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Longer ratio gearbox for hdi - Printable Version

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Longer ratio gearbox for hdi - pugbug - 21-05-2015

I've managed to source a 206 HDI eco gearbox, supposedly this has a longer final drive, I use my 306 for motorway driving and hate the high revs...



The box coming out is 20TD95

The eco box is 20DM1, it looks as though it's hydraulic operated, I'm I right in thinking swap over the bellhousing from the 306 box to the 206 box and it should fit, they are both BE4 boxes. Also can anyone dig up the ratios of the boxes? Cheers.


RE: Longer ratio gearbox for hdi - Poodle - 21-05-2015

The ratios are identical, it's just the final drive that's different. It's been covered a few times, should come up with a search, got a feeling it's in a sticky or a guide somewhere too...

As you say, swapping the bellhousings should sort it right out.


RE: Longer ratio gearbox for hdi - pugbug - 25-05-2015

Swapping the bellhousing looks pretty tricky, esp without a reference. attempting to pull the box apart now.


RE: Longer ratio gearbox for hdi - pugbug - 25-05-2015

Waaaaaaaay waaaay to complicated, it doesn't appear as though you can just swap the bellhousing on these boxes, the only way I can see this done is taking out the fifth and swapping it over to the 306 gearbox.

Is there an easy way of just taking the internal out in one go and swapping it over from one box to another?


RE: Longer ratio gearbox for hdi - thododd - 25-05-2015

Not exactly easy but its essentially just a case of swapping the FD/CWP from the eco box into yours, it can be done using either differentials


RE: Longer ratio gearbox for hdi - Dum-Dum - 26-05-2015

For the love of god don't swap 5th as they are identical. It's the final drive that's different!


Sadly you need to swap the secondary shaft and the diff. if you swap just the crown wheel on the diff it doesn't mesh properly with the second shaft in the box so you need to have the box apart to swap both. Taking the box apart requires a few specialist tools like a special socket to get the nuts holding 5th gear off.


Swapping the 306 to hydraulic clutch is the easiest and only sensible option. "Grant" did this on a 306 XSi and has a thread and possibly a guide somewhere here.


RE: Longer ratio gearbox for hdi - welshpug - 26-05-2015

naah, easiest option is a berlingo/partner clutch cable and cable type arm.

the shafts can be swapped into yiur box easily enough, but it does entail the entire dissasembly of the box.

you can't really swap just the bellhousing as they are line bored.

nothing special about the socket, its just a 12 sided 28mm, a punch for the roll pins in the selectors


RE: Longer ratio gearbox for hdi - Poodle - 26-05-2015

My bad, thought the bell-housings were swappable.

Edit: misread your post, Mei, so all it needs to work is a cable and arm swap..?


RE: Longer ratio gearbox for hdi - welshpug - 26-05-2015

IF the 206 engine sits at the same angle, if not, then a full casing swap, output shaft bearing may need swapping too.


RE: Longer ratio gearbox for hdi - pugbug - 26-05-2015

And I thought this was going to be easy...! Theres a place not too far from me, who's willing to do the job. Swapping the diff looks easy, the casing visually looks identical.

it doesn't appear to be very labour intensive.

So just to confirm it's the entire second shaft and the diff that'll need swapping?

It's the only time I'll ever get a chance to do this, would be awesome cruising at motorway speeds with lower revs, over 80 and the revs are tooo high!


RE: Longer ratio gearbox for hdi - welshpug - 27-05-2015

slow down..


RE: Longer ratio gearbox for hdi - Dum-Dum - 27-05-2015

(26-05-2015, 09:56 PM)pugbug Wrote: So just to confirm it's the entire second shaft and the diff that'll need swapping?

Yes, you need to swap both the diff (or just it's crown wheel) and the second shaft in the gearbox. The HDi Eco crown wheel will not mesh with a standard 306HDi box. I know this, I've tried it.

Swap the bits operating the clutch is the easiest option.


RE: Longer ratio gearbox for hdi - pugbug - 27-05-2015

Nice one! Too complicated for me, the next nearest thing I've taken apart is a winch, which I found pretty tricky to put back together, so a gearbox is well out my league.

I hope it's not going to be too expensive...!


RE: Longer ratio gearbox for hdi - powerandtorque - 27-05-2015

If you can find one, I believe that a Xsara 110 HDi box is longer and a direct fit. I've never personally verified that though, merely going by what others have said.

However, that said, I'm surprised that you find a standard HDi box too short as for a 5 speed it's pretty long really - 70mph is about 2500rpm so hardly what I would call short. It's a fair bit longer than a 1.9 TD 'box for example.

