Here's a little project that has been on the to-do list for a
while but I kept putting it off - protecting the oil pan. I guess I had just
been lucky the past 9 years and never got a rock in close to my oil pan.
My luck ran out a few weeks ago when I rolled a medium sized rock just right
with my front axle tube, causing it to swipe the oil pan creating a slit about a
half inch long.
The trail fix was pretty easy. First we drained the oil into some water
bottles, then cleaned up the exterior of the pan. I then forced some
silicone into the slit and let it setup for about a half hour. Next I took
a piece of cardboard and smeared a thick layer of "Right Stuff" rtv on it, then
I attached the sticky side of the cardboard to the bottom of the oil pan
securing it with a few strips of duct tape. This fix has been leak free for the
past two months but it was time for a permanent fix.
I could either make a large skid plate or add some armor to the oil pan. I
chose to add some armor to the oil pan since it is tucked up into the chassis
pretty far and rock contact is pretty rare (once in 9 years). As luck
would have it I had an oil pan from what was supposed to be another Series II
3.8l motor and since the blocks are supposed to be interchangeable I decided to
use it. I plasma cut a steel plate roughly .100 thick and tried to match
the odd shape of the bottom of the pan as best I could. Then I used a
hammer to form the plate to better match the contour of the oil pan. This
was a bit harder than I expected and I had to make strategic cuts in the plate
to get some sections to conform to the pan better. I then welded the
plate in even increments, managing to blow thru the pan only once. Before
final assembly I smeared 'Right Stuff" rtv onto the inside of the pan over all
the welds mainly because the welds looked contaminated and porus.
Next came the time to pull the existing oil pan and upon doing so I discovered
the two pans were different [insert bad language here]. The "new" pan was
from a normally aspirated 3.8l and the apparent differences were: the 3 mounting
holes near the end were slightly off from the existing pan, it featured an
integrated oil splash guard and the mounting flange was not smooth (next to each
hole was a pair of raised bumps which looked like spot welds but were not).
I am guessing the bumps were supposed to dig into the gasket. The problem
was the S/C pan had a plastic spacer/gasket/splash guard that went between the
pan and block.
I set about cutting out the existing oil splash guard from the new pan, ground
down all the bumps next to the mounting holes and then tried elongating the 3
offset holes to "move" them to the proper location. I ended up throwing
the pan on the mill at work to open up the holes since they were roughly a half
a hole off and I broke my dremel bit trying to elongate them at home.
One other thing I checked was to see if I could drop the oil pickup down to
submerge it into the oil more. As it turns out the pickup is already very
close to the bottom of the pan although it is angled slightly front to back.
it looked like you could drop it maybe a quarter inch but I decided not to mess
with it. I used some silicone to reseal the pan due to the gasket being exposed
where the three elongated holes on the backside of the pan.