Driveshaft output oil seals

[M100TURBOFR]

Driveshaft extractor.jpg

Hi Preparing to replace leaking output oil seals. Is it a "gearbox down/out" job or can it be done in situ? Are they easy enough to prise out? Re driveshafts, do I require an extractor (see attached photo). Have not yet read appropriate manual section. Thanks in advance for any advice.
David

[dapinky]

Hi David,

I have replaced many seals over the past 15 years - all because the first time I swapped out an engine/box I didn't bother, and it leaked almost as soon as I filled it with oil afterwards..... now I do them every time I disturb a driveshaft with an unknown seal (ie, anything that wasn't fitted in the past few months).

It is far easier with the gearbox out of the car, but it can be done with it in.

Getting the old ones out is just a pry-bar or screwdriver to carefully lever it out using the inner edge and accepting that it will destroy the seal (not a problem!).

To fit the new ones, I line them up by hand, and tap the edges with a light hammer to set it in place, and then use a wooden bar to drift it home fully. It is hard to get a hammer/mallet on the seal directly and still get enough swing on it to get it in, so a piece of 2" x 2" wood works well enough to hit with a hammer.

Have you already bought your seals? if not, I can recommend rockauto - I bought 4 x SKF13750 seals from them earlier this year for about £5.50 each inc VAT. Of course, if you are only getting the seals, then postage will have an effect - they are a part used in other cars, so should be easy enough to source locally (even in France!).

Obviously, you will lose some gear oil when you remove the shafts, so i would recommend draining the box first (drain plug on LH side)..... and when you refill it, you can use the 'D' shaped plug above the drain plug (with a suitable bit of work to undo it!) and just pour in 1.8L of oil. The hole is a 'fill' hole, not a 'level' hole, so don't expect oil to drip out when it's full - it actually takes an extra 0.65 L to get the oil to drip from that hole.... I did the experiments about a month or so ago.

This way you don't need to disturb the speedo drive to fill and check the oil level.

As for removal of the shafts, the right side one will simply pull out of the gearbox if you undo the central bearing on the jackshaft (where it bolts to the engine block) and withdraw the whole lot..... the snap ring is on the joint between the inner and the outer shaft. If you find it easier (I do!) to split the shaft, then it will separate with a sharp jarring motion using a couple of pry bars to lever the 2 halves apart - the same to get the left-side shaft out of the gearbox. The tool you picture may or may not help, as the access is awkward anyway so it may not go in easily.....

.... it's one of those jobs that sometimes works first go, and sometimes takes a few different attempts with slightly different positions.

[M100TURBOFR]

Dave Thanks. Excellent advice as usual.
David