Hi just a quick question. I replaced my gearbox driveshaft on my fiesta mk7  1.4tdci 2008 but I think I pushed it in too far, is it possible to do this? It started to leak again. So I’ve took it out and I’m going to put another one in tomorrow. Do I keep it flush with the gearbox housing or tap it in as far as it goes?

It shouldn't be possible to push it in too far.  Perhaps the new shaft was slightly different with the splines being a bit shorter?  Or perhaps the oil seal was damaged during the shaft change. 

I did a couple of clutches where the oil seals looked ok but then leaked after refitting.  Much easier to replace the seals while the gearbox is out of the car so I started replacing them as a matter of course with every clutch I did after that.

I’ve just finished it and used a tool to help tap it in( not got a clue what it’s called). Gone in much better. Filled the gearbox with oil and an hour later it’s got a drip underneath and yet I wiped under there completely dry. Going to take it for a ride and then see. I’m not replacing it for the third time. Do you think the gearbox sealing stuff you can get will help.?

6 minutes ago, Suejr said:

Do you think the gearbox sealing stuff you can get will help.?

No.  Sounds like it needs a new oil seal.

Genuine Ford Manual Transmission Diff Oil Seal 1805715 | eBay