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Re: 6-Speed Gearbox

Posted: Thu Dec 12, 2013 1:33 am
by Frenzy406
Hey Doggy great to hear you managed the conversion !
I managed to add a 20MB04 'box to my collection of mods to finish rebuilding my car...
Just have to find the time to finish it off ! Been off the road too long now ;(
...altho looking at ur pics of the speedo drive gear transfer ... i'm thinking I Could also do with popping an LSD in there while i have the diff casing off, as it always had 1 wheel spinning if steering at all in in 1st or 2nd ...
Ok now I need to find more cash :o

Re: 6-Speed Gearbox

Posted: Wed Dec 18, 2013 2:27 am
by munkymanmatt
So I take it that putting a 6 speed box into a D8 is all but impossible?
I would definitely benefit from one as I'm doing about 800 miles per week, 500 on motorways :(

Re: 6-Speed Gearbox

Posted: Wed Dec 18, 2013 11:53 am
by Bailes1992
munkymanmatt wrote:So I take it that putting a 6 speed box into a D8 is all but impossible?
I would definitely benefit from one as I'm doing about 800 miles per week, 500 on motorways :(
Nothing is impossible!
You will need to convert to a hydraulic clutch.
You'll need the gearbox from the 407/C5 and clutch, flywheel and drive shafts from the 2.2 HDi.

You'll also have to work out the RPM signal but I can't see that being a big issue!

Re: 6-Speed Gearbox

Posted: Wed Dec 18, 2013 3:32 pm
by madmadmax
munkymanmatt wrote:So I take it that putting a 6 speed box into a D8 is all but impossible?
I would definitely benefit from one as I'm doing about 800 miles per week, 500 on motorways :(

you could look at the bolt pattern for the bellhouseing to gear housing then you would not need the clutch and stuff, just the gasket if they mach up. but thats getting abit more complicated

Re: 6-Speed Gearbox

Posted: Wed Dec 18, 2013 5:05 pm
by Bailes1992
madmadmax wrote:
munkymanmatt wrote:So I take it that putting a 6 speed box into a D8 is all but impossible?
I would definitely benefit from one as I'm doing about 800 miles per week, 500 on motorways :(

you could look at the bolt pattern for the bellhouseing to gear housing then you would not need the clutch and stuff, just the gasket if they mach up. but thats getting abit more complicated
The bolt pattern is identicall.
The main issue is the 1.9TD has a cable clutch where as the rest of the 406 range don't!

Re: 6-Speed Gearbox

Posted: Wed Dec 18, 2013 9:14 pm
by Doggy
Don't want to rain on your parade, but I don't think a standard 2.2 would pull 6th comfortably - even with 235 lb/ft, so I really can't see a 1.9 hacking it.

Re: 6-Speed Gearbox

Posted: Wed Dec 18, 2013 11:40 pm
by munkymanmatt
Right so no point doing it until I need to change the clutch.
Sounds fairly complicated altogether!

gearbox off a 2L HDi 407/C5 and clutch/flywheel/driveshaft off a 406 2.2 hdi? or the 407/C5 again?
plus labour as there's no way in hell I'll be doing it myself. Can do small jobs myself but this is way out my league.

Doggy I would only be using it on motorways, 75mph+ where the engine is doing plus of 3k revs in 5th I reckon the 1.9 could cut it as long as I go fast and I've no problem doing that :P Could always screw it a bit if she's struggling anyway.

Re: 6-Speed Gearbox

Posted: Thu Dec 19, 2013 7:53 am
by Bailes1992
306 HDi gearbox would bring it down by about 500rpm and still has a cable clutch!

Re: 6-Speed Gearbox

Posted: Thu Dec 19, 2013 11:02 pm
by Doggy
Bailes1992 wrote:306 HDi gearbox would bring it down by about 500rpm and still has a cable clutch!
I was thinking along those lines too.
IIRC my bro's 1.9TD was about 28 mph/1000 in 5th, (as was my '99 Xsara HDi 90), a 110 HDi 406 is about 31 mph/1000, BUT it's probably got similar ratios and a higher final drive.
Having driven a few 405 TD estates, I remember being impressed how well the 1.9 lugs the bigger 406 estate, but I strongly ssupect that means Pug have got it just right as standard, tinker at your peril.

Be careful with 407 6-speed 'boxes. 407's have 17" wheels, hence lower gearing to compensate......

Re: 6-Speed Gearbox

Posted: Thu Dec 19, 2013 11:20 pm
by davew
anyone know if a 20MB02 6spd gearbox will fit a 406 110bhp there seems to be loads of them around fairly cheap.

Re: 6-Speed Gearbox

Posted: Thu Dec 19, 2013 11:35 pm
by munkymanmatt
Bailes1992 wrote:306 HDi gearbox would bring it down by about 500rpm and still has a cable clutch!
I assume this means it would be a much easier swap than having to put in a hydraulic clutch too?

but even then I'd still have to change flywheel and driveshaft right? Seems a lot of effort for 500rpm less!

Re: 6-Speed Gearbox

Posted: Thu Dec 19, 2013 11:42 pm
by Doggy
davew wrote:anyone know if a 20MB02 6spd gearbox will fit a 406 110bhp there seems to be loads of them around fairly cheap.
As I said,

Be careful with 407 6-speed 'boxes. 407's have 17" wheels, hence lower gearing to compensate......

Also, jasper5 reckons the 16V 2.0 HDi in the 407 has a bigger DMF and clutch, hence a bigger bellhousing.

Re: 6-Speed Gearbox

Posted: Sat Dec 21, 2013 6:28 pm
by Bailes1992
munkymanmatt wrote:
Bailes1992 wrote:306 HDi gearbox would bring it down by about 500rpm and still has a cable clutch!
I assume this means it would be a much easier swap than having to put in a hydraulic clutch too?

but even then I'd still have to change flywheel and driveshaft right? Seems a lot of effort for 500rpm less!

You'd have to fit the clutch release fork from the 1.9TD onto the HDis gearbox.
Should be a straight swap then!

Re: 6-Speed Gearbox

Posted: Wed Jan 22, 2014 1:27 pm
by Rolebama
There is no guarantee of better fuel consumption with a higher gearing. It may work out that you need to use a little more throttle to pull it 'over-geared' which could bring your mpg down. I have had friends change their overall gearing just by fitting larger diameter tyres, and fallen foul of this.
FWIW, my Phase 1 306 TD sedan was 26mph per 1000rpm in 5th. Running on 185/65 x 14 I could get 65mpg at motorway speeds. Downside was that the tyres were of the 'semi-slick' type, and hopeless at emergency stops in the wet. (Fronts locked up too easily.)

Re: 6-Speed Gearbox

Posted: Sat Apr 12, 2014 5:41 pm
by steven123
Another happy 406 with 6 speeder, conversion done yesterday with new valeo smf and clutch, pedal is sooo light now dream to drive and cruise [emoji106]

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