Project Korean Cortina - going back in time!

[mat_the_cat]

Bugger. Just been informed that the layshaft and pinion are no good (not too surprising given the lack of oil) but the real downer is they haven't been able to obtain spares, as it is the rare 2wd 'box.

Shitefest looks unlikely to say the least, in this car

[Matty]

How possible is it to adapt to use a more common rwd box? Even type 9s seem expensive now and apparently aren't the strongest. Surely loads of people have used a variety of boxes with rv8s?

[mat_the_cat]

Lots of things are possible, the T5 gearbox is lighter and arguably a better 'box. But desirable and pricy! The Supra gearbox another option  but both require another bellhousing, fabrication of a mount, and what are the chances of the shifter coming up in the right location? I lucked out on that one the first time round!

[somewhatfoolish]

MT75 would do, but finding a non-transit one with reasonable ratios is probably a challenge these days.

[Stinkwheel]

Probably also rare but werent renault 25 gearboxes known for their hardiness? Worth a consideration ? ( i know nothing of dimensions, just that they used to handle good power)

[artdjones]

Rimmer brothers are listing recon boxes , but £1100

[mat_the_cat]

33 minutes ago, artdjones said:

Rimmer brothers are listing recon boxes , but £1100

Unless I'm missing something, that's the LT77, and out of stock? It would physically fit, but think the mounts are in a slightly different position. And more importantly, the shift pattern wouldn't match the original Hyundai knob!

[Matty]

2 hours ago, mat_the_cat said:

And more importantly, the shift pattern wouldn't match the original Hyundai knob!

Good anti theft device? 😆

[Zelandeth]

4 hours ago, Stinkwheel said:

Probably also rare but werent renault 25 gearboxes known for their hardiness? Worth a consideration ? ( i know nothing of dimensions, just that they used to handle good power)

FWD though so not much good here.  Plus I don't imagine they're exactly easy to find these days either.

[Stinkwheel]

Just now, Zelandeth said:

FWD though so not much good here.  Plus I don't imagine they're exactly easy to find these days either.

often used in RWD applications though. Audi V8's into Citroen H vans being the one im familiar with, but totally (probably) not easy to find, agreed

[Conan]

Renault 25 gearbox wouldn't be of much use as the output shaft send power to the sides!

[mat_the_cat]

Think it's often used as a transaxle, which would help weight distribution, but rather more work than I want at the moment!

[EyesWeldedShut]

41 minutes ago, mat_the_cat said:

Think it's often used as a transaxle, which would help weight distribution, but rather more work than I want at the moment!

Be entertaining for us tho'?
No chance you could source a secondhand layshaft/pinion gubbins for Ashcroft?

[mat_the_cat]

Attached to a gearbox, yes...

In which case timewise I'd be better off sticking in the used gearbox, and searching for the bits to rebuild .one long term.

[Rocket88]

Any good?

[warch]

There are several rwd R380 gearboxes on ebay at the mo, but I suspect you already know about them. 

[mat_the_cat]

4 hours ago, Rocket88 said:

Any good?

It would be an option, but I'd prefer to stick with the R380.

3 hours ago, warch said:

There are several rwd R380 gearboxes on ebay at the mo, but I suspect you already know about them. 

I know of one, which is potentially collectable on the way back from holiday. I also have a friend with one, but he's never driven it. So a couple of current options!

[Andyrew]

On 7/3/2023 at 11:50 PM, mat_the_cat said:

Bugger. Just been informed that the layshaft and pinion are no good (not too surprising given the lack of oil) but the real downer is they haven't been able to obtain spares, as it is the rare 2wd 'box.

Shitefest looks unlikely to say the least, in this car

Not sure where your at stage wise with the busted gearbox but im local to ashcrofts ( used to work there! And mate still does) so if you want the parts collecting and bring to the FOD i can arrange that if its saves postage/collection. 

[mat_the_cat]

Thanks, that's kind of you to offer, although I actually collected the remains this morning on our way back from France. It was only a 2 mile detour, so would have worked out perfectly had they been able to rebuild in time.

I've not had a good look at things yet, but I can't see any signs of major wear. There does appear to be a bit of heat discolouration though, which if it's softened the heat treatment would result in rapid wear...

