MGB 5-Speed Gearbox

[dr_gn]

All, I’m re-commissioning my ‘62 MGB after a 20 year lay-up. It’s an original spec, matching numbers car, which was fully rebuilt in ‘89-‘90. It’s still in great condition.

It’s not the best car to drive, with the 3-synchro gearbox, and fairly lame stock engine. I’m fitting a Peter Burgess Econotune head, and Piper 270 cam (had the distributor rebuilt and re-calibrated to suit), and will have the engine balanced. That should improve performance and refinement (it’s the original 3 bearing engine).

I’ve got an original 3-synchro overdrive box in stock, which just needs re-furbing.

Question: Is there a 5-speed box which will fit in a very early ‘62 tunnel without any structural mods? The overdrive box was an option, so would fit straight in, but of course still no synchro in first, and the standard - rather gappy - ratios for the non-overdrive gears.

I want to make the car nicer to drive, and it’s the gearbox that’s my main complaint.

Any suggestions from those who’ve been there, done that? Cheers.

[grumpy52]

Best to contact any of the many MG clubs .
Gearbox conversions have been done loads of times and somebody will give you chapter and verse on the conversion .
I seem to remember that a Ford gearbox is the one of choice .
There is a good possibility that a conversion kit is available.

[dryden]

"The MG Experience" is a very good ( free ) Forum, massive content......everything you want to know.

[dr_gn]

Thanks all. I’ve been reading up on the various options, and one of the best seems to be the MX5 derived 5 speed, but at a price that I can’t really justify. I was hoping to get some real-world advice without joining yet another forum!

[Yertis]

My suggestion - join an MGB forum. Even if it’s just for this exercise. I’ve had a Toyota W58 5-speed gearbox fitted in the TR, but only did so after reading up on the experiences of others who’d previously done this. This type of modification seems far more common in the US - I presume the same would apply to MGs too.

[dr_gn]

Yertis said:

My suggestion - join an MGB forum. Even if it’s just for this exercise. I’ve had a Toyota W58 5-speed gearbox fitted in the TR, but only did so after reading up on the experiences of others who’d previously done this. This type of modification seems far more common in the US - I presume the same would apply to MGs too.

OK will do. I guess I might find a buyer for the early overdrive box too, if a 5 speed box turns out to be the best option for me.

[300bhp/ton]

On a slightly different note. The OD unit in my ‘78 B was IMO one of the best parts of the car. I loved the fact you only had four gears when not in a hurry. But could turn it into a 6 speed (or 7 if you got OD working on 2nd too) when you wanted something more spirited.

Personally feel it is a shame such boxes and driving experiences don’t exist today.

[Huntsman]

About 10 years back I did an MGA 1800 with 5 speed.

I used a later 18V block, with a smaller 3 syncro rear engine plate, flywheel and clutch, with a h-gear engineering bellhousing and a Ford type 9 box.

I'm fairly sure that would fit your car. Looks like Hi Gear are still going, a call to them would have you on the right path.

[dr_gn]

Huntsman said:

About 10 years back I did an MGA 1800 with 5 speed.

I used a later 18V block, with a smaller 3 syncro rear engine plate, flywheel and clutch, with a h-gear engineering bellhousing and a Ford type 9 box.

I'm fairly sure that would fit your car. Looks like Hi Gear are still going, a call to them would have you on the right path.

Definitely a serious option to consider - available to suit a 3-synchro tunnel with no modification:

https://hi-gearengineering.co.uk/mgb-5-speed-gearb...

Thank you.

[dr_gn]

300bhp/ton said:

On a slightly different note. The OD unit in my ‘78 B was IMO one of the best parts of the car. I loved the fact you only had four gears when not in a hurry. But could turn it into a 6 speed (or 7 if you got OD working on 2nd too) when you wanted something more spirited.

Personally feel it is a shame such boxes and driving experiences don’t exist today.

I totally agree that an O/D box would give a more old school feel to the driving experience, but on my early car I’d still have the noisy, harsh first gear. If I’m going to the trouble of a replacement box, I’d want it to be as refined as possible (within a sensible budget of course). If it was an all-synchro O/D box that I could fit, there would be no issue.

[Huntsman]

dr_gn said:

I’d want it to be as refined as possible

Isn't the logical conclusion of that a MX5 engine and box swap or a Zetec and type 9?

[dr_gn]

Huntsman said:

dr_gn said:

I’d want it to be as refined as possible

Isn't the logical conclusion of that a MX5 engine and box swap or a Zetec and type 9?

I meant I wanted the gearbox to be as refined as possible, if I’m going to the trouble of replacing it. If I was that concerned with ultimate refinement of the whole car, I might as well sell it!

[Huntsman]

dr_gn said:

I meant I wanted the gearbox to be as refined as possible, if I’m going to the trouble of replacing it. If I was that concerned with ultimate refinement of the whole car, I might as well sell it!

Good point!

Also, worth looking through the articles on MGAGuru on the flywheel, clutch, bellhousing variants. I *think* I remember that I had to re-drill my flywheel to make it all work.

[dryden]

Yertis said:

My suggestion - join an MGB forum. Even if it’s just for this exercise. I’ve had a Toyota W58 5-speed gearbox fitted in the TR, but only did so after reading up on the experiences of others who’d previously done this. This type of modification seems far more common in the US - I presume the same would apply to MGs too.

.
Very true for MGs, the overdrive gearboxes are rare in the States, as they were never spec'd from new, so they are highly sought after and expensive, hence all the Mazda/Toyota 5 speed swaps.
OP, Your 3 sync O/D box would be - very - sought after over there. Check out The MG Expeience foum,(MGB & GT) they have a buy/sell might be worth crating it for the shipping..

[fatfunkymonkey]

I’ve been keeping an eye on this company for when they do a conversion for my car http://www.frontlinedevelopments.com/part/new-mgb-...
Seems to be what you are looking for

[austin]

Huntsman said:

About 10 years back I did an MGA 1800 with 5 speed.

I used a later 18V block, with a smaller 3 syncro rear engine plate, flywheel and clutch, with a h-gear engineering bellhousing and a Ford type 9 box.

I'm fairly sure that would fit your car. Looks like Hi Gear are still going, a call to them would have you on the right path.

I'm doing this now with a Morris minor, Type 9 gearboxes are becoming sought after, it took me a couple of months to get a decent 5 speed one.

Plenty of people doing conversion kits, mines arriving today Once i finish removing the rusty bit & welding all the new panels in I'm hoping it should be a fairly straightforward process getting it in.

[Tyre Smoke]

What is involved with a MX5 box fitting?

Plenty of scrap/on their last legs MX5s with rust issues and solid engines and boxes.

[dr_gn]

fatfunkymonkey said:

I’ve been keeping an eye on this company for when they do a conversion for my car http://www.frontlinedevelopments.com/part/new-mgb-...
Seems to be what you are looking for

The price is way off for me.

[dr_gn]

Tyre Smoke said:

What is involved with a MX5 box fitting?

Plenty of scrap/on their last legs MX5s with rust issues and solid engines and boxes.

I’m guessing the Front Line Developments version has the necessary conversion parts.

[dr_gn]

Looks like the Vitesse and FRD boxes are the same?

It’s not the lack of synchro on first that bothers me, it’s that first gear is straight-cut (at least I think it is), its just so harsh, and the ratios are crap.