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pan gasket


sweetpotato

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It's not necessary if the flange on the pan is straight. Over the years many pans have been over tightened and the pan between the bolt holes has been warped. Check your pan flange with a straight edge if it's nice and flat use a sealant or not, your choice. If it warped between the holes use the appropriate tools and straighten it. Then use sealant or not your choice but don't over tighten the bolts. I think the book says 15 FT#'s...........Bob

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My methods:  glue the pan gasket to the pan with weatherstrip cement, then install dry or use anaerobic sealer or  brown gasket cement; use brown gasket cement or anaerobic sealer on both sides off the timing cover gasket.  Seal the bolt threads on all since they either go into a water or oil cavity.  Don't use RTV unless you want it to look like a  Chevy engine.

Willie

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Hadn't thought about the bolt threads. Thanks for the reminder. The pan gasket I have on now I installed only about a year ago and it is seeping oil. Can't remember what sealant I used on it, probably permatex but don't know if anaerobic (is all permatex anaerobic?). I'll recheck straightness between bolt holes.

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Good question.  The installation process of the pan is important to eliminate having a leaker later on.  The best way to create a leaker is to do two things.  The first is to yield to the urge to apply gasket cement to both sides of the gasket or just plain applying  too much.  If you must apply any cement then what is needed is only a small tacking / sticking amounts dispersed in a spotting fashion around the perimeter of the pan's flange as holding agent and just enough to hold the gasket in place while reinstalling it.  The gasket itself is the sealer and is designed to seal the mating surfaces as opposed to squeezing a bunch oozing sealant and sandwiching the components together.  

 

The second sure way to create a leaker is to over tighten the pan bolts.  No Gorilla arms needed here.  We use a standard length 1/4 inch drive winding speed wrench on these bolts first in a sequenced mating round, like one would do installing a wheel, then a final sequenced just to snug round enough to mate the bolt head to the metal flange and seat the gasket.  Then walk away. Over torqueing causes more leaks than anything else.  

 

To true the pan flanges and the indented bolt holes which result from the process of installing and tightening a pan into place tends to distort the bolt hole openings. To "true" a pan flange, we set the pan onto our metal flat and straight shop bench with the inside of the pan facing down and place 4 separate moveable 6-inch or so lengths of 3/16 thick aluminum straight edge between the bench surface and under the flange edge. Then take a 1/2 inch socket, turn it over to the flat end and using a light hammer, gently tap ounce or twice to flatten and true the distorted bolt holes while working around the entire perimeter of the pan flange.  Then we take a proven straight edge and run it under the pan with a shop light to see if the overall flange itself is wavy, twisted and/or crowned. The flange can be trued in this fashion as well. We do this same procedure when installing valve covers and only apply if needed any adhesive/sealers in a tack fashion just enough to serve once again as a holding agent as the gasket is the sealer not the gook that comes out of a tube.

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Also you can make your own pan gasket from cork/rubber sheet.  I used a thicker material than the stuff supplied, which might give some room to tighten later if leaks develop.  Unroll the sheet on some plywood or cardboard and placing the pan with some weight on it drill 5/16 holes in the sheet (the holes will be a little undersized), cut the outside with a utility knife.  Turn the pan and gasket over, place enough bolts in the undersized holes to keep the gasket in place and then cut out the inside.

Where is yours leaking?  On the early nailheads there is a plugged hole drivers' side (mid front) of the block/pan mounting surface.  Machine shops will often remove the plug and not replace it leaving a very thin mating surface.

Willie

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Good pointers.  On my old targa I bought silicon gaskets over 12 years ago and still reuse them every time when performing my routine valve lash .004 mm adjustments necessary on these air cooled engine.

 

Makes me wonder why some outfit has not marketed silicon gaskets for an overall GM, Ford, Chrysler etc product line instead of just cork, rubber or what have you.  Of course on the other hand this no doubt would seriously take a bite into their new gasket turnover inventory rates and sales since folks could just reuse these fatter yet better sealing silicon gaskets over and over again.

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I appreciate all this. Thanks for taking the time. My pan gasket was mostly leaking toward the front, probably in the area of the timing cover. Putting it back together this time will definitely be easier and I should do a better job as I have removed the radiator and replaced the timing cover gasket and seal. Makes getting at the front bolts a little easier. Found out that there is one bolt on the timing cover you can't get at without removing the water pump. It gave me a chance to clean everything up and repaint most everything on the front end

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One more thing.  Since I have the pan off I'm going to check the clearance on the oil pump.  I haven't put a good pressure gauge on it but the one in the car shows near the top cold and it drops off to near the bottom hot.  Makes me nervous to look at it but the rocker arms oil o.k. and no other obvious oil pressure problems.  I don't know if the oil pump has a gasket or not but I understand it can be run without one if you need to tighten up the clearance.

I'm also thinking about trying to do the rear seal while the pan is down but I haven't convinced myself that is a great idea yet.

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Yes do the rear seal.  To help you out make sure to loosen up on the foreword main journal caps so the crank drops down ever so slightly.  This will allow more clearance when removing and installing the rear main seal.  We like using Best Gasket's polymer gasket and make sure to allow the side tabs of the seal components to stick up past the block boss as directed in the installation directions.  Not dropping the forward main journal bolts can cause binding when attempting to reinstall the new rear main seal components thereby causing failure and leakage.  Keep us posted on the rear main seal install if you decide to go for it.