The only pleasant surprise was not being charged for the stripdown work, which IMO they would be justified to. If I can find the parts in due course I will attempt a leisurely rebuild myself.

In the meantime I've agreed to buy a 'box from a friend, at a price between mate's rates and market value. It's less than I expected to pay, and more than he paid for it years ago, so we're both happy

[beko1987]

Week to sf... Reckon you'd do it? 

[mat_the_cat]

That would have been easily possible, except I won't have the gearbox until next weekend!

[mat_the_cat]

I've had a look through the bits, and have possibly spotted the failed bearing...

That's fairly conclusive then! Also I was right about glympsing the heat damage to the layshaft and input pinion. It doesn't photograph very well, but although negligible wear you can see the purple tinge indicating it's been softened.

Hopefully in a week's time I'll have the replacement, and be able to make a start fitting it.

[somewhatfoolish]

2 hours ago, mat_the_cat said:

I've had a look through the bits, and have possibly spotted the failed bearing...

That's fairly conclusive then! Also I was right about glympsing the heat damage to the layshaft and input pinion. It doesn't photograph very well, but although negligible wear you can see the purple tinge indicating it's been softened.

Hopefully in a week's time I'll have the replacement, and be able to make a start fitting it.

I'd be cautious about writing the gear off; the pic's not great but I can't see any seizing or spalling which I'd expect in a box that's run dry, the gear would have a tint anyway as heat treatment is applied to near on all gears. You could test it by trying to centre punch the end of one of the teeth, if it's been overheated you should get a decent mark and vice versa.

[Jikovron]

I had the exact same thing happen to mine , an lt77s which had the r380 gears with the intermediate type synchro rings, the oil ran low over a few months and it gradually got noisier 

The Input shaft had the same blue tinge so I binned it all as I didn't want a potential tooth weakness just waiting to show up catastrophically , not only did they get mega hot but also the casing had a blue haze around the bearing! , ended up fitting an sd1 2.4 diesel gearbox in its place which also leaked oil so investigating transit 2.4 gearboxes currently as they have normal ratios compared to the 2.5 Di 

[Puglet]

 New/old gearbox being removed after they found that the input shaft was causing issues 😞

[mat_the_cat]

On 7/10/2023 at 1:05 AM, somewhatfoolish said:

I'd be cautious about writing the gear off; the pic's not great but I can't see any seizing or spalling which I'd expect in a box that's run dry, the gear would have a tint anyway as heat treatment is applied to near on all gears. You could test it by trying to centre punch the end of one of the teeth, if it's been overheated you should get a decent mark and vice versa.

Depending on the hardness of the punch it would leave a mark on even good gears, as they'll only be hardened to around 40 HRC, and a decent punch will probably have a tip around the 60 mark (although the body will be softer/tougher.

The parts will almost certainly be shot blasted after heat treatment, removing the tint (we used to do the process in a previous job).

I was planning to collect the replacement 'box this weekend, but @Talbot kindly offered to collect and bring it up with him before Shitefest. Even better, he seemed strangely keen to assist in the fitting! We swapped a few parts over, and got it in place by midday Friday, after a lot of jiggling.

But guttingly, trying to turn the output shaft I found it was locked solid! Turned out that the input shaft was too long, and the splined part was binding up on the crank I did briefly consider taking a flap disc to it, but fortunately I was convinced to see sense!

I think the only course of action is to strip down the gearbox and get the shaft modified.

[somewhatfoolish]

Stick a washer on each bell housing bolt hole. 😁

[camryv6]

Grind it down it will be fine. just don't get it too hot

[mat_the_cat]

I have considered that, but pretty sure I wouldn't be able to grind a suitably circular bearing surface, which is still concentric to the splined surface. If it'd just have been a case of lopping off the end for clearance then no question, but the currently splined portion needs to engage into the crank.

[Mr Pastry]

8 hours ago, mat_the_cat said:

I have considered that, but pretty sure I wouldn't be able to grind a suitably circular bearing surface, which is still concentric to the splined surface. If it'd just have been a case of lopping off the end for clearance then no question, but the currently splined portion needs to engage into the crank.

Is this possibly an issue with the spigot bearing, rather than the shaft?