6-Speed Gearbox

[Busman]

This is very interesting. Any idea of a time scale for doing it? I guess that the getting the engine in and out is not to be under estimated?

[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?

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

I was trying to work that one out from the diagrams, so it actually comes out still wrapped around the driveshaft? That's going to make things a bit easier...

I also noticed that the main case and diff carrier are the same part numbers, seems maybe even too easy...

[Doggy]

This is very interesting. Any idea of a time scale for doing it?

Not yet.

I guess that the getting the engine in and out is not to be under estimated?

I was thinking to leave the engine in situ & drop the 'box, as you would for a clutch swap.

[FarmerPug]

I read the tread on the coupe club aswell, do you think the 6 speed box would work in the 2.0 HDi?

[Doggy]

I think so, but probably not the same version, as the flywheel and clutch are different.

I have no idea how you would prove this, other than by trying, but I think the more common 20MB02 'box from a 2.0 HDi 407 might well fit. It won't have the speed sensor, but it should have a removable cover, into which yours will fit.

Be careful, this is just theory, based on what infomation I stumbled on researching the 20MB04

[FarmerPug]

Had a quick look there for 20MB02, its a lot easier to find than the 20MB04

Looking at the pictures there does seem to be the blanking plate for the speed sensor near the driveshaft hole,

Its very clear here:
http://www.ebay.co.uk/itm/Peugeot-Citro ... 4cfeaddb9b


What are you planning to do about gear linkages.

[grasmere59]

I was also wondering what happens to the gear linkage to get the 6th position.

[Welly]

I was also wondering what happens to the gear linkage to get the 6th position.

Something like this maybe:

[benczuk]

thanks for the best laugh in days!

[lozz]

[FarmerPug]

[steve_earwig]

Blimey, you'd need to be an octopus to drive that

[Doggy]

YES! The news the nation's been waiting for........

No, not another royal to pay for, Doggy's 6-speed 'box is in and running.

Another top job by our resident maestro jasper & co.

Old 'box out,
New DMF + clutch in
Both diff housings stipped down
Speed sensor drive gear swapped over
New 'box in
Plus a drop link changed as well
.....all in under 6 hours.

This here's the 6-speed still with the C5 mounting bracket etc attached - you can see the little blanking cover over the speed sensor hole in the diff casing.


And this view shows the little plastic gear that drives it, clipped onto the outside of the hollow output shaft the driveshaft plugs into. (It's not on the driveshaft as I had previously thought). This is a minor complication, but means you need to split the diff casing to remove it from your ML5 'box, then do the same to cip it onto the ML6.
Fortunately, we quizzed Joost from the coupe forum at Pugfest last week, so were better prepared for this.


The ML6 is fractionally longer, (only about 10 mm), doesn't cause any issues.

Other than that, it's pretty much a direct swap. The C5 mounting bracket uses 3 of the 4 mounting points on the top if the gear casing, the 406 bracket uses 2 of the same holes, but also uses the one previously unused on the Citroen. As this thread has never been used but has had 10 years to corrode and fill up with muck, it's a good idea the make sure the bolt fits before you install the 'box, (as we found out the hard way).

The two gear cables clip onto the selector levers easily enough, the 3rd (reverse inhibit), cable is also a direct swap.

In summary, the only tricky operation is swapping the speed sensor drive gear, it's essential to re-seal the joint faces and replace the diff oil seals when doing this. Other than that, it's virtually the same job as changing a clutch.

[nutski]

Excellent news!
All driving well i presume?

[lozz]

well done.
I wonder how long itl be before your cruising on the motorway n your looking for
A 7th gear..