Defender LT77 gearbox advice.

Hello, I have recently done an N/A to TDI engine conversion using the original defender LT77 gearbox.. I like the ratio untill you hit 5th gear. Is it possible to take the box out and replace 5th gear with one out a disco LT77 ? Would it have a big difference ?

Thanks, Grant

It wont be as easy as changing one gear, if it is possible then you may have to change the layshaft to match. Sure JM will be here soon to cast his wisdom!

Ah ok, I am not to clued up on gearbox's. Thanks for the advise anyway I know where your coming from. Thanks again

What's up with 5th? Could just change to a 1.2 transfer box if you wanted a better drive

Just Max's out at 70 and is screaming, would rather it to just be a bit more calm and not feel like it's harshing it..I have a spare disco transfer, is that a 1.2 ? Thanks for the advise

what size tyres have you fitted??

You do 70? :what: I sit at 60 as its most comfortable for me and the engine. And yes as far as I'm aware a disco transfer box will be 1.2 and should be a straight swap.
Anyway they're not really designed to be pushed that hard and fast on the motorway, you won't find many on here that do that speed

Run 750's, will be going to 265-75 soon hopefully ( insa-turbo special tracks ) so won't be doing 70.. Haha I know I know even at 50-60 it's not the best. Might look into doing the transfer swap in summer, thanks both for the info so far

Yeh tranny box is straight swap takes a few hours nothing to bad..

my 200tdi 90 with 1.4 transfer box, 235/85 tyres will sit at 70. it sits at 70 all the 130 mile journey along the motorway from home to uni.

i will be fitting a 1.2 transfer box to drop the revs a bit though

have a look, you might have a 1.6 in atm

I doubt a 1.6 could do 70 lol my 1.2 disco box is reving hard at 75 that's on 265/75 mud terrains

MaxyMan said:

I doubt a 1.6 could do 70 lol my 1.2 disco box is reving hard at 75 that's on 265/75 mud terrains

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his speedo is probably bouncing between 60 and 70

early 110s did come with 1.6's though.. it could probably touch 70 downhill whilst screaming it's bollocks off

Hahaaa well and truly flat outtt

interesting this
I have the same at 60mph it feels like it needs another gear
Although any faster and the road noise from the tyres would be mental
id be deaf

Eh what was that love, I carnt hear you !!

Transfer box should have a sticker on the back stating the ratio, check if yours is defender standard 1.4 or as stated before the earlier ones had a 1.6 fitted to 110s. Discos have a 1.2 ratio transfer box which is quite a common swap for those who desire a more road friendly experience

the_wolf said:

Transfer box should have a sticker on the back stating the ratio, check if yours is defender standard 1.4 or as stated before the earlier ones had a 1.6 fitted to 110s. Discos have a 1.2 ratio transfer box which is quite a common swap for those who desire a more road friendly experience

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Hello, can't find any stickers.. Have a couple codes stamped on it.

HRC 1342
and
RC 6106

They is a two stamps witch have 83 with a circle etc round it.. It used to do 70 with the N/A in it but just exact same with the tdi in it aswell

Gwalk said:

Hello, can't find any stickers.. Have a couple codes stamped on it.

HRC 1342
and
RC 6106

They is a two stamps witch have 83 with a circle etc round it.. It used to do 70 with the N/A in it but just exact same with the tdi in it aswell

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look for the serial number, you might need to wire brush it.

The most I have had out of mine is 65 but its fitted with 235 A/T's but I am kind of hopeing when we put the insa special tracks on 235's it will do around 70 as the special tracks will be slightly taller than the A/T's so in theory will slightly step up the gearing if not mite go for the disco tranny box at a later date

Interesting!

Mine can do 70 fairly happily, though it is v noisy, so I tend to go about 65 ish, which makes it a bit quieter.

I'm pretty sure it doesnt have a disco transfer box in, but will check next time i'm underneath. Disco transfer is something i'm considering...