Overdrive or Transfer Box 1997 300Tdi

Hi Folks

I've got a 1997 300tdi 90 and it would be nice to be able to cruise a bit better and go over 70mph (where permitted).

What are the options and how much faster will I be able to go? Its got plenty of poke as its had a large intercooler etc.

Is there a tranny box that will fit straight on?

Cheers all

yes, a 1:22 one from a disco, as opposed to the 1:44 one you will have fitted to your depender

bolts straight on

So no mods needed at all? How much quicker will it make it? Comfortably if there is such a word with a landy.

What is the model number I need to look for?

Cheers

Landy-Pilot said:

So no mods needed at all? How much quicker will it make it? Comfortably if there is such a word with a landy.

What is the model number I need to look for?

Cheers

Click to expand...

you might have to drill and tap a couple of 8mm threads into the casing, the locations of which are easy to centre - there's about a 15% difference in the gearing between the two boxes

no idea what the part number is, i tend to buy a gearbox and tranny box complete from a scrapped disco

oh you will have to swop the tranny brake cable bracket from your depender to the disco box, just nuts and bolts no quantum physics required

Thanks for your help I will start the search!

The advantage of the Overdrive is two fold. They split the gears giving better flexibility when towing and they don't change the overall gear ratios either so you get 'as designed' gearing when needed.
The disadvantage of the overdrive is that you lose the ability to use PTO equipment such as winches, pumps and compressors etc.

Your 300tdi will pull the taller disco gearing no problem. You probably won't find yourself going any faster, just a more relaxed drive without feeling like you're thrashing it.You should be able to pick up a disco transfer box for 50 quid or so. The big disadvantage of an overdrive is they are stupidly expensive even second hand.

stuck a disco tranny box on mine. 98 300 110 definetly more relaxed driving does in 4th what it used to in 5th.just unbolt handbrake backplate from box and swing out of way no need to disconnect cable. not sure about 90 but dont even need to disturb g box x member on 110