MatraSport Forum

In checking over the gearbox and bell housing, which is out of the car and on the bench, I noticed that inside the differential, where the left side drive shaft is inserted, there is a loose 2cm disc. I suspect this is what stops oil leaking out past the drive shaft splines and it probably fell out because I gave it a tap when trying to extract the right hand drive shaft. Oops!

I've removed the differential casing and lifted out the main gears in one piece, but I still can't get access to this disc. Can anyone suggest the next step please? I guess it's some kind of push fit, but I need to get to the inside surface of it to get it back. The options seem to be to remove the bearing from the spline tube, or remove the 12 bolts on the diff to dismantle it further. I don't want to go any further until I've checked with you guys further.

I managed it! I had to undo the 12 bolts on the main gear in the diff, remove the bearing from one side then slide the planet gears out of the way then I could access where the disc came from and tap it back in. Everything else looked good inside there with no chunks of metal, just a small amount of swarf on the magnetic drain plug. I hope the gearbox is as good because I’ve never been able to use it yet, so an oil change is all that it’ll get with a couple of new linkages and top hat bush.

Good job done.
Just saw your second post as i was replying as i had to do this on my car.
Although you have tapped it back in i would suggest putting the shaft in a vertical position with some oil in to check if it has re-seald properly as it has been disturbed and as you will have seen it is an inteference fit.
If it leaks and you need to replace it, it is 30mm in diameter.
Peugeot Citroen part number 3111.11 is the one I used to replace mine.
I had advice and help from Roy Gillard to remove my engine and I could not get my short drive shaft out. I had to take the shaft and the diff off together and separate on the bench. I had to unbolt and dismantle the diff to get at the core plug and it was removed by forcing a screwdriver into it to distort and then prise it out.
I stripped the diff down to clean and check whilst it was apart.

Regards
Ian

Thanks Ian. The disc was in good condition and a very tight fit when I tapped it back in, so hopefully it'll stay there. I'll try your leak check idea, maybe a bit of thinner oil would be closer to warm transmission oil for cold leak checking?

I count myself lucky that the drive shafts came out OK. My biggest problem was hub nuts, but I won in the end!

This core plug is fitted as you guessed to prevent the oil escaping, or having to drain the gearbox if you want to remove a drive shaft.  When you tap it back in, even if it seems a tight fit, you should hit it hard in the centre with the ball end of a ball pein hammer.  This flattens the curved core plug and makes it lock into the hole so it should not come out again.  You don't want this dropping out inside the diff. whilst driving the car!

I have new core plugs in my stock if anyone needs one.

A small amount of swarf on the magnetic drain plug is normal, as long as there are no large pieces in it!

Roy