Any owner of a 207 THP will tell you that the 5speed gearbox needs a longer 5th gear. The 5th gear ratios on both 207 THP150 and THP175 are very short and not useful for good fuel efficiency.
Peugeot and Citroen fixed that problemyears later, by switching over to a 6-speed gearbox in facelift THP156 models, where 5th and 6th gears are overdrive. For everybody else, who has the models that were produced up to 2010 or a GTi/RC, the only reasonable solution is to upgrade the 5th gear set in the stock gearbox.
The good news is, it is an easy process. You do not have to remove your gearbox in order to do this. But you have to be careful because the gearbox will be opened from its service hatch, on the front left wheel side. It is strongly recommended that you renew your gearbox oil after this upgrade.
Options available for the upgrade
There are two gear sets available from Peugeot/Citroen, that can replace the stock one (BE type gearboxes have been manufactured for many many years and there are parts for them in every corner of this planet):
- 44-35 – PSA part code 2344.E2 (about 10% longer than stock)
- 47-35 – PSA part code 2344.F2 (about 15% longer than stock)
- 50-33 – PSA part code 2344.F5 (longest of the lot, comes from HDI gearboxes)
Supplemental PSA codes you might need to replace the gear set. It is a good idea to have them, you have to be really careful not to damage the safety nuts and clips while removing:
- 2304.81 nut and clip
- 2304.59 nut and clip
- 2339.33 internal bush
As the numbers imply, 50-33 is the longest while 44-35 is longer than stock but somehow intermediate. The 50-33 set is the longest of the lot by far and only recommended for highway travelling. We recommend 44-35 for THP150 (Peugeot 207 GT/Rallye/XS THP150) and then 47-35 or 50-33 for THP175 (Peugeot 207 RC/GTi THP175). This is because the THP175 has a shorter final drive ratio and all gears are shorter than the equivalent of THP150. THP150 has a longer final drive ratio, which makes all of its gears longer than THP175.
Of course you can use a 47-35 or 50-33 gear set on a THP150 if you want to have super low fuel consumption on the highway, at the cost of low rpm driveability and responsiveness.
In the following photos you can see how we did it on a 207:
Make sure you remove both gears, so the new set can be installed. Removing only one will not work, these work as a pair.
Remember: 2344.F2 is the 47-35 gear set (the longest of the lot) that fits really well to THP175 – Peugeot 207 RC/GTi.
This is it! Be advised, if your car is equipped with a Cruise control function, it will stop working. Because the new gear set needs to be calibrated into the Engine computer. The computer estimates the gear engages via rpm/speed correlation. It does not know the correct new gear ratio and it loses this, so the cruise control system stops working.
We correct this by remapping the car and calibrating the 5th gear ratio. Once it works, you can fully enjoy the lower fuel consumption and much more quiet operation during cruising with the new gear set. The difference makes this modification really worth it. It is typical to see consumption improvement of up to 1lt/100km, as the engine rpm is much lower (more than 600rpm) at 120-130km/h on the highway.