[haasad]

Hi, I just did this to my 7R cases. It really wasn't a problem . First it is essential to remove the internals of the little squirters to do this I drilled by hand at 6.0 mm diameter directly into the accessible side of the squirter to a depth of 3 mm . This removes the rolled lip that holds a small alloy disc with the squirt hole in place. Behind this disc is a spring which bears on the steel ball which acts like a little valve allowing the oil to pass up through the squirter. Now you need to hook out the disc , the spring and the ball. If the ball is stuck it can be blown out with an airline from the oil gallery. You are now left with an aluminium cylinder with the ball seat at its bottom stuck in the case web.

I waited for the new squirters to arrive so I knew the outside diameter and depth to drill to. I think mine were 6.2 mm diameter and 25 mm deep but am not sure . The new ones give an easy guide.

I did not heat the case web but simply drilled very carefully right down through the old part at 6 mm diameter. The alloy is soft and the mag 7 r case relatively harder to cut so the drill almost self guides and its very obvious when you are right through.

I then opened the hole up to size with a 6.1 mm drill ( they always cut oversize) to leave a new bore for reaming at 6.2 mm diameter( using a backed off drill ) ready to accept the new squirters.

The new squirters were a nice slide fit into the case after this work so I cleaned it all perfectly with brake cleaner and fitted the new parts with the minimum of Loctite engineering adhesive required to ensure a good bond and seal. I then "staked" the top of the new bore with a square tipped punch.

I proved each new one with the usual methods.

I did this at home with basic tools just a Makita battery drill and and good quality drill bits...however I am a time served mechanical engineer with 30 years plus experience of metal and machining. I'm not sure alloy cases would be so "friendly" to work since it may be harder to follow the alloy squirter body with the drill. I would consider making a simple jig if it was a problem but getting the right angles could be troublesome.

For the record I tried drilling and tapping then slide hammer ( I even made a mini slide hammer ) but had no luck.

Hope this practical experience is some use..and offer a warning that new cases are expensive but temper that with the fact that if they are alloy a repair to an over drilled hole may not be so much ...your choice.

regards.

andy