6-Speed Gearbox

[Doggy]

Thought it was about time I started a dedicated thread.

To recap, thanks to jonsowman, I managed to snap up a 20MB04 6-speeder from a late 2003 C5 last weekend. Collected it from a breaker in Maidstone this afternoon. It's currently resting in the back of the pug while we stop off to visit our daughter in St Albans.

Tis a hefty lump, (the gearbox), haven't a clue how I'm going to get it out of the boot, much less installed and working.

Oh well, one step at a time..........

[lozz]

Thought it was about time I started a dedicated thread.



Tis a hefty lump, (the gearbox), haven't a clue how I'm going to get it out of the boot, much less installed and working.

Oh well, one step at a time..........

Have a few Rag pudding's /bowl of weetabix, youl be ok mate,


iwill be watching this thread, sounds very interesting,
good luck with the work,

[steve_earwig]

haven't a clue how I'm going to get it out of the boot

Open boot, drive away very quickly. Simples

Wasn't there someone last year that had a crack at this but hit some major compatibility issue and disappeared? Or was that on a 110 and the 2.2 is a whole different ballgame? Or did I imagine it?

[lozz]

the 6 speed conversion can be done on the 110
someones done it on another forum, it involved some Drilling /tap n die work, for the speedo sensor etc iirc .

someone did look into it on here but gave up ithink, carnt rember who it was,

[steve_earwig]

someones done it on another forum

Link please!

I don't wish to pour wotsit on your doo.dah here D but are you doing this purely to see if it can be done or are there going to be some distinct advantages viz-a-v fuel consumption etc.? Any idea of figures?

[lozz]

it was on one of the 306 forums,carnt rember which one mind, it was a while ago iseen it

[Doggy]

I don't wish to pour wotsit on your doo.dah here D but are you doing this purely to see if it can be done or are there going to be some distinct advantages viz-a-v fuel consumption etc.? Any idea of figures?

The first 4 cogs are the same, 5th's a bit lower & 6th a decent amount higher.

With the standard 205/60/15's 5th becomes 28.8 mph/1000 as opposed to the original 31-ish, 6th works out at 34.5 mph/1000.

I believe that will deliver quieter, more relaxed cruising, I'm hoping for 2-3 mpg more and 5th will become a better overtaking gear, ideal for 60 mph upwards.

[steve_earwig]

Fairy nuff I remember when it was 5 speed gearboxes everyone wanted, I put one in a Cortina (which was then pinched ). It's a shame you can't just stick an overdrive on it. Or two maybe, one for each... nah, that's mad

I'm off for a Google...

[jasper5]

Can I just throw a little caution into this situation?

Have you considered the clutch and flywheel compatibility?

When I changed the flywheel and clutch in my 407 2.0 136, the clutch and flywheel were huge compared to the clutches and flywheels I've replaced on the 406s.

When I was trying to locate the new flywheel and clutch the mate of mine at thye dealers said there were a couple of different flywheels and clutches fitted to my 407.

I wish you every success with this Doggy, but please think about the clutch and flywheel.....of course it may not be and issue with the 2.2

At 70mph on the motorway in 6th gear the revs are 2,100rpm.

I have some pictures somewhere of the flywheel, clutch , and gearbox.

[Doggy]

Hi jasper. Yes, I did some homework. I have the VIN no.s for mine and the donor citreon, (VF38E4HXF81586206 & VF7DE4HXG76456218). If Servicebox & the cistern equivalent are to be believed, both cars have the same crankshaft assembly, flywheel, clutch and (I think) slave cylinder. The C5 doesn't have the driveshaft speed sensor, but seems to have provision to mount it......





One of the guys on the coupe forum has already done it, http://www.406coupeclub.org/PHPBB3/view ... 22&t=42765

I may still wimp out and sell it on..........

[nutski]

I may still wimp out and sell it on..........

If you decide to let me know, im still trawling everywhere to find another one

[Doggy]

See one's turned up in Poland.
http://allegro.pl/skrzynia-biegow-citro ... 07456.html

Just noted an error my earlier gearing calculation, overall ratio in 5th as standard is 30.7 mph/1000

6th with 205/60/15's is 34.9 mph/1000

[steve_earwig]

Soooo, how long before you stop doing maths and pull that cover off the final drive housing to see if has a drive gear for the speedometer transducer?

[rwb]

Compiled from cars-data:

Code: Select all

                   407   406   406
                   2.0   2.2    90
1th gear ratio    3,42  3,42  3,46  
2th gear ratio    1,78  1,78  1.87
3th gear ratio    1,12  1,12  1.15
4th gear ratio    0,80  0,80  0.82
5th gear ratio    0,65  0,61  0.66
6th gear ratio    0,53
Gear Ratio (end)  4.18  3.94  4.06

406: 120kmph @ 2400rpm [31mph per 1000] (2700 for the HDi 90 [27.6mph per 1000])
407: 120kmph @ 2100rpm [35.5mph per 1000]
(120kmph = 74.5 mph)

If I've used the calculator correctly, the 407 box in the 406 gives 120kmph @ 1750rpm [42.5 per 1000].

What I also noticed is that the 110 and 2.2 have the same gearbox (i.e., different to the 90) but have different 'end' ratios: 4.06 resp. 3.94. Therefore in effect the 2.2 has longer gearing.

[Doggy]

Soooo, how long before you stop doing maths and pull that cover off the final drive housing to see if has a drive gear for the speedometer transducer?

It fits round the driveshaft........