Changing Final Drive in a F10 Gearbox

[krobinson]

I have a 4:18 crown wheel and pinion to go into my F10. Took the bottom "sump" plate off, now i'm completely lost. There's nothing in the haynes manual about how to change it.

Anyone give me some pointers?

Keith

[Stuart]

hee hee get ready.



get the car on axle stands, both front wheels off the floor. (remove passenger wheel)

undo either the bottom ball joint (13mm) bolt or take lower arma and tie bar off, so you can pop out the CV's from the gear box.

undo the lock tag (10mm) from the passenger side of the diff housing (on the big ass castle nut). then get a sturdy piece of angle iron and start to undo the diff nut. once thats undone you can jiggle the diff out. replace the gear on that with your 71 toothed 4.18 one, use thread lock on the CW bolts. (refit is reverse of removal, but dont fit it yet)


next, get a lack under the gearbox and undo the front lower engine mount and undo the earth strap, then lower the box down till you have access to the gearbox end plate. undo all the long bolts (14/15mm) (there are 4 short ones which you dont have to remove, unless you want to redo the seal).

take the selector off the top of the gear box (10 or 11mm) lift it out.

you should be able to split the gear casette out and pull it from the box.


the small FD gear (17 teeth for the 4.18) is the last gear on the shorter of the two shafts. get some circlip pliers and remove the circlip (its a tricky customer) sometimes the gear lifts off, other times it needs a tap (ie hold the gear and hit the shaft with a copper hammer), in extreme cases you need a hefty puller to get it off.

refit is reverse of removal (note the direction of the helical cut of the gear)


clean up the magnet and also the spacer wahser. dab grease on the washer and then place it back on the D shaped shaft it came off. aldo apply silicone sealer to the magnet and push it into its house.


put silicone on the casette faces and slide the casette back in. refit diff and selector top hat. and sump

DONE

[Jim]

Or do what I did and get Cambridge to fit it :D

Jim

[Stuart]

fund e a trip to NI and i will lmao

[brian]

I clicked on to this preparing to type a big long explaination but thankfully cambridge got there first!! :wink:
I think it was you cambridge that went through that with me before too.
Anywho, have Fun Keith, its not a bad job to do anyway.

[Stuart]

i think ive had gearboxes appart enough now to do it with my eyes shut lol