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Oil Pan installation on 350

Discussion in 'Chevy Trucks' started by steven1213, Mar 12, 2008.

  1. steven1213

    steven1213 Junior Member
    Messages: 20

    I replacing the oil pan gasket of a motor I am installing in my truck.
    Does anyone know how much to torque the retaining bolts for the oil pan to my 1981 350 engine? The manual says to torque the bolts to 100 in lbs and the nuts to 200 in lbs but that
    does not make sense to me since to much pressure would screw up the seating of the cork gasket. Thanks for any help.------------Steve
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The specs are in inch pounds Steve. I believe your thinking foot pounds . Thats probably why it sounds like too much to you.

    You can also convert the inch pounds specs into foot pounds...

    The 17 small 1/4" bolts that call for 100 in lbs... would be about 9 ft lbs (same thing)

    The 4 larger 5/16" bolts in the corners that get 200 in lbs... would be about 18 ft lbs. (again, same thing)
  3. steven1213

    steven1213 Junior Member
    Messages: 20

    Thanks for the help B&B. Do you like to put RTV silicone on the cork gasket as well as the rubber seal on the front and the back of the oil pan. I put the silicone at the corners where the rubber meets the cork gasket on the corners and on the outer edge of the rubber seals between the rubber gasket and the oil pan.because that is where it was when I pulled the old one off. I hope I did that right. I will rectify it if I have to since the motor is not installed yet. I am also unclear about how to replace the other seal on the front of the motor behind the harmonic balancer. It looks as though the timing chain cover needs to come off according to the Chiltons manual but my father in law said that I don't need to do that. Can anybody clarify this for me? ----------Thanks again----Steve
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    No problem Steve.

    I never use a continuous bead of RTV on the cork gaskets if thats what your asking. I do use a bit of RTV or gasket glue in order to hold the cork gaskets to the block to prevent shifting, but that's it. I do place a dab at each connecting point between the cork and rubber end gaskets, and across the rubber ones from side to side just like you've done.

    Your "other seal" would be your front crank seal behind the balancer. If you had the oil pan off that was the perfect opportunity to also pull and reseal the timing chain cover as well as install a new front seal. It is possible to change the seal with the cover on but it's not an easy job to do correctly without distorting the cover (thin stamped steel). You have to drive the seal in and it's very easy to distort the cover as the seal fits rather tightly.

    I always install the seals with the cover off so I can support the back side of the cover with a block of wood around the seal cavity. You can try changing the seal with the cover on but if I was in your shoes, I'd pull the oil pan off and pull the front cover off to replace the seal. Also gives you a chance to inspect the timing chain and gears as well. Timing sets are cheap so if you don't know the mileage on the engine your much further ahead to replace them now. You should be able to purchase another pan gasket set, timing cover seal & gasket and a timing set for around $50. Smart move while the engine is out and on the stand IMO...no fun with it in the vehicle if it gives you problems later.
  5. derekbroerse

    derekbroerse 2000 Club Member
    Messages: 2,377

    If you are going to replace the balancer seal, replace it with either an aftermarket 'offset' seal or a stock one with a steel sleeve on the balancer.

    Over time, the original seal can wear a groove in the iron balancer and cause leaks that even a new seal can't fix. The offset seal moves the lip outwards like 1/8" so it rides on an unworn surface of the balancer.

    The other solution uses a common stock replacement seal but a steel sleeve you press on over the balancer stub. Basically accomplishes the same thing.