Change your leaky rear main seal
At about 2400 miles on the odometer, my rear main started leaking like crazy. After a 10 mile drive the entire bottom of the tranny would be soaked, and worse yet, the floorpan, necessitating a lot of simple green and elbow grease to clean it up. So, I decided to tackle the job after talking with John Pearcy of John's performance to get some pointers. I apologize for the lack of pictures but my hands were really, really oily most of the time and I didn't want to get my camera filthy.
DISCONNECT THE BATTERY BEFORE YOU START.
You must disconnect/remove/move:
1. The fuel hoses going to the fuel rail, both
pressure and return. They aren't long enough when you jack the motor up so you
run the risk of stretching and breaking them. Depressurize the system at the
test port before loosening. Also, a tip: open the gas cap first to vent any
pressure in the tank, otherwise the pressure will force out fuel from the lines
when you disconnect them... I had almost a quart come out of the hoses until I
realized that the pressure in the tank was forcing all the fuel out! I opened
the cap and the flow stopped.
2. Pop the ECM wire harness gutter on the DS valvecover off so it can slide
forwards when you jack the motor up, or else it will smash itself against the
wiper motor. It's easier to remove the two 10mm nuts and lift the guide off the
studs rather than pulling the steel guide off the valvecover-- it's a PAIN to
get back on, just not enough slack. Just loosen the nuts and lift the guide off
leaving the steel attachment on the grooves on the valvecover.
3. Loosen/move the EGR solenoid bracket and sparkplug wire loom clip on the DS
valve cover, or it will gouge into the wiper motor cover when you jack the motor
up. My wiper motor cover now has a nice slice in it from the bracket when I
jacked the motor up... oops.
4. Remove the crossover pipe and tranny inspection cover (duh!)
5. You don't have to remove the starter, but it makes things MUCH easier with it
out of the way. It only takes 2 minutes to remove, and it will save you grief
when you try to snake the oil pan off (and on) around the pickup.
6. Remove the nuts and move the little plastic wiring gutter at the front of the
motor under the harmonic balancer so it doesn't snag on the oil pan when you try
and remove it.
7. You need to unbolt your intercooler shroud from the intercooler, or when you
jack the motor up you'll bend the crap out of it against the sway bar. I
completely removed my intercooler so the shroud was in no way connected to the
motor... only took 15 minutes, and the added room and light up front when the
intercooler is out is helpful. Again, one of those things you don't have to do
but makes the job MUCH more pleasant!
Now the good stuff. Remove the motor mount bolts and jack the motor up... I used
a piece of 1" plywood on my jack and jacked the motor up under the oil pan.
The piece of wood was bigger than the pan to distribute the load. To hold the
motor up I slid 2" x 3" blocks of wood between the motor mount and
frame perches then set it down and removed the jack. A 1" thickness of wood
between the mount and the perch will hold the motor high enough to get the pan
of easily. See the picture below.
For the actual installation... use the correct sealant on the block to cap
surface. The GM shop manual recommends a specific sealant. Air can't get in
between the cap and block mating surfaces, so RTV won't cure. You need an anaerobic
sealant, which is what is called out in the GM shop manual. The book calls out
#1052756, an anaerobic sealer, which cross-references to Permatex Anaerobic
Gasket Maker. (thanks to the guy at the parts counter at my local dealership for
looking that up.) You'll also want to get the Surface Prep and Accelerator for
the sealant... they're not cheap-- about $12 for the sealant and $15 for the
Prep/Accelerator.
There's a great deal of debate on how to seal the sides of the cap to the block.
Some people fill the cavities with RTV, some use the side seals and pins. I
*did* use the side seals included with the Fel-Pro rear main (not RTV), and so
far, so good. Here was my procedure:
1. Apply grease to the new rear main seal. (break in lubrication for it) Pack
the grease into the seal's lip. Forget this and you'll run it dry and burn it up
on the first startup!
2. Roll the upper half of the rear main into the motor (clocked 1/4" from
lining up with the seam) and put the other half of the seal in the cap... make
sure you have the lip on the seals facing the right way!
3. Clean cap and block sealing surfaces with MEK (or any other suitable solvent)
and let dry
4. Apply surface prep/primer to block surfaces using a Q-tip. The spraycan is
messy and I don't know how the bearing surface would like being sprayed with
this stuff.
5. Apply the anaerobic sealant to the top and sides of the cap opposite the
groove for the side seals. You only want a VERY thin smear of the stuff on the
top of the cap, otherwise it will squish out when you tighten the cap and go
places you don't want it to, like the bearing.
6. Apply a light coat of anaerobic to all surfaces of the side seals and place
into cap. Place the seals 1/8" or so ABOVE the machined surface of the cap.
They'll be driven flush when you put the cap in, and better to have them start
high and end flush than to start flush and get pushed down when you install the
main and you'll be unable to push them up completely, so you'll have to pull the
cap, clean/prep everything again and do it over. (Again, don't ask how I know
this)
7. Wipe a little fresh oil on the bearing, make sure it's clean and free of
debris one last time, then install the cap, and snug the bolts. Lightly tap the
cap with a deadblow mallet to ensure it's fully seated.
8. Push up firmly on the side seals to make sure they're seated, then lightly
paint the pins for side seals with the anaerobic sealant and drive them into
place.
9. Torque the cap bolts to spec, working up to the final torque number in
several steps.
10. Trim side seals flush with cap/block surface.
That's it... I let it dry for 48 hours, then put the pan back on (torque to 89
in-lb), lower the motor back down, and put everything back together.
So far, not a single drip... and I hope that's how it stays!
Here are a few pictures of the process.