Originally posted by Holmenkollen
OK, here goes.....
No guarantees. Just because I appear to have got away with it, doesn't mean anyone else will
Tools and parts needed:
Mains electric drill with a 1/2" chuck and variable speed
6.0mm drill bit
2.5mm drill bit
A medium grade file (or one on a Swiss Tool or somesuch)
A junior hacksaw with a blade in new condition, or just a new blade and a steady hand
2x TA-04 Delrin diff joint kits (only need the long, non-bearing end)
Method (adapt to suit if you want)
1) Seperate out the long ends of the diff joints and the stabilising rings (glorified washers). You cannot use the short ends as they house one of the diff bearings and there is not enough meat left on them when they are drilled out.
2) Using the 6.0mm drill bit and the battery drill/driver, drill out both long diff ends to 6.0mm, from the rear (flared) end.
3) Slip one dff joint over the shank of the 6.0mm drill bit and clamp it in the chuck of the mains drill. Set the drill to a medium-low speed (600-1000 rpm).
4) lock the drill 'on' and steady it with your left hand on a flat surface.
5) Using the file, gently move back and forth on the exposed flared end of the diff joint until it is level (or nearly so) with the body of the joint.
6) Using the saw (or blade), cut 3mm off the end of the joint.
7) Stop the drill, take out the drill bit and joint and turn the joint round on the drill bit. Reclamp the joint in the chuck, but this time with the slot end outward.
8) Slip a stabilising ring onto the slotted end of the joint until it hits the stop.
9) Using the saw (or blade), cut off the end of the slotted portion 2mm away from the stabilising ring.
10) Remove the diff joint from the drill and slip it off the 6mm drill bit.
11) Using an old diff cup as a guide for height, drill a 2.5mm hole through the bottom of the joint body exactly in line with the slots.
12) Repeat steps 2-11 for the other joint.
13) Remove the top deck, top-bottom deck ties (if fitted, or the inner battery cradle if not), front top diff cover (if fitted and IMHO it ought to be), and pop off the steering link.
14) Pull out the front driveshaft/pinion assembly and the propshaft with it.
15) Remove the rear diff cup and replace it with one you have just made. Repeat on the removed front shaft
16) Slip both stabilising rings onto the propshaft and locate the shaft in the front cup/shaft assembly.
17) Locate the propshaft in the rear cup and push the front driveshaft/pinion assembly back into the front diff. If it will not go in, you did not cut enough off the back of the joints in step 6. There should be approximately 1mm play front to back on the propshaft.
18) If all is well, slip the stabilising rings onto each joint (or now, drivecup) and superglue into position.
19) Replace the diff cover, ties, steering link and top deck.
19) Test run, sit back and admire handiwork.
If you find at point 17 you have a problem, you have two ways round it.
You can carefully file the slot on both cups a little deeper, or you can remove them, cut a bit more off the back and then re-drill the 2.5mm holes at 90 degrees to the original ones.
You will probably get a little vibration on the propshaft, but it should be so small as not to worry about. I reckon it's about right for non-precision engineering?
This doesn't take half as long as it looks, I had the car working again in an hour and a half.