oil pan gasket and rear main seal(plus a cleaning question)

[jonathon]

I figure my MLK day project will be to do the rear main seal and oil pan gasket.. haven't looked in the oil pan since I got so I figure it can't hurt.. besides a good chunk of my gasket is sticking out the side of the pan I also have a nice leak at the rear main that's probably at least 10-15 years old judging by the sludge that was on the original starter when I replaced it.

Looking at Summit for the seals, they list two different oil pan gaskets.. one being a thick seal and the other a thin. Which do I need(my Blazer is listed in my signature)?

Now as far as cleaning the sludge off the underside of my truck.. what's an easy, but safe way to get it off? I thought about simple green however it is corrosive to aluminum.. and my t-case is aluminum and not sure what else is either. I've got sludge everywhere on the underside.. at least as far back as the trany and front of the t-case

 

[blazin_blazer]

Put a straight edge across the top of the front of the pan, from rail to rail. Measure from that edge to the bottom of the curved part where the seal rides. If it measures 2-1/4", use the thin seal. If it's 2-3/8", use the thick one. i believe that is correct.
however,
they make a 1 piece that is oilpan and 1/2 main seals(so no rtv where rail meets seals), it is metal sandwich w/ metal around the bolt holes so you don't squish it out...in mid/late 70's i think gm went to thick, but i see both listed for 84 so ...i always just try to match size w/ the one that came out, its pretty noticable difference, as most gasket sets have both sizes in them...and put some rtv on the end of seal where the halves come together

edit: oven cleaner from dollar store works ok, as well as engine degreaser, i've used a hi concentrate of dawn (dawn takes grease out of its way) dish soap in a pump up and let soak and use pressure wash at car wash 3-4 times

 

[Jason4x4]

Get the felpro 1 piece oil pan gasket, you will not be dissapointed.

 

[jonathon]

Get the felpro 1 piece oil pan gasket, you will not be dissapointed.

Thats what I am going to use... except they have the thin or thick.

Blazin, I will check it out thanks!

 

[vortec]

my 82's oil pan gasket seems pretty dang thin.

i use brake parts cleaner on almost everything. that stuff is awesome. it degrunges stuff that nothing else will and evaporates with little or no residue. it does strip paint really easily, though.

 

[gettinwestern]

Now as far as cleaning the sludge off the underside of my truck.. what's an easy, but safe way to get it off? I thought about simple green however it is corrosive to aluminum.. and my t-case is aluminum and not sure what else is either. I've got sludge everywhere on the underside.. at least as far back as the trany and front of the t-case

Oven cleaner does wonders on sludge, just be careful with it and wear some good gloves. It is also corrosive to aluminum to a degree, but those warnings are mainly to keep you from spraying it on brightwork. Only thing I've seen that really eats aluminum is caustic soda.