D2 TD5 T Box in Defender?

Hi Everyone

Sorry - I think this is a well worn conversation but vert grateful for everyones thoughts.

A mate ha been persuading me to put his spare Disco 2 TD5 T Box in my 2006 TD5 Defender (heavy beast with lots of kit and occasional caravan towing).

Long story short, I have ti return my vehicle to garage for oil leak to original T Box. Garage did not fix it so they will have to drop the box again. Perfect opportunity my mate says to put his free disco 2 td5 box in for lower revs on Motorway etc etc. My vehicle is a very smart truck with little off road use. Its a bit of a Chelse Tractor (sorry!!).

Any thoughts - should I put the Disco T box in? I suggested it to my very experienced LR mechanic first time around and he said don't mess with it - it wasn't designed for that vehicle so don't mess. However there seem t be a lot of arguments FOR the swap.

Cheers

Angel

If you tow with it don’t expect fast getaways from standstill.
Easy enough job to change & try out while the other transfer box gets rebuilt.

Angel_110 said:

Hi Everyone

Sorry - I think this is a well worn conversation but vert grateful for everyones thoughts.

A mate ha been persuading me to put his spare Disco 2 TD5 T Box in my 2006 TD5 Defender (heavy beast with lots of kit and occasional caravan towing).

Long story short, I have ti return my vehicle to garage for oil leak to original T Box. Garage did not fix it so they will have to drop the box again. Perfect opportunity my mate says to put his free disco 2 td5 box in for lower revs on Motorway etc etc. My vehicle is a very smart truck with little off road use. Its a bit of a Chelse Tractor (sorry!!).

Any thoughts - should I put the Disco T box in? I suggested it to my very experienced LR mechanic first time around and he said don't mess with it - it wasn't designed for that vehicle so don't mess. However there seem t be a lot of arguments FOR the swap.

Cheers

Angel

Click to expand...

it wasnt designed for that vehicle ?thats tosh but 1.2 ratio with tall wheels will make it a tadge too high geared.
the disco 2 t/box differs only in that tmay not have a diff lock and rearoutput housing wont have a hole for the speedo drive,you have to swap the rear output for a housing that does, but the housings have a raised spigot which effects the center diff bearings preload, you either reset the diff shimming in front housing or find a rear housing with a spigot that measures the same as the one you removed

Jamesmartin makes a really important point. If you are fitting the full T Box rather than just adjusting the gearing to 1.2 then make sure it has a Centre Diff Lock otherwise your posh Defender will get stuck if even one wheel loses traction. You may not offroad much, but this will also affect its ability on road in the snow, or even on damp grass. (Afterthought Edit: unless your TD5 has TC. Does a 2006 TD5 Defender have TC?) It may also seriously reduce the attractiveness and therefore value of your truck.
Assuming it has a CDL it depends what you want to do with it. If you have not already lowered the gearing with big tyres, have a remap of some description and do a lot of motorway driving, then there is some decent benefit. Bottom line acceleration will be worse - and avoid compensating with more throttle unless you have a means to accurately monitor engine temp to prevent over temping when towing - but the cruise performance will be better with lower revs at motorway speed. You will also have to consider your speedo reading vs reality as it will be under reading and you should know by how much.

Thanks Everyone. I think I'm going to go for the swap. I'm too precious about my truck to do any serious off roading and only tow up and down the motorway a couple of times each year at most.
I run standard tyre size I think (265 75 16), it has a stage 2 remap. The spare T box does have a diff switch.

Have said to my mate that if I'm not happy after 500 miles, we'll swap it back again.

Thanks all once again for the good tips and advice.

Can you not just swap the transfer case gear drive cog to give lower revs in top gear. ?

Hi All

thanks for all the advice. I went for the swap in the end and it’s now much more of a pleasure to drive on the road. Significant increase in range through gears, significant reduction in noise, marginal loss of power but that might be because my new turbo hasn’t been increased as it’s still bedding in.

great mod

cheers all