Hi everyone, there have been a few questions around the overdrive fitment I did to my Mk5.
My priority was to keep the car as standard as possible, and the only issue I was concerned about was cruising speed, and the limitations of the low-revving pushrod engine combined with 4 speed gearbox.
Fitting an overdrive means you can retain your original car gearbox, I was not prepared to start fitting a different gearbox from other cars. You need a donor moss box with overdrive. Our mk5 gearbox was in excellent condition, with no gear or synchro wear apparent. Therefore, we stripped the donor mk7M/mk8 gearbox, so we could use the longer main shaft. We stripped the mk5 gearbox, and re-assembled using the longer main shaft, and then the overdrive just bolts onto the rear.
I will try and take some pics this weekend, as ironically we have had some oil pressure issues with the overdrive, I have done 1,000 miles of running in, so am now doing the first major service. The oil pressure issue has been identified as the O ring seals we fitted to the accumulator piston - within 1,000 miles the new seals have shrunk! Cheap chinese rubbish from a reputable bearing supplier. We managed to locate some high temperature O rings, not easy as its a size that is not commonly utilised in any other applications.