Helicoil install for oil pan Assembly

[OldBlue2002]

So, several years ago I took on the task of changing the oil pan gasket (also did motor mounts the same day). I used the cork gasket (gasp!) and black sealant (silicone I think). Everything went fairly smoothly until I went to bolt up the pan and two bolts sheared off (one in the front and one in the back). Each bolt was installed using a torque wrench, so I’m not sure if those two bolts had weakened or what happened.

This past weekend, I went to try removing them and was able to get the front one out easy peasy. However during the aft bolt removal, the tip of the ez removal tool broke off inside the hole. After a few hours of trying to get back where I started, and I’m left with a pretty boogered up hole that appears to be past the point of recovery with the original threads.

i have an M6 helicoil (E-Z Lok) coming in the mail, and without intervention, I plan on pulling the pan down again, drilling and tapping a 3/8 hole to install the 3/8 OD M6 ID helicoil. I will also use the “aftermarket” Victor Reinz pan gasket from Blunt, because it looks like the cork/silicone method didn’t stand a chance. I’ll probably try tacking this on Saturday, so if anyone has any experience with doing this or sees any red flags in my plan, feel free to steer me back on course.

 

Scott

Edited June 8, 2020 by OldBlue2002
Photo added

[jimk]

The one in the rear is into the aluminum rear seal case.  the case is bolted to the block around the flywheel.  There may not be much meat to be drilling into in that aluminum piece.  Can't give any advice other that to use caution.

On 6mm bolts, it defies my best judgment to use a torque wrench.  Tightening by feel avoids over torquing with a wrench that is meant for much greater torque values.  Go back after a few heat cycles and snug each bolt as necessary.

[Son of Marty]

As Jim said theres not a whole lot of meat there so go slow, but if it doesn't work you should be able to source a used one on the board the bad news is you'd have to remove the trany and flywheel. Torque wrenches are only truly accurate in the middle half of their scale so a 200 ft/lb wrench should be used to torque 50-150 ft.lb. I believe the pan bolts are torqued to 8 ft/lb so you should use a inch/pound wrench at 96 in/lb. You should dimple the pan before you reinstall it by taking a small ball peen hammer ball side into the bolt hole and taping it lightly with another hammer to lightly dent the hole outward a bit this will let the pan sit flat on the gasket.

[OldBlue2002]

20 minutes ago, Son of Marty said:

As Jim said theres not a whole lot of meat there so go slow, but if it doesn't work you should be able to source a used one on the board the bad news is you'd have to remove the trany and flywheel. Torque wrenches are only truly accurate in the middle half of their scale so a 200 ft/lb wrench should be used to torque 50-150 ft.lb. I believe the pan bolts are torqued to 8 ft/lb so you should use a inch/pound wrench at 96 in/lb. You should dimple the pan before you reinstall it by taking a small ball peen hammer ball side into the bolt hole and taping it lightly with another hammer to lightly dent the hole outward a bit this will let the pan sit flat on the gasket.

You and Jim are spot on. That bolt goes right into the rear cover, not the block like I had guessed. I happen to have a rear engine seal in my toolbox waiting for the next time I had the transmission/flywheel removed. 
The EZ Lok is 10.3 mm deep and I can’t tell from pictures of the cover whether there is enough material to accommodate installing it. I’ll be careful, but at least it’s a replaceable component I’ll be drilling rather than the block itself. Thanks for the replies.

[OldBlue2002]

Also, I’ll never be using anything but a 1/4 inch drive socket (or wrenches) on any bolts/nuts smaller than 13mm ever again!

[Son of Marty]

Yeah I love my 1/4" drive set.