03-12-2020, 09:44 AM
It is a fairly easy, satisfying job.
You drill out the old threads, using the drill bit provided. Don't forget to put it back in the box with the coils, it is an odd size.
Tap out the hole with the tap provided, you really should invest in a proper holder for the tap.
When tapping it is good practice to take a (say) half turn, then turn the tap back a little to cut the swarf so it doesn't build up and mess up the thread you are cutting.
Maybe remove the tap after a couple of turns and blow out the bits if you can, then carry on.
Screw the helicoil in until it is just below the surface of the casting, using the tool provided. Then if you turn the tool backwards, the tang at the bottom breaks off, you turn the job upside
down to get the little wiry bit out, and the job is done.
What can go wrong?
You can drill too deep, you can tap too deep. Doesn't matter with through holes, but can do do damage if in a blind hole. The sump has both.
You can drill at an angle. Not usually a problem, the thing is usually self guided by the old hole, and not particularly a problem with sump bolts. Not
so good where I have just managed to do it, though.
You can drill/tap too shallow. You discover this when the Helicoil sticks out of the hole. The coil will NOT wind out, don't try unless an important bolt.
The projecting coil can be cut off flush or nearly so with a sharp pair of side cutters and dressed back to the surface with a careful file. If you have really cocked it up,
you may need to shorten the bolt. Those that know these things say you only need a couple of turns on a bolt to get the design strength of the joint.
The tang at the bottom of the coil doesn't break off - this happens with my current batch of coils. A problem if the bit breaks off later and goes round in the engine with the oil flow.
No easy answer with that one, you have to fiddle a way to extract it if need be.
If you can, do a practice hole in a spare bit of aluminium before starting on the car.
Hope this helps, you did say you hadn't done it before.
You drill out the old threads, using the drill bit provided. Don't forget to put it back in the box with the coils, it is an odd size.
Tap out the hole with the tap provided, you really should invest in a proper holder for the tap.
When tapping it is good practice to take a (say) half turn, then turn the tap back a little to cut the swarf so it doesn't build up and mess up the thread you are cutting.
Maybe remove the tap after a couple of turns and blow out the bits if you can, then carry on.
Screw the helicoil in until it is just below the surface of the casting, using the tool provided. Then if you turn the tool backwards, the tang at the bottom breaks off, you turn the job upside
down to get the little wiry bit out, and the job is done.
What can go wrong?
You can drill too deep, you can tap too deep. Doesn't matter with through holes, but can do do damage if in a blind hole. The sump has both.
You can drill at an angle. Not usually a problem, the thing is usually self guided by the old hole, and not particularly a problem with sump bolts. Not
so good where I have just managed to do it, though.
You can drill/tap too shallow. You discover this when the Helicoil sticks out of the hole. The coil will NOT wind out, don't try unless an important bolt.
The projecting coil can be cut off flush or nearly so with a sharp pair of side cutters and dressed back to the surface with a careful file. If you have really cocked it up,
you may need to shorten the bolt. Those that know these things say you only need a couple of turns on a bolt to get the design strength of the joint.
The tang at the bottom of the coil doesn't break off - this happens with my current batch of coils. A problem if the bit breaks off later and goes round in the engine with the oil flow.
No easy answer with that one, you have to fiddle a way to extract it if need be.
If you can, do a practice hole in a spare bit of aluminium before starting on the car.
Hope this helps, you did say you hadn't done it before.