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 Bob, if there is a groove worn in the balancer where the seal rubs, it can be sleeved. And if using a modern seal, be sure the "lip" is pointed in towards the engine. Mine is leaking, I think, and cannot remember which way I installed the bugger.

 

  Ben

  There is definitely a slight groove there. I mic'd it and the lip of the new seal still tightens up on it in the groove area. Can it be welded and re-turned?
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Yes do the rear seal.  To help you out make sure to loosen up on the foreword main journal caps so the crank drops down ever so slightly.  This will allow more clearance when removing and installing the rear main seal.  We like using Best Gasket's polymer gasket and make sure to allow the side tabs of the seal components to stick up past the block boss as directed in the installation directions.  Not dropping the forward main journal bolts can cause binding when attempting to reinstall the new rear main seal components thereby causing failure and leakage.  Keep us posted on the rear main seal install if you decide to go for it.

 

Buick Man: I think I will order the Best Gasket rubber seal. I don't see any directions on the package, maybe they are on the back.

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Yes good choice. It is neoprene and has a good runout amount oversize to accommodate some imperfections.  Best Gasket also sells the front timing cover seal which has beed eluded to already.  Install this into the timing cover using a bench shop press.  If you do not have one, take it to a machine shop and make sure the seal edge is curved inward as mentioned.  Regarding the wear groove on the balancers crank snout that this seal rides upon, the snout of this can have a cap/sleeve installed over it.  NAPA sells them as this is where I got mine.  Don't have the part number right off hand but could look it up for you if you need it.  To install correctly, upon applying some red loc-tite to the outer perimeter of the snout, you very carefully and with even fitting and balance, gently tap or better yet by using a shop press, evenly press the sleeve over the balancer snout then carefully clip off the pre-indented rim portion of the sleeve.  Which ever method you use the sleeve MUST be press evenly onto the snot.  When pressing the sleeve on, first do a trial mock up fitting of the balancer with the timing cover temporarily installed after you have installed the timing cover crank seal as just describe.  What you will be accomplishing here is to note and measure the exact area of the balancer snout the timing cover crank seal rides.  Note this and draw up a sketch.  You will then transfer this data to the balancer snout itself so you will know exactly just how far to press the sleeve onto the snout so the seal will ride centered on the sleeve as the snout allows.  This install technique also insures a proper seal.  With all of this, what you then have is a clean and even surface on which the seal can ride.  This this I have done to mine and it has work out great.  

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The sleeve is called a shaft repair sleeve kit; sometime simply 'shaft'.  They work well, but are relatively expensive, so work carefully or pay a machine shop.  A neoprene seal is a good choice for the timing cover, but not  a 2 piece for the rear main.  All that I have installed and heard about have failed!  Even those installed carefully with the crankshaft removed.  Parts vendors will tell you they work great, but they probably have not used one and will not suffer the grief of a failure.

Willie

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Never had one fail but I suppose that is possible, but saying everyone installed has failed is a very high coefficient of coincidence.  I suspect something else is going on here.  One possibility of repeating a failed install of a 3 piece neoprene seal is to not correctly accommodate the side seal ends.  They need to extend proud above the bearing boss.  This is where many fail as folks either are ignorant of this fact or trim them flush. 

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Now I'm getting worried. I've already ordered it. Could you elaborate on that Mike? What do I look for?

The grooves in the block and main bearing cap were not machined to a consistent depth since the original rope seal did not need that much precision.  I have no idea what the 'proper' depth would be for a neoprene seal to work.

Failures (100%) 322 nailhead (3), 248 straight eight (1), 401 nailhead (1)...others have reported success with the later nailheads though.  And it is not just a little leak to be tolerated.  On initial startup and stationary idling everything will look good, but when driving and oil in the pan sloshes to the back, you will have a massive gusher.  

People more flexible than me should experience the joy of redoing a rear main seal... and headliner and convertible top...

Willie

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Well, I guess I will go ahead and install the rubber seal.  This is a straight 8.  I'm getting so good at dropping the pan I'll go to plan B if it doesn't work.  I'll install the pan with the block side of the gasket dry so I can do a quick change if necessary.  At my age labor is not an issue.  If I wasn't working on the Buick I'd be watching old movies on TCM.

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Bob:  Just go to this link and buy these Archie Goodwin Nailhead rebuild articles hosted on Web Rodder. They are very good, detailed and well explained.  The link below is to Article 6 in a series of 1-10 in rebuilding a nailhead and I know you have the straight eight but the theory is the same :

 

http://webrodder.com/article/buick-nailhead-hauler-part-6-crank-installation-timing-set

 

Then many of your questions and worries will be null and void.

 

Good luck

Edited by buick man (see edit history)
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  • 2 weeks later...

Got it all back together and I have about 200 miles on it including a long Fourth of July parade today. No leaks. I sleeved the balancer hub, used a Best gasket rear seal kit and a new front seal. Carefully trued the pan, especially around the bolt holes which had been seriously over-torqued in the past. My 1949 Delta table saw top makes a great surface for straightening oil pans. Took the oil pump cover gasket out and threw it away. Good pressure now.

I think the Buick was more popular in the parade than my Model A, especially among geezers my age who seem to identify better with 1953 than 1930.

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