VW T4 5th gear upgrade– T4mation.me

Brand new 5th gear pair for Volkswagen T4 transporter 5 speed gearboxes.

The 27 teeth / 41 teeth, uprated 0.658 ratio provides better fuel economy.

Included is a replacement thrust washer for the driven gear that you will need.

1 x 5th gear 41 teeth (OE reference - 02Z 311 158A)

1 x 5th gear 27 teeth (OE reference - 02Z 311 361A)

1 x Thrust washer (Genuine OE 02Z 311 324)

The gears in this kit have been produced by an OEM manufacturer, ensuring that the quality and performance are of the highest standard for your transmission repair.

The gear sets fit both diesel and petrol models. This is a guide to let you know what changes to expect. Please note this an average guide across the rage as there is many different gearbox’s and rations.

1.9D and 1.9TD in our opinion it’s best to get 0.658. This will save you 500 revs.

The only exception here is if you tweak the turbo and fuel to get power gains up to 90bhp and with this you can go for the 0.622 ratio.
Example

At 70mph you would expect to achieve 3000revs with the 0.658 upgrade. (Current revs @70mph 3500)

At 70mph you would expect 2500revs with the 0.622 upgrade.

2.4D and 2.5tdi in our opinion it’s best to get 0.622

Example

At 70mph you would expect to achieve 2500revs with the 0.622 upgrade. (Current revs @70mph 3000)

This upgrade is also good for all petrol engines. The drop in revs is different for each engine modal but a good average is 500 less revs at 70mph than you currently have.

With all products you want peace of mind and to know it's worth the price tag! All products listed we have and still do install on our conversions fitting service available. They have been tested in the real world and got our seal of approval. Any questions send a message and we can answer any questions and talk you through the options. We are not just here to sell things we install too!

FAQ:

Will this fit my ACV 75 KW engine?

Yes, a 5th gear upgrade can usually be fitted to the ACV 75 kW engine (which is a T4 2.5 TDI engine), but it depends more on the gearbox type than the engine itself. The ACV engine typically uses the 02G gearbox, and many 5th gear upgrade kits (to increase cruising speed or lower RPMs at motorway speeds) are made to suit this gearbox.

✅ If your gearbox is indeed the 02G, there are aftermarket taller 5th gear kits available that will fit.

Will this fit my 1.9 Engine/Gearbox?

✅ Yes all 1.9 Engines will fit this model of 5th gear for your van, they're all compatible with the 1.9's gearbox.

Will this fit my 2.5 Engine/Gearbox?

It all depends on the gearbox you have, with the 2.5's there's 2 variations of gearbox you can usually have.

✅ 02B Gearbox – this 5th gear will fit your vehicle, as your reverse gear is located to the left of 1st gear, which means it's compatible with the 5th gear mod.
The 02B gearbox is well-suited for this upgrade, allowing you to fit a taller 5th gear ratio to reduce cruising RPMs, improve fuel economy, and make motorway driving quieter and more efficient. It's a popular and proven mod for many T4 owners looking to enhance long-distance drivability.

❌ 02G Gearbox – this 5th gear will not fit your vehicle due to reverse gear being located below 5th. A 5th gear mod typically won’t work on the 02G gearbox found in 2.5 TDI T4s because the gearbox design is different from others like the 02B, it often already has a tall 5th gear, there’s limited aftermarket support, and fitting a taller gear can cause drivability issues, clearance problems, or make the engine struggle at low RPMs..