Hi,i was wondering if anyone has done a conversion from 5 to 6 speed on a skoda octavia 3 1.6 tdi, 81kw, engine cxxb? Or if anyone knows which gearbox will be plug and play? Same axles, same clutch,same starter motor? And will i be able to code the gearbox with vcds or obdeleven? Thanks in advance,cheers.

Easiest thing is if you find a scrapped late 2017 TDI1.6. These all came with 6 speed gearboxes as standard.

Hi,i have all the necessary bits to make the retrofit,it's only the software part that's bugging me.

Any reason you’re not just buying a car with a six speed box in the first place?

15 minutes ago, SC03OTT said:

Any reason you’re not just buying a car with a six speed box in the first place?

Yes,the car was very cheap, but already had a 5 speed,for 200 euros i got everything needed to make the conversion.i bought the car for 5000 €, plus 200€ of the gearbox, 5.200 €. I'm not quite sure where you will find a 6 speed skoda octavia 3 from 2015 with 115.000 km for 5200.thats basically the reason.

Hi everyone!

I’m also interested in converting my Octavia III 1.6 TDI from a 5-speed to a 6-speed manual gearbox.

Mine is a 2013 1.6 TDI CLHA, originally 105 hp. It has been remapped with an additional 50 hp (around 155 hp in total), and the DPF has also been removed.

I bought it in 2021 for €2,900 with 170,000 km on the clock. It now has around 250,000 km.

Recently, I’ve been having problems with the gearbox, especially when downshifting. Fourth, third and second gears are all becoming very difficult to engage. As far as I can tell, the clutch isn’t slipping and doesn’t seem to be in particularly bad condition.

If the gearbox itself turns out to be the problem, I’d rather replace it with a compatible 6-speed gearbox instead of fitting another 5-speed one.

My main goal would be to reduce engine RPM at motorway speeds, improve fuel economy and make better use of the extra power.

Does anyone know which 6-speed gearbox would be the most compatible with my CLHA engine?

I’d also like to know:

• Would I need anything else apart from the gearbox and gear selector/linkage?

• Can I keep my original driveshafts, gearbox mounts, clutch and flywheel?

• Would any ECU coding or other software changes be necessary?

• Has anyone actually completed this conversion on a front-wheel-drive 1.6 TDI?

I’d really appreciate any advice, especially from anyone who has already done this conversion.

Thanks in advance!

I did 5 to 6 speed gearbox swap for my 2002 Mk1 Octavia TDI after a couple years ownership from new. Aside from the gearbox including gear selector on top, reverse switch and speed sensor, you will need matching gearbox mount and its console, dogbone mount, driveshafts, flywheel and clutch including slave cylinder and related piping, and a whole lot of new bolts as a lot are stretch bolts. Ironically, the gear lever and linkage fitted both old 5-spd and new 6-spd, so I did not bother replacing the gearstick nor linkage and had a "secret" 6th gear for the life of the car, ie still 5 gears+ reverse printed on the gearstick yet the 6th could be selected. Aside from this, the airco piping is usually different between 5 and 6 speed gearboxes, but I was able to get round this by fabricating an additional mount (just a small piece of steel bar with a couple holes). Speed sensor needed adaptation somewhere using VCDS, but the difference was not massive.

In summary, it was quite a bit of hassle getting all the parts and then a half day of work.

For me, the reduced revs on motorway were worth it though, both for comfort and for fuel bill. At least at autobahn speeds of 100mph+ I estimated that the saved fuel has more than paid for the outlay on gearbox swap over the 80k or so autobahn miles. Note at UK motorway speeds the fuel saving would likely be minimal, and at current diesel prices at least it makes financial sense to go slow anyway.

Also note that this was 22 years ago, and since then Adblue injection and engine cooling layout changes went in, so there may be other parts that interfere and may need replacement. HTH

Edited 49 minutes ago49 min by dieselV6