Herald 1200 3 syncro gearbox

[Neilriser]

Hi to all,just finishing all bodywork on my refurb and body due to go to painters soon.Starting to think about gearbox,ive been quoted large amounts to have bearings/seals etc,i can do this myself i dont want to change everything just for the sake of it,what would be the general advice be to get started please,the engine/gearbox last ran about fours years ago when original owners drove it onto the trailer,although coughing and spluttering they are both an unknown quantity.Regards Neil

[glang]

With gearboxes you dont have to change anything for the sake of it. Of course as its not a massive job to remove and if it spins plus all gears select ok you could just install it and drive the car to identify any problems with it....

Otherwise you need to dismantle it pretty much completely AFTER taking some measurements of various clearances and then inspect the components. Undoubtedly you'll find some wear on the surfaces where bearings run so then you need to decide if its too much and if you can find replacement bits... Likewise with the gears, synchros, other bearings and clearances measured earlier so you can decide exactly what you need taking into account availability and the limited mileage the car is likely to do in the future. Your not going to get the gearbox as new but by replacing selective bits you can have one for a reasonable cost which will last for years👍 

The free to download workshop manual has all the info including the various tolerances.

[yorkshire_spam]

Not sure about that specific gearbox, but with the Spitfire late single rail gearbox the appropriate input/mainshaft bearings are incredibly hard to find in a decent brand/quality and very expensive if you do. I'd take a very careful look at the existing ones before considering expensive and potentially inferior replacements. (assuming there's a similar situation with your Herald box)

 

[Clive]

No reason to change bearings if they are still good. The trouble is knowing how a good bearing feels. Likewise the layshaft pin, and synchros. 

A friend is very good with gearboxes, but he is always very keen to know what issues a  box has before he strips it, so he has a clue what he is looking for. Indeed when I took my T9 box to BGH they wanted to know why I wanted it worked on. 

So if you have no experience with gearboxes, it may be best to simply clean it out, waggle the input shaft to feel for excessive play (usually the mainshaft tip bearings) and change the rear seal. I think the frnt has a scroll seal, so not replaceable, but you should check. Then drive the car once assembled, and hopefully all is well. 

A lot of the money is the labour to strip/clean/inspect/reassemble a gearbox. So that is unavoidable if you get somebody to do it for you.

[thescrapman]

And if it is a duffer, 3-synchro non-OD gearboxes are plentiful and cheap.

[glang]

How do you pick a good one though? By now if a used box isnt running well in a car chances are its knackered something, which as said, you cant tell from the outside☹️

[glang]

You were lucky Wendy as I cant believe that included any new gears or fancy machining?

[Neilriser]

Many thanks for replies ive been quoted 495 +vat for bearing replacement or 995 +vat for a full recondition,what exactly would one expect to be done for a full recondition? neil

[glang]

For the full recondition I would expect the surfaces where needle roller bearings run to be as new (including their surface hardening). The main shaft appears to be available but the input gear is not so I would like to know how this would be reconditioned correctly.

Also all clearances in the gearbox should be within Triumphs specification which may require new thrust bearings and sleeves some of which are no longer available...

Really you need a company who will dismantle the unit and then talk to you about what theyve found, what they recommend and how far (including expenditure) you want to go.

[Wendy Dawes]

Ken is excellent but has a special rate  for regular customers and recommendations,  he is well known in the classic world in the West Midlands  he has a proper old fashioned workshop with boxes of parts tucked away  

Edited November 26, 2023 by Wendy Dawes

[glang]

That sounds exactly like what you want! Ive got four used gearboxes in bits at the moment and selecting the best from each (where compatible) to hopefully end up with a healthy unit although Im still going to have to get creative to repair the mainshaft tip. The end result wont be new (no new components except some synchro rings) but, with the mileage I do, should last me out😁

[thescrapman]

19 hours ago, Neilriser said:

Many thanks for replies ive been quoted 495 +vat for bearing replacement or 995 +vat for a full recondition,what exactly would one expect to be done for a full recondition? neil

£995, plus vat, Jesus! Is it gold-plated???? With an enormous diamond for a gear knob?

I purchased a J-type OD box built with NOS gear set a few years ago for less than that price.

Even Fitchetts are charging less than half that for a recon exchange box.

I reckon you could buy about 40 secondhand boxes for you £1200, bound to be enough bits to make a good one.

 

[glang]

I would imagine hes kept pretty busy and has quite a waiting list?

[Neilriser]

If i go the way of a Fitchetts recon gearbox what exactly would have been done to the box? just interested to know what it involves.

[glang]

Best to speak to them directly I think but generally all main components of your box have to be serviceable so just the rebuild kit as sold by the main suppliers is used....

[Clive]

5 hours ago, Neilriser said:

If i go the way of a Fitchetts recon gearbox what exactly would have been done to the box? just interested to know what it involves.

Most of the people building gearboxes or diffs rely on a supply of "core" stock from dismantled units. So when inspected, they will replace any damaged or unservicable parts with good ones. This may apply to bearings too. 

My t( box needed a 5th gear, BGH supplied a good used one. Likewise they replaced some of the synchros with better used items, as they refuse to use any of the new synchro rings available. A lot of this stuff is down to experience of the builder. 

And teh kicker is that with diffs, some shims are impossible to find. As the stock of used ones disappears (as it now is) goodness knows what will happen. Recently one of the guys who has been doing these for many many years said he had trouble finding shims for a rebuild, having to take several apart to find one that was usable. He has a lot of core, but no longer offers diff rebuilds. Expect to see this to spread.