Thread: Upgrading To A 5 Speed

Fitting a five speed gearbox to a Series Landrover is one of those things that "yes, you can do it, but it will be a lot of work and cost a lot of money". Basically, you have to either change to a different transfer case as well as gearbox, with substantial modifications all round such as gearbox mounts, engine adapter, handbrake problems, different prop shafts, new floor/ transmission tunnel etc, or, fit a later landrover box and transfer case, but these are all full time four wheel drive and thus you need to modify either the transfer case or the front axle, and you still have things like gearbox mounts, handbrake linkage, possibly engine adapter, floor and transmission tunnel etc.

By far the simplest is to fit an overdrive. These are available new and are easy to fit. Be wary of second hand ones unless you know exactly what you are doing - the most common Fairey ones are fairly fragile unless looked after, and although parts are available, they are not cheap, and you can soon find yourself regretting not getting a new one.

Your six cylinder engine should be OK without fuel additive as it has steel valve seats from new. Be very careful to ensure that exhaust valve tappet clearances are checked regularly, as they have a tendency to burn valves if this is not done. They are a nice engine to drive if properly maintained, but are thirsty, and do not stand up to abuse as well as the four.

Six cylinder 2as (with original engine) are getting quite rare (never were all that many - Series 3 much more common), and you may want to think about a full restoration to original specification rather than modifying it.

John

I thank you for the time and information that you have given me. Have been most helpful.

Originally Posted by JDNSW

Fitting a five speed gearbox to a Series Landrover is one of those things that "yes, you can do it, but it will be a lot of work and cost a lot of money". Basically, you have to either change to a different transfer case as well as gearbox, with substantial modifications all round such as gearbox mounts, engine adapter, handbrake problems, different prop shafts, new floor/ transmission tunnel etc, or, fit a later landrover box and transfer case, but these are all full time four wheel drive and thus you need to modify either the transfer case or the front axle, and you still have things like gearbox mounts, handbrake linkage, possibly engine adapter, floor and transmission tunnel etc.

By far the simplest is to fit an overdrive. These are available new and are easy to fit. Be wary of second hand ones unless you know exactly what you are doing - the most common Fairey ones are fairly fragile unless looked after, and although parts are available, they are not cheap, and you can soon find yourself regretting not getting a new one.

Your six cylinder engine should be OK without fuel additive as it has steel valve seats from new. Be very careful to ensure that exhaust valve tappet clearances are checked regularly, as they have a tendency to burn valves if this is not done. They are a nice engine to drive if properly maintained, but are thirsty, and do not stand up to abuse as well as the four.

Six cylinder 2as (with original engine) are getting quite rare (never were all that many - Series 3 much more common), and you may want to think about a full restoration to original specification rather than modifying it.

John

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Diana

Originally Posted by JDNSW

By far the simplest is to fit an overdrive. These are available new and are easy to fit. Be wary of second hand ones unless you know exactly what you are doing - the most common Fairey ones are fairly fragile unless looked after, and although parts are available, they are not cheap, and you can soon find yourself regretting not getting a new one.



John

These new overdrives of which you speak, do you have a web address for a supplier?
Regards,
Tote

Originally Posted by The Ducks Nuts

I am wanting to rip out the 4 speed and throw a 5 speed in the old girl. Will i need to change the diff as well ? Also I have been told that i will kill the motor if i run UL Petrol in her without an additive is this true ? She has a 6 in her which runs really well and id like to keep it that way which is why I'm asking about the fuel. <snip>....

D....Nuts

You have posted a number of questions asked by owners new to Series Land Rovers, so do some searches and you will find a few threads on the issue.

Regarding the 5 speed option, it depends which 5 speed you are planning to use. I have seen numerous conversions using alternate/mated engines but not many using the original Rover six cylinder.

Ashcroft transmissions in the UK do a 5 speed kit, where you can use a Land Rover 5 speed from a classic Range Rover or Land Rover 90 Ashcroft Transmissions Series 5 speed kit although that is usually done with a 4 cyl or even a 200TDi so I'm not sure about fitting the gearbox to the Rover 6 cyl engine although it can be done if you want to do the engineering yourself.

John's suggestion of an overdrive is the easiest and most simple choice. I avoid the early Fairey overdrive which had a poor reputation relating to failure. The RockyMountain rover-drive ( http://www.roverdrives.com/Model%20SX2.htm *) is an epicyclic box which is very quiet, strong and reliable, but expensive to purchase. All the overdrives will prevent you using the rear PTO.

Another option is to use a High speed transfercase (also from Ashcroft in the UK) Ashcroft Transmissions Hi Speed Series Transfer kit which increases the ratio of the high range but leaves the low range ratio the same.

With either of the above you don't need to change the diff ratio.

They will all cost you significantly more than you paid for your vehicle.

I use an upper cylinder lubricant in all my older engines, some people even use a splash of diesel in each tank as a cheap alternative to Flash Lube or it's equivalent.

Diana

* MR Automotive in Queensland are Australian Agents for Rocky Mountains parabolics so likely to be a good point of first contact.