T25 diesel gearboxes

[sabbottage]

I have just become the proud owner of a 1989, 1.7diesel transporter. It has been fitted with a 5 speed box which turns out to be from a petrol model.....hence 55mph flat out!!!!!! Can anyone tell me if it is possible to change just the diff and if so can it come from the early 80's passat. Or what is the box code for the one with the highest diff ratio. Any info much appreciated as I am in the wilds of southern France and my language skills don't extend to high tech discussions on gearboxes. Thanls in advance STEVE.

[BugsyMalone666]

ok im Semi new to T25`s as I have a bay and am sticking a T25 Diesel in it, basically with T2/T25 gearbox the bell housing removes from the gearbox, as basically when sticking the diesel in the bay you can just use a T25 bell housing on the stock bay gearbox.

The same would be true of the rest of the T25 range, where I have noticed one difference is the gearchange, so the question is did your T25 start life as a petrol and be converted to diesel or has someone fitted the box from something else?

are you positively getting all 5 gears? I really cant see that 55mph flat out can be all 5 gears, sounds more like 4th!I know most of the T2/T25 still dont rev a whole lot higher than a diesel, my bay is a 1600 and at 4000 is doing 65-70, the Diesel in a T25 is supposed to be governed to 4500 RPM.

Also are you running stock wheels/Tyres? that can make a big impact if you have lower profile tyres at the back.

I know someone else with a converted bay, its a diesel and they have used a 2litre petrol gearbox (4speed) and said that at 4500rpm they hit the govenor and thats about 90mph!

[Lozza30]

Hi did you end up putting a diesel in your t2?

[BugsyMalone666]

Hi did you end up putting a diesel in your t2?

Wow this is an antique thread! I barely come to most of the forums anymore, more FB groups, just because hosting photos is such a pain unless you want to pay.

Short answer is yes I did put a diesel in my T2, I want to say 2009 I started looking in to it, started with a 1.6d from a caddy/rabbit pickup, later moved to a 1.6TD from a mk2 golf and that was pretty good as it gave like 45mpg, I ran it on veg oil and all sorts.

Putting a diesel in a T2, I opted for 205/80/16 tyres to help with the gearing, T25/Vanagon bell housing goes straight on a T2 box, if you run a 1.6 box thats it, 2litre boxes you need to shorten the input shaft by 5mm. Starter motor you need to get creative, think I used a mk3 golf VR6 one, 1/2" thick adapter plate(home made) to fit it to the gearbox. You'll need a T25/Vanagon sump for the diesel to allow you to fit the engine, you'll also need the oil pump pickup, as its designed to sit at the 50degree angle. Engine mounts, well you can use a 1.6d or 1.6td as they are slightly different shapes to clear the turbo (I ended up building some as I had a turbo sump, but only NA mounts), but you'll have to build your own cradle to the chassis. 2x 1.3 golf mk2 radiators is plenty to keep a setup cool, with the right setup.

I'd probably not exactly do the diesel one again, I was going to look to go golf GTi, but after my TD engine failed (not related to putting it in a bus or the use of veg oil) I went back to aircooled and have stuck with it, if I had to go back I'd be looking for 2litre 8v counterflow engine, because I am fairly certain I could just throw it in exactly how I did with the 1.6diesel, only 115bhp would be plenty in the fan. Drawback of diesels is vibration, look out for Audi TDi Hydro engine mounts, they get rid of alot of it.

[Crasher]

It is a T3 for Transporter 3 and a type 25 so T3 t25.

[Lozza30]

Hello, this is definitely an antique thread. I didn’t expect a reply but i though it was work a good go!

What your van a 1.6 petrol originally?
What did you do in terms of gear box ratio, did you change anything? How did it drive being in a petrol box?



Many thanks

Wow this is an antiqued thread! I barely come to most of the forums anymore, more FB groups, just because hosting photos is such a pain unless you want to pay.

Short answer is yes I did put a diesel in my T2, I want to say 2009 I started looking in to it, started with a 1.6d from a caddy/rabbit pickup, later moved to a 1.6TD from a mk2 golf and that was pretty good as it gave like 45mpg, I ran it on veg oil and all sorts.

Putting a diesel in a T2, I opted for 205/80/16 tyres to help with the gearing, T25/Vanagon bell housing goes straight on a T2 box, if you run a 1.6 box thats it, 2litre boxes you need to shorten the input shaft by 5mm. Starter motor you need to get creative, think I used a mk3 golf VR6 one, 1/2" thick adapter plate(home made) to fit it to the gearbox. You'll need a T25/Vanagon sump for the diesel to allow you to fit the engine, you'll also need the oil pump pickup, as its designed to sit at the 50degree angle. Engine mounts, well you can use a 1.6d or 1.6td as they are slightly different shapes to clear the turbo (I ended up building some as I had a turbo sump, but only NA mounts), but you'll have to build your own cradle to the chassis. 2x 1.3 golf mk2 radiators is plenty to keep a setup cool, with the right setup.

I'd probably not exactly do the diesel one again, I was going to look to go golf GTi, but after my TD engine failed (not related to putting it in a bus or the use of veg oil) I went back to aircooled and have stuck with it, if I had to go back I'd be looking for 2litre 8v counterflow engine, because I am fairly certain I could just throw it in exactly how I did with the 1.6diesel, only 115bhp would be plenty in the fan. Drawback of diesels is vibration, look out for Audi TDi Hydro engine mounts, they get rid of alot of it.