Anything and everything Spitfire.

Clutch, gearbox, overdrive, propeller shaft.

Right, suddenly the other day i was finding it really difficult to get the car into 3rd gear, and even more difficult to get it out again, but the other gears didn't seem to be much of a problem. Looking at previous posts the likely culprit is the 3rd gear circlip, whatever that is.

So with this in mind how easy/difficult is it to change this, as i have never had any experience with gearboxes before. Are there anything tricks or tips to getting the thing out of the car, and should i be replacing or looking at anything else if i'm taking it out?

Its a 1500 so i'm presuming it'll be a single rail gearbox.

Thanks for any help.

Charlie

It is more than likley that this will require a complete dismantling of the gearbox. This of course will give you the opporuntiy to refresh the whole thing if you are planning to do it yourself. However, the simpler option is to buy an exhcange gearbox and just change it over.

...they cost in the order of &163;225 I think these days (plus surcharge - but you should get that back). You may also get a two year guarantee with the new box. I know where I'd go for on without a second thought but I recommend shopping around for whats best for you.

Ok i've taken my gearbox out of the car, and it doesn't look the same as the ones in the haynes manual.

Pictured here:
http://www.tssc.org.uk/profile.asp?profile=70012&v...

Number on the side of the box: 13H6 RKC 0461 i think it was very grubby, and the number on the top plate: BSK TKC1256 V3331

Now as my car's engine was replaced by the previous owner to a dolomite 1500 is it likely they took the gearbox over as well? If so how do i get into it to remove the mainshaft?

Charlie

That's a single rail.

Even if it was out of a Dolomite, it would still be a single rail - identical unit except for the mount at the back. That can be drilled and tapped to end up just like the Spitfire version too.

Yup, looks like a single rail box with a J-type overdrive.

Yup - one of these http://www.canleyclassics.com/infodatabase.asp?art... in fact that is THE box I had done to fit to my old Herald - if you look carefully you can see "Jason" written on it! Fame at last

The box came out of a 1500 Spit - a little parts swapping and it went in easily, changed teh clutch plate and shortened the prop.

Just had a quick read of that article, and interested in the "Oil leaks - before attempting to trace a leak make sure that the gearbox/overdrive unit has a breather somewhere that is clear." section.

I've got a single rail + J-type which leaks oil in my car - anyone tell me where the breakther is/should be, and what to look for?

In general terms, your gearbox is about the same beneath the selector casing as a 3 rail 4 synchro Spitfire gearbox. The basic design is the same, but the ratios are different and any parts should be bought as Spitfire 1500 (or Dolomite 1500 etc).
Hence, once the top cover is off, dismantling etc is the same as for earlier Spitfire. (However, although again similar and a direct descendant, this is NOT the same as a Herald or Spit 1-3 gearbox. Big difference is synchronised first gear).
If it's at all like the earlier gearbox, I think the problem being described to you is breakage of the circlip that holds the complete gearcluster to the mainshaft.This is at the FRONT end of the mainshaft and does not require removal of any of the mainshaft components. That's the good news!
BUT, to get at it properly, you need to remove the overdrive (so you can tilt the mainshaft up and remove it from the gearbox). Also, remove the layshaft and drop laygear into the bottom of the box. While it can remain there, unfortunately it's highly likely that all the needle rollers will fall out when you remove the layshaft so you would not be able to reassemble unless you can arrange a short dummy shaft to retain them in position.
Also remove the input shaft (forwards). Then you can see the front of the mainshaft and hopefully the suspect circlip. To deal with it properly you need to drive the mainshaft forwards out of the gearbox housing and deal with on the bench.
This then begs the question of, having come this far, what else do you replace. Changing the main bearings (and DEFINITELY the roller bearing inside the input shaft, in which the tip of the mainshaft locates) requires little further dismantling, but that still leaves layshaft roller bearings, layshaft thrust washers, and the synchro rings, all of which wear).
If you are really unlucky, the mainshaft tip can snap off and cause such 3rd gear problems, although that is much more of a problem on earlier gearboxes and D type overdrives, especially if the shaft has been "retipped". This might also result in more overall noise in ALL the indirect gears but normal (relative!) silence in 4th.
It IS also possible that sudden difficulty in engaging 3rd gear could be breakage of the springs within the 3rd/4th gear synchro hub, but that would probably also affect 4th gear to an extent and does not really explain difficulty in DISengaging 3rd.
All this IS DIYable and most manuals are quite good about the processes, but can be quite involved which is why a lot of people opt for an exchange gearbox.
While it is out of the car it might at least be worth taking the top off and seeing if there is anything obviously wrong with the 3rd/4th gear synchro hub which might account for binding etc.
If, with 3rd gear engaged (synchro hub moved backwards) there is signs of the mainshaft being able to be moved sideways (or upwards) in relation to the input shaft, that might hint at a broken mainshaft tip. However you would be surprised that the input and main shafts do have SOME movement anyway.
If, with 3rd gear engaged, it seems that you can move the 3rd gear itself forwards by more than a few thou, then the circlip may be broken. (However, the gear will be held by its engagement with the layhsaft gear so things may not be too obvious!)

Well it was the third gear circlip that had broken in the end, it was in three pieces! Unfortunately i didn't use a correct size dummy layshaft and the needles fell out, so i've taken apart the gearbox completely now, and i've bought various circlips and a reverse idler gear that was looking pretty worn, and i'm going to attempt to put everything back in the right place and get it back in the car.

Looking at the moss catalogue it has three tension springs between the thrust washer and the bellhousing in the exploded diagram, as i don't think these were in the gear box when i took it out, but there does appear to be three holes for them so should i put some new ones in?

Charlie

Oh dear, I bet you had a rather sinking feeling when you found the layshaft would not go back in properly, and another one when you realised what you were going to have to do to put it right!
Now the gearbox is in bits, you should seriously consider doing a more major overhaul. The bits are not too expensive, but the labour of taking it all apart and reassembling is, so now is an obvious time to do this unless you know the rest of the box is fine and the circlip was the only problem. (Any indications why it broke?)
I would definitely replace the needle roller bearing inside the input shaft. I would almost certainly replace the two main ball races for the input shaft and mainshaft. I would also replace all the layshaft rollers.
Measure the layshaft end float. If it is over spec, see if you can get new thrust washers. FITTING THE SPRINGS will not change the endfloat, they just stop any chatter at idle by holding the thrust washer against the laygears. It is quite feasible to run without them. Although Vitesse's had them, related Herald boxes did not, so they do not seem to be essential. If they are readily available and cheap, I'd probably fit them, but I'm not really sure why I say that!!!!!
The big "do I don't I" question nowadays is whether to change the synchro rings. If you have a decent manual, you can get an idea of how worn they are (you also need to see whether the internal ribbing is worn down). While they are easy enough to change while the box is in bits, I'm told that the quality of riungs available these days is not good or at least patchy, and so you might be wasting your money.

Section : Gearbox

3rd gear problems

Followups :

3rd gear problems

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Where is this gearbox from?

Where is this gearbox from?

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Where is this gearbox from?

Where is this gearbox from?

Where is this gearbox from?