Converting 4 speed to 5

[Lawrence]

Hi fellows, i have a 4 speed box behind my td42. I am wondering if its possible to convert it to 5 speed by adding the gears and additional parts, The manual has the boxes as basically similar except than one has 5 speed and one has one less gear. Anybody ever done this, or think it is possible?

[big red]

over here the GQ was 1988 onwards and had the 4.2 litre TD42, all came with 5 speeds.

there is sometimes a difference in the model numbering between overseas and here.

this is my 1990 4.2 petrol GQ which has the TB42 and 5 speed ...







there is also my 1985 3.3 turbo diesel MK which has the SD33T and a 5 speed but the early ones had a 4 speed ...


And this is my 1999 4.2 turbo diesel GU which has the TD42T and 5 speed ...

[mickyd555]

I dont belive ive ever seen a red G60 Shane, when ya gonna get one of those!!!

[Lawrence]

Big red, your wagon really looks good. over this side of the world, some of the earlier gqs came with 4 speed. In the manual, they use the same parts except for the 5 speed gears.

[big red]

I dont belive ive ever seen a red G60 Shane, when ya gonna get one of those!!!

if i see a good one cheap i might get it

[Clanky]

You would need a new layshaft and a new output shaft, both gears for 5th, extension housing and other items such as bearings and circlips etc to convert the 4 to a 5.
Much easier to buy a complete 5 speed.

[Lawrence]

You would need a new layshaft and a new output shaft, both gears for 5th, extension housing and other items such as bearings and circlips etc to convert the 4 to a 5.
Much easier to buy a complete 5 speed.

Thanks, it would be much easier to buy a five speed box normally, but Patrols with 5 speed boxes are not really common here.

[Clanky]

I have a couple of 5 speeds here not doing anything, but they are really heavy and I reckon the freight would be pricey
what about civilian bus gearbox availability locally? Its the same box mostly.
This should give you the main parts (heavy parts) and then all you need for the Patrol is the aluminium extension housing to suit the transfercase, which would be relatively cheap to freight.

[Lawrence]

I have a couple of 5 speeds here not doing anything, but they are really heavy and I reckon the freight would be pricey
what about civilian bus gearbox availability locally? Its the same box mostly.
This should give you the main parts (heavy parts) and then all you need for the Patrol is the aluminium extension housing to suit the transfercase, which would be relatively cheap to freight.

Thanks Clanky, i suspect the freight cost would be a problem to this side of the world. We did have a number of Civilian buses here, which i know is the same gearbox. I just wasnt sure how they would do with the transfer case. Thanks for the info.