(I'm doing about 20k miles a year in my 306 going up and down the M4 daily, so also doing plenty of motorway miles)


RE: Longer ratio gearbox for hdi - Ruan - 27-05-2015

I'd suspect a Xsara 110HDi box will be a Hydraulic BE4 box - same type as the 206 Eco box.

Don't quote me - but likely to be same type, but might be the right angle for the engine bay.


RE: Longer ratio gearbox for hdi - pugbug - 27-05-2015

Try driving a few of the modern diesels with a 6 speed box, huge difference in revs! Will have a word with the guy doing it, as I don't want to spend a great deal of money!


RE: Longer ratio gearbox for hdi - Ruan - 27-05-2015

Oh yeah, my v50 is doing 1900rpm or so at 70mph in 6th, but that's a 16v cylinder head and another 5 years of turbocharger technology - but the problem is, but not sure that these engines are actually breathing well and efficient enough at lower RPMs to pull it off and cause an decrease in consumption - I'd be interested to see...


RE: Longer ratio gearbox for hdi - pugbug - 27-05-2015

^ Yep has a VNT turbo, so by 1900 rpm it's probably already hitting the peak torque band.

So to those of you who have taken one of these boxes apart ,is it a very labour intensive job? I don't support the shaft will come out in one lump? As I'm not going to be doing it I don't want to pay well over the odds for it, if that's the case might as well scrap the idea altogether.

One other thing, slightly off topic. Found out the exhaust manifold and the exhaust to turbo manifold, differ by ~ 7mm I had my exhaust manifold machined out, should give a little better flow to the turbo!


RE: Longer ratio gearbox for hdi - welshpug - 27-05-2015

other than having to remove 5th gear from the input shaft yes you can remove both shafts pretty much complete to swap them into another casing.

there may be a difference with the output shaft outer bearing, but you can use the one from the BE3 shaft if needs be.

you will need to swap both shafts AND the diff over.


for someone that does transmissions day in day out it wont take long at all, I've had a few of them apart and with my two impact drivers and a punch I can have one apart in quite a short space of time.


RE: Longer ratio gearbox for hdi - toseland - 28-05-2015

(27-05-2015, 11:42 AM)Ruan Wrote: I'd suspect a Xsara 110HDi box will be a Hydraulic BE4 box - same type as the 206 Eco box.

Don't quote me - but likely to be same type, but might be the right angle for the engine bay.

from what i have read,  that box is 29mph per 1000rpm,  rather than 27 as is standard in the 306hdi's   i did do a lot of reading around about it and it just seemed like a lot of ballache to change it all over.


i was looking for a decent 6 speed,   the ML gearboxes apparently fit but the work is huge to get them completely compatible. 


RE: Longer ratio gearbox for hdi - pugbug - 28-05-2015

I remember reading on a forum a long while back that a 206 HDI hit 140 mph on the speedo! Not on a dyno or owt. I'm 1/3 of the way completing my engine change and manage to get the box out.

How the hell does the drivers side driveshaft come out???


RE: Longer ratio gearbox for hdi - HDi--Power - 28-05-2015

I'm beginning to think that you haven't got a blind clue what you are doing  Confused


Re: RE: Longer ratio gearbox for hdi - Seb_Ryan - 28-05-2015

(28-05-2015, 09:02 PM)pugbug Wrote: I remember reading on a forum a long while back that a 206 HDI hit 140 mph on the speedo! Not on a dyno or owt. I'm 1/3 of the way completing my engine change and manage to get the box out.

How the hell does the drivers side driveshaft come out???

2 11mm studs on bearing/engine mount

And why do you wanna hit 140mph? You wont be pugbug.. Youll be flatbug


RE: Longer ratio gearbox for hdi - pugbug - 28-05-2015

taken them out and still wont budge!


RE: Longer ratio gearbox for hdi - Poodle - 30-05-2015

(28-05-2015, 09:08 PM)HDi--Power Wrote: I'm beginning to think that you haven't got a blind clue what you are doing  Confused

Only now? Wink

Use a lever bar, a hammer and a chisel to encourage it to let go. You can smack the bearing protector that sits on the gearbox side of the bracket, personally i get better results from beating on the intermediate cv casing.


RE: Longer ratio gearbox for hdi - pugbug - 30-05-2015

lol all done! It didn't come out as easily as the passenger side one! I didn't want to yank it hard from the wheel side at the risk of damaging the boot!


RE: Longer ratio gearbox for hdi - Poodle - 31-05-2015

Yeah don't pull on the cv joint, you'll end with a driveshaft in three bits lol.


RE: Longer ratio gearbox for hdi - pugbug - 01-06-2015

Well this doesn't look like it's happening Sad

The guy doesn't want to do it, he said stripping two boxes down will be £££ plus he mentioned something about the selectors. ffs really wanted this! Ah well.