timing cover bolts

[curt]

My 289 has( done by previous owner and just discovered ) three stripped bolts on the timing cover. The three lower ones. Cover seaps very little oil and when I put a wrench to the bolts they were finger tight. Problem was stripped threads, the bolts are fine. Can one tap these bolt-holes on the car? Will the metal scraps( from repair ) be in a position to just fall into the sump? Most likely harmless?

[N8N]

Unfortunately this seems to be fairly common; the aluminum "filler block" strips out very easily. IMHO the "right" way to do this would be to remove the oil pan and filler block and true up the front surface of the filler block (wet/dry sandpaper on a piece of flat glass, use light oil as cutting lube) then drill the four holes larger and insert Helicoils with Loctite. Then reinstall everything. May need to R&R the timing cover if the gasket sticks to the filler. A lot of work for a little repair.

You could try to do this on the car but am not sure how you'd keep the aluminum chips from settling in the oil pan. If you feel lucky dip your drill bit and helicoil tap in grease before each hole. Also a small hose on the end of your shop vac might suck up whatever does drop in there. Have heard of people doing this for spark plug holes in aluminum heads, so might be OK?

good luck,

nate

PS - this reminds me; I need to R&R both my timing cover and oil pan at some point in the vague future, so I might as well go ahead and prep a new filler block...

--
55 Commander Starlight
62 Daytona hardtop

http://home.comcast.net/~njnagel

[gordr]

IIRC, the holes in the filler block are blind holes; that is they do not go through into the oil pan. Easy enough to check with a suitable probe. Problem with tapping them out in place is that the tap may also cut the timing cover, too.

You know, what I'd try in this situation is to obtain some studs of the correct length, with coarse threads on end end and fine on the other. Carb mounting studs come to mind.

Use brake cleaner and Q-tips to wash ALL oil out of the threaded holes in the filler block, then set the studs into the holes with JB Weld. I'd coat the coarse-thread end of the stud with JB Weld, and also push a small blob of the stuff into the bottom of the hole. When the studs is pressed home, that blob will be forced into the annulus between the stud and the sides of the hole, and should form a good bond between the stud and the hole.

Leave it 24 hours to really set up; chip away any excess JB Weld that has oozed out, and apply fine thread nuts, and torque them up LIGHTLY.
Really, this will only cost you time and a handful of $$ for the materials, and if it doesn't work, you will be no worse off then before. It really wouldn't be "correct" for a concours car, although I expect few judges would be specifically looking for this modification.

Like N8 says, the time-honored correct way to fix this is to remove the pan and filler block, repair the filler block by Helicoil, and reinstall the new parts with new gaskets. OTOH, if it only seeps a little, you could elect to leave it, and allow your car to mark its territory This is one little leak that is unlikely to become a flood.

Gord Richmond, within Weasel range of the Alberta Badlands

[N8N]

Thanks Gord, I don't know why I didn't think of that. I may just Loctite some studs into mine if I don't happen to have the right Helicoils on hand. In fact, if they are blind holes, I may do that anyway, as the Helicoil taps are probably like normal taps and have a significant "taper" on the end and I'd have to either drill all the way through and then plug the holes, or else buy another Helicoil tap and mod it into a "bottoming" tap.

JB-weld on stripped holes will probably work, too, ASSuming that the holes are cleaned out well. I'd probably use carb cleaner followed by aerosol window cleaner (the latter is my favorite wipe-down before paint for old parts, as well.)

nate

--
55 Commander Starlight
62 Daytona hardtop

http://home.comcast.net/~njnagel