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Changing LT230 transfer box


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I have sourced a S/H Disco transfer box from a fellow French enthusiast with a ratio of 1.222 for the 110 and wanted to find out how to confirm the ratio of my existing box as the sticky label has long since departed. Also I feel sure that the new disco box will bolt straight on but is there anything else that will need doing in terms of adaptation etc.

thanks

Ged

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If there's any doubt, Ashcroft have identification instructions here

http://www.ashcroft-transmissions.co.uk/category_4.html

The LT 230 was fitted to all 5 speed Defenders, all Discos and the RR Classic upto 1988. The serial number will be stamped in one of 2 possible places, either on the bottom left of the main casing or on the earlier vehicles right at the bottom of the left hand side face of the main casing obscured by the exhaust pipe in which case you will need a knife (to scrape the muck off) and a mirror. You are looking for Eg. "28D123456E, we are interested in the first two and the last, i.e. we call this a "28E".

(TIP: I actually found it easiest to use some thin paper and a pencil and take a 'rubbing' of the number)

& what they mean here

http://217.34.53.228:9876/uploads/230sno.wmv

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I've had a gander through the dirt under the box and the serial number starts with 22D so looking at the Ashcroft guide I think that confirms your answer Ralph.

I'm getting a box with a 1.222 ratio off a Disco so hoping that will improve the top end for motorway driving - which I do a lot of. I'm guessing it should bolt straight on with no mods.....am I right? Also what happens with the speedo drive? Do I keep the one in the new box or put my existing one in?

Ta,

Ged

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Having not done a transfer box swap myself, I think it's fairly straight forward to do, I'm sure some of the others on here will give advice,swap your existing speedo drive gear into the new transfer box, it needs to match the tyre size, see the list in the tech archive 'speedo drive gear' in the search box will find the thread.

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Replacing an LT230 transfer case leaving the gearbox in place. There are different input gears, so make sure you have the right one. Whenever I've had to buy a gear I've been asked how many teeth the old one had. I'm not sure if this relates to the input shaft or the gear teeth themselves though.

http://forums.lr4x4.com/index.php?showtopic=14601

Les.

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Guest diesel_jim

^^^^^^^^

but as long as you just have the "complete" transfer box then there's no need to play with the internal gears, just slide it off the old main box and slide it onto your current one.

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Having had a look at the Ashcroft blurb they say that changing from 1.410 > 1.222 gives a raise of 15.38% so I suppose that equates to a increase of speed of 15.38kmh at 100kph at the same engine revs or conversely a drop of 15.38% engine revs for the same speed. Overall that does not seem too bad and should take some of the strain from the engine on longer runs as well as perhaps reducing overall noise. Lets just hope the new transfer box is not the oil-leaking bucket of poo that my current box is!

Ged

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