Series 3 Has anyone fitted a diesel gearbox to a petrol sIII?

What it says above really,

I collected my new rolling project yesterday, a 1981, 2.25 petrol, SIII who has affectionately named (by my partner) Wendy. The first issue I want to address is...

She has a noisy gearbox in reverse, 1st, 2nd, and 3rd. 4th is fine and all gears, both boxes and overdrive work great with no jumping out of gear at all even off road descending steep stuff in low. Im lead to believe its likely bearing related. (main lay shaft bearing?) I know bearing kits are available fairly inexpensively for this box so that not too much of an issue. I have a local guy in mind to rebuild the box for me, as Im a newb to land rover ownership and maintenance, currently its a little out of my skill/tool range.

However, someone I know who has previously owned an SIII mentioned fitting a gearbox from a diesel as it has more favourable ratios than the petrol one? Just wondered if anyone on here had any experience of such a mod? If not I think I'll keep it original and just have mine re built.

Any help or (experienced) advice very gratefully received.

Aren't they all the same?

Rodeo Joe said:

Aren't they all the same?

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I think all the LT76 boxes are the same regardless whether they were in a petrol or diesel model. Possibly some early boxes had different ratios in 1st and 2nd but not so much as you'd notice. 4th was always 1:1.

wireman said:

I think all the LT76 boxes are the same regardless whether they were in a petrol or diesel model. Possibly some early boxes had different ratios in 1st and 2nd but not so much as you'd notice. 4th was always 1:1.

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Thanks guys, that's what I was after. Rebuild mine it is!

They're the same. They all whine; it's a 30 year old gearbox. Suggest you do an oil change and see what drops out. Thanks

I had heard that military spec vehicles had different gear ratios but I've never seen any hard evidence. My diesel seems to go better than anything I read on here; purrs along at 45, slightly more noisy at 50 and will still cruise happily at 55. Is there something wrong with it?
Billy McNab - for that's its name - started its military career in 1984 as a 2 1/4 petrol. A later owner fitted a very good 3-bearing diesel which I am about to change for the correct 5-bearing petrol - albeit with a weber carb and electronic ignition.

[QUOTE="Old Seadog, post: 4459452, member: 88255. Is there something wrong with it?.[/QUOTE]
Broken speedo?

Rodeo Joe said:

[QUOTE="Old Seadog, post: 4459452, member: 88255. Is there something wrong with it?.

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Broken speedo?[/QUOTE]
Hah! Nope, I'm in line with other motorists in speed limit areas and the occasional signs telling you your speed agree with my speedo.