Roadster Rebuild Diary from Cornwall

[milliemarlin]

Re: Roadster Rebuild Diary from Cornwall

Gears are usually case hardened; adding carbon into the surface layer while retaining a tougher core. I wonder if the reverse gears are not hardened. They are unlikely to wear out.
Paul

[meverett]

Re: Roadster Rebuild Diary from Cornwall

Thanks Paul, do you think my reverse gear and idler have a few more miles left in them? The wear is only on a few teeth and only on the edges so teeth are still there. Cheers,

[b_caswell]

Re: Roadster Rebuild Diary from Cornwall

The problem that the wear will cause is the gear to possibly throw out under load.

The only difference in the Spitfire and smaller Dolomite's single rail boxes is they have a shorter input/first motion shaft than the Ital/marina. Possibly different clutch spines.

[droverpete]

Re: Roadster Rebuild Diary from Cornwall

Spitfire - Dolomite - Marina. Most of the internals are interchangeable. I used the Dolomite main shaft in the Marina box to allow its overdrive to fit on the back. Seem to remember making one good box out of three. Still got a box of bits somewhere, if there are any reverse gears there you're welcome to them.
PeterH

[meverett]

Re: Roadster Rebuild Diary from Cornwall

Thanks for the replies guys, I have got a lead on 3 used marina gearboxes in my local area that could be potential for spares so I will check them out and follow up on this (take the top off each to check the teeth) May be a few spares for someone else when needed.

[milliemarlin]

Re: Roadster Rebuild Diary from Cornwall

Thanks Paul, do you think my reverse gear and idler have a few more miles left in them? The wear is only on a few teeth and only on the edges so teeth are still there. Cheers,

That’s the million dollar question. I can’t possibly say from just looking at the photo. As said it looks as though someone has tried to ram it into reverse while travelling forward. Could reverse be confused with 5th in a momentary lapse of reason?

Looking at the photo the wear seems to indicate that the damaged parts of the teeth are not in contact when the reverse is fully engaged so it would probably outlast the car. But if it doesn’t it is quite a faff to replace and it could damage the rest of the gearbox. It also looks as though it could impede engagement.

As a cautious chap I would tend to replace it and set my mind at rest.
Paul

[b_caswell]

Re: Roadster Rebuild Diary from Cornwall

Note the 1300 box has a different size clutch splines to the 1800 box on the input shaft.

[meverett]

Re: Roadster Rebuild Diary from Cornwall

Been pottering around in the garage and got my brake and clutch mounted in the bulkhead.
Made an aluminium reinforcing bracket. Will add some angle aluminium inside the bulkhead when I acquire some.
Also rubbed down and sprayed my standard shocks. Added the adjustable tie rods the other day.

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[meverett]

Re: Roadster Rebuild Diary from Cornwall

With a donor gearbox purchased for a bargain £10 from eBay and a trip to Exeter to collect and I have got the gearbox rebuilt.
Swapped the reverse gear, idler and laygear, new seals and gaskets and not forgetting the copper washer in the bell housing. Bit of paint and should be good to go. Selects gears nicely so must have gone back together correctly.

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[dcunn]

Re: Roadster Rebuild Diary from Cornwall

Good job with the box - the rest of the car ain't so bad either !

[meverett]

Re: Roadster Rebuild Diary from Cornwall

Thanks DC. Yours will be back on the road before mine.

[meverett]

Re: Roadster Rebuild Diary from Cornwall

Re: Marina / Ital gearbox parts.
Ok, now I have rebuilt this gearbox ready for fitting I thought it would be a good idea to fill up with ep90 oil and spin it over with the drill on the first motion shaft.
It was making a bit of noise in first gear (ticking) when the teeth are engaging. I have lifted the lid to inspect and tied it down to the reverse idler that seems to be slightly engaged when in first gear. All the other gears are quiet.
I have used the 17 teeth idler, 29 teeth hub on the 13 teeth laygear from the donor gearbox and all the other gears are the same between both boxes. The donor gears looked in good condition with no major wear.
Is this common on these gearboxes?

https://youtu.be/1YKLiNXjFNc

[greyV8pete]

Re: Roadster Rebuild Diary from Cornwall

Is the selector fork / detent in the correct position? From hazy memory I had a gearbox years ago (maybe TR3A?) and there was a spacer tube on the bottom gear selector shaft to prevent over travel of the selector fork. Peter.

[b_caswell]

Re: Roadster Rebuild Diary from Cornwall

Ive picked some brains on the TSSC forum and their opinion is that its a common problem even with recon boxes.
Caused by a combination of wear in the operating lever and idler.
I am not sure how much of the box needs to be dismantled again to get the reverse gear operating lever out of the casing. But the suggestion is note which way it works then put it in the vice and gently bend the bottom of the arm backwards. Just a little at a time until it clears the mainshaft gear.
Hope this helps and I will report back to the Triumph boys.
Ben

[meverett]

Re: Roadster Rebuild Diary from Cornwall

Ok thanks, I have just stripped it back down (I'm getting good at that) and compare the selector fork and other bits with the donor gearbox parts. Will report back.