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MG Midget and Sprite Technical - gearbox

Hi all,

long time without posting (had escaped the underside of the midget for a while but am firmly back under the bonnet!),

finally decided to get on with my 5 speed conversion and am in the process of hunting down an in expensive gearbox. Found this one but appears to have a hole in the casing behind the gear stick.

Is this an issue? I cant see if it would allow oil to leak (I'm assuming not) and if I just plug the gap to stop dirt getting into it I'm guessing it would be fine.

Thoughts?


James Ballard

There should not be much (any) oil at this point as the oil is held far forward, in the remote, by a seal. I would build up the area to seal against dirt ingress. Go for it!
Alan (Greenhithe) on John Clark's computer.
J R Clark

Hmmm. Not so sure. It's a type 9 right? There's a lip seal at the back which runs on the propshaft yoke. I had that seal fail in a kit car and it lost loads of gearbox oil out of the back where the seal should have been - so there's definitely oil that far back!

I painted mine in hamerite blue too ... too much of a coincidence for it to be the same one :o)
Ant Allen

The damage is above the rear oil seal. The breakage is around the metal end piece where it fits into the alloy casing. The metal plate is a dust / dirt seal preventing ingress into the remote linkage. The remote linkage requires greasing as lubrication because oil does not reach this far due to an oil seal further into the remote casing. It seems silly to me to write off a good gearbox when that area can be built up with a filler if the expense of tig welding is beyond the pocket.
Alan.
J R Clark

Ah ok - so there's oil in the lower section where the yoke fits, but not in the upper part. That makes sense. Sorry for the confusion.

Ant
Ant Allen

Thanks for the advice chaps!

Here's to a 5 speed '09!

J
James Ballard

You can of course just replace the tail casing.
Daniel Thirteen-Twelve

If swopping tail casings ensure that the speedo drives are the same and engage 4th gear so that the brass bit with a slot in it engages with the long pin in the remote. Not very technical but you will know what I mean when you see it apart.
Alan (now on my own computer not John Clark's)
Alan Anstead

That's a similar arrangement to the box in the 1500 Midget. Not long back I replaced the gaiter around the gear lever, and while I had gaiter and draught excluder off, I noticed that the round cover piece in the rear of my remote housing was missing. Of course none of the usual suspects stock that bit, and when I contacted a local mg specialist, he said not to worry about it. So I greased up the linkage in the remote and reassembled everything. So if it's any comfort, the hole in my remote is bigger than the one in yours!

Cheers,

-:G:-
Gryf Ketcherside

On the other hand.... ensure the tail casing is different if the damaged one is for the electronic speedo!

Alan makes a good point about the pin. The long pin will work with both types of selector springs but the short one only works with the spring it's intended to work with.

Note that NOT all selector springs are of the brass mechanism piece design so you might not have a brass piece at all. There is a photo of this in a well known Sprite/Midget tuning book specifically to illustrate the difference.

Or do you mean a different bit altogether Alan?
Daniel Thirteen-Twelve

Enjoyed your book as I did the previous editions.
We are on different pins.
Inside the remote casing and pointing forward is a long, "knitting needle", type pin. It has to locate in the inverted U on a brass component on the remote end of the selector shaft. To ensure that the two parts marry on assembly 4th gear has to be engaged.
Alan.
Alan Anstead

On one occasion I re-assembled my gearbox and didn't select 4th gear at the right moment. The "knitting needle" pin missed its target. As everything seemed to go together OK I only discovered when it was back on the road that 5th gear wouldn't engage properly.

The reference in Haynes (Sierra manual) is brief and VERY easy to miss as there is no comment on why you should select 4th or on what happens if you don't.

James, that hole in the casing is of no consequence at all. Unless you already plan on disassembling the gearbox I wouldn't bother/ risk disturbing things by removing the rear casing. To keep crud out repair it with some epoxy or even just wrap it around with some duck tape.

Guy
Guy Weller

Guy
How do you think I found out?
Alan.
Alan Anstead

And there was me thinking no-one else would be so foolish!

I also, on a different occasion, managed to put the 5th gear slotted collar thing on the wrong way around. Its dimensions are such that it actually looks as if it is designed to go on the wrong way! That error also only manifest itself after everything was back together in the car. That resulted in an engine out and back in again, repeated twice in the same weekend. Glutton!

Guy
Guy Weller

Hi Alan,

On page 87 of the 2008 edition there is a photo of the selector locking control mechanisms. The brass one on the right is the one you have. The grey metal one on the left is the one you don't have in your particular box. The measurements of the knitting needles is in the text.
Daniel Thirteen-Twelve

Daniel
I referred a chap, on another thread, to obtain a copy of a club magazine with articles in about fitting 5 speed boxes and nearly started WW3. How do you get away with it?
Referring to S*d's Law I found out about this problem before your book was published but fortunately, unlike Guy, also before fitting the gearbox into the car.
Alan
Alan Anstead

I guess I have upset a few people in recent months - though some ignore me rather than attack me! I also guess I provide more information more often than I plug my book and bit my lip often.

I'm also not a member of any club and at peace with everyone in the recent war!
Daniel Thirteen-Twelve

When on this BBS I sit in front of the computer now wearing an old ARP helmet in case of falling stones.
Alan.
Alan Anstead

Daniel

I must confess I have now conceded defeat and ordered the 2008 edition of your book as my 1992 edition does not have the info I need and the next job to tackle is engine and gearbox replacement.

Anybody got a 'Tuned' A series and/or Type 9 gearbox and bell housing that they no longer need?

Shaun
Shaun

Are you after a type 9 bell housing or an A series bell housing? If and when I get the new box in the type 9 bell housing will be excess to requirements. As will a pretty decent 1500 4 speed if anyone is interested...
James Ballard

At the moment I am up either for a 'A' or 'K' bell housing just depends what comes up first and at what price.

Shaun
Shaun

Hi James,

Still need that type 9 box? I have a spare taking up space in the UK!

Drop me a line if you're interested!

Cheers,

Eddy
E.J. Veuger

This thread was discussed between 06/01/2009 and 12/01/2009

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