Hi all.
Can any of you brainy tech peeps let me know if it is a hard job to convert my mk1 345 to having
a five speed gear box. Something i might think about.
Cheers Mark.

Easy job.
remove the central driveshaft (slide off), remove 2 secondairy driveshafts (6 allens or hex bolts), remove shifter-axle from gearbox, remove 4 bolts and the whole thing drops.

Reinstalling is opposite of removing.

make sure you buy a 5-speed box INCLUDING diff because the 4-speed diff doesn't fit the 5-speed diff (longer neck).

And if you want to put new oil in either one, remove FILLER plug FIRST, it tends to get really, really stuck and you don't want to get oil out if you can't refill it...

Hi all.
Would a 360 gear box do the job or does it have to be 340?
Cheers Mark.

Can be either 340 or 360. Gears in every 5-speed are the same.

For a 360 box, you have to change the propshaft coupling, which is connected by only a couple bolts.
Adds about 1 minutes 24 seconds to the process

Hi Lads.
Cheers for that but are the prop shafts longer on a 4 speed.
Cheers Mark.

340 uses a longer diff rather than longer prop, why didn't they just do the same with the 360?

Speedy88 wrote:340 uses a longer diff rather than longer prop, why didn't they just do the same with the 360?

The 360 is meant to 'better' with the torque tube and no nasty coiling up of the components as the high power 340 guys have, but it does add alot of extra weight.

Mark, the 360 diff will be a lower ratio, meaning harder for the 1.4 to drive the car, but not sure how much difference it would make. Personally I wouldn't bother unless you break the 345 diff, I broke mine, they are weaker before 1982, but then I was trying hard. I don't think it will save as much fuel or quieten the car as much as a valve grind will. Those valve seats are pretty soft I think.

Edit to say - Strangely the B200E hatchback diff is 3.64:1, which is the same as the 84-on B14 diff. Your 345 diff is 3.91:1 apparently. So I'm saying its probably fine, but I still wouldn't bother. (presume you're eyeing up you old gearbox+diff from the GLT)