Series/Defender parts interchangeability

[Gab250]

wondering what can be swapped around between Defenders, and Series IIA and Series 3 Land Rovers in particular. I've got a few specific questions:

Are doors interchangeable between models? Are defender doors better if so?

What about dashboards/instrument panels?

Engines? Gearboxes? Diffs? Wheels?

Cheers, Gab

[JDNSW]

wondering what can be swapped around between Defenders, and Series IIA and Series 3 Land Rovers in particular. I've got a few specific questions:

Are doors interchangeable between models? Are defender doors better if so?

The door dimensions are identical, and up to 1986* interchangeable - Perentie doors are virtually Series 3 doors. Lock positions and striker position etc do differ. But 1987 on doors are much thicker and require the outboard seats to be moved in and a smaller steering wheel if going into a Series. Series doors are much lighter, but have sliding windows vs the windup windows on Defenders. Later Defender doors are all steel, stronger, and have better mechanism than early Defender doors. Rear door, later Defender ones are all steel and probably stand up better, and are interchangeable, with the usual "stay and lock may need some fiddling.

What about dashboards/instrument panels?

Not really, although the basic structure is the same as Series 3. But speedo setup is different, and the electrics of the other instruments are different. And fitting Series instruments/dash to a Defender would almost certainly break ADR compliance.

Engines? Gearboxes? Diffs? Wheels?

Early Defenders sold overseas used a developed version of the Series four cylinder engine. These were never sold in Australia (only V8 and Isuzu were sold here before 200Tdi) but it means that fitting Series engines to a Defender is possible if not particularly simple. And again would break ADR compliance. Fitting the 200Tdi to a Series 2/2a/3 is fairly simple, but the Series gearbox is not likely to stand up to it for too long unless treated carefully.

Early Defenders sold here used a LT95 four speed gearbox with combined transfer case (also used in Series 3 Stage 1 V8 & Isuzu), and this was followed by several related five speed boxes with a separate transfer case. All of these used constant four wheel drive where the Series transfer case is part time (except 1948-50), meaning serious changes need to be made to either the transfer case or the front axle to use these in a Series. And the Series gearbox/is not robust enough to use with most Defender engines.

The differential centres used in Series Landrovers were retained basically up until the end of Defender production for the front axle and for the rear axle of short wheelbase Defenders, so the diff centres will actually fit but all Series except Stage 1 (and some 1948) used a ratio of 4.7:1, where Stage 1 and Defender used 3.54:1. Also, later Defenders ,I think, used 24 spline centres where earlier used 10. Long wheelbase Series from very late 2a and Defenders until fairly late used Salisbury rear axles where the diff centre is built into the axle. These are not interchangeable (even apart from the ratio) as Series has leaf springs and Defender coils.

Axle housings are not interchangeable - Defender ones are about 50mm longer, and again, there is the leaf/coil difference.

Steel wheels are basically interchangeable between all Series and Defender models. But note that the load carrying capacity differs between long and short for some wheels. Also, several different offsets were used and although they will probably work for any Series/Defender, if putting some on a Series you may find the tyres are beyond the mudguards, and steering stops may need to be adjusted, impacting turning circle.

Alloy wheels - some are interchangeable, some are not - later ones are likely to not fit over brake drums.

Cheers, Gab

Other parts. Perhaps worth noting that Series 3 rear drum brakes are the same as early Defender. And there are numerous small bits and pieces that are interchangeable. But nothing from suspension and steering.

*I have, for convenience included the pre-Defender coil sprung Landrovers as Defenders. These were produced from 1983-1989, but only long wheelbase (110 or 120) and 6x6 were sold in Australia, and only with the V8 or the Isuzu diesel. Renamed as the Defender, with the introduction of the Discovery, and with the 200Tdi engine from the Discovery, these were absent from the Australian market until about 1992.

[p38arover]

Defender front bumper will bolt straight onto a S3, the bolt holes line up. However, there is no hole for the crankhandle.

Earlier Defender Indicators, brake, and park lights with flyleads should fit. Later lights have a socket for a plug.

You can fit the later lights or LED versions with this adapter cable:
Lighting Harness Adaptor, 3-Pin - KLR Automotive (https://klrautomotive.com.au/lighting-harness-adaptor-3-pin/)

JDNSW would know for sure but I expect wheel bearings RTC3429 and seals RTC3511 to be interchangeable.