and tapped an unused spigot in the side of the gearbox. A bit DPO but the result is neat. Also drilled a couple of 3mm holes into casting webs to use cable ties. (Very DPO)




Then it was time to address the adjustment of the OD solenoid. The manual was a bit sketchy in this area but it became clearer when I actually put power to the solenoid. It pulled in a lot further than I thought it would and it was clearer what the manual was describing.

I've covered the control arm up but it is clearly depicted in the manual. A 3/16" hole is in the brass control lever and it matches a hole in the casting behind it. At rest these two should line up. Well the at rest position is debatable and as the plunger can flop around all over the place when no power is flowing I determined close enough was good enough and went about adjusting the arm at the fully engaged position. Logic and the manual and the Moss video mentioned in a previous entry made it clear that the solenoid drew a lot of current when it was being activated but at the end of it's stroke it only needed a small current - less than 2amps to hold it there. A switching mechanism was built into the solenoid at the end of its pull stroke to drop the current from about 15 to 20 amps down to 2amps.
I just had to make sure that the plunger got to this position at the same time as moving the lever to almost it's full movement.
I needed to be able to measure up to 20 amps. Hmm, both my multimeters only go to about 500 Milli amps. I was almost at the point of giving up when I remembered the PO had an ammeter in the dash when I bought the car and started to search for where I'd put that when another light bulb moment and I remembered my old engine analyser that had been given to me maaany years ago but my college mates on my 21st. I sure it had a method of measuring alternator output so it must go into that kind of range. Well I dug it out and found that it did by using a shunt.
Used my jump start battery (almost flat) and hooked it up and got the 2 readings that I required - albeit a bit low because the jump starter was almost flat but there was enough to show a reading of about 10amps and then dropping to about 2amps.
High amp reading: (should be about 20 amps it's not because the battery was almost flat)

Low amp reading: (Really just a deflection of the needle)


I fiddled about to make sure I was stiil getting full movement on the arm when engaged and it was still a bit slack when disengaged. And I was done.

Used some locktite on the cover plug I got the other day and attached the cover,




All done ready to go!

There was some discussion about the use of the vacuum switch and relay on the forum. I've decided not to use these at this time. I'll just put the link to the discussion by way of explanation.

Link to forum discussion here!

Maybe the lump will go back in tomorrow.