Magnum Oil pan/gasket fitment issues

JoePole1

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Working on buttoning up the bottom end on my 360 and having issues with the oil pan gasket and pan. When I dry fit the pan I am flat on the block. I have a one piece Magnum oil pan gasket and I understand that the front piece needs to be cut off and replaced with the LA style front at the timing cover. When I fit up just using the LA front piece I have a gap at the pan and I am about a quarter inch above the block on both sides. When I try the one piece Magnum gasket, I am about 3/8 of an inch on both sides but the fitment is better. Still too far away from the block. If I were to tighten up the pan bolts pretty sure it would bend the pan. I am using a JEGS or Summit LA oil pan. Any thoughts on this?

This is the LA front gasket. Notice the gap between the pan and gasket In the corner. Gasket looks straight but pan is curved.

KIMG0123.JPG


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Here's the full Magnum gasket.
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KIMG0126.JPG
 

DionR

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The LA front gasket has pins that are supposed to be pull through those little holes. Sticks in my head that they are different sized pins and holes, maybe the rubber block is a different size side to side as well? And if you reversed it, the pan might fit better?

Just a guess.
 
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JoePole1

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The LA front gasket has a pin's that are supposed to be pull through those little holes. Sticks in my head that they are different sized pins and holes, maybe the rubber block is a different size side to side as well? And if you reversed it, the pan might fit better?

Just a guess.

Hahahahahah. I could not get those pins through the holes. Even tried silicone and pliers so I cut them off. Gasket is correct. Smooth side goes to the crank side.
 

Professor Fate

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Okay, I gotta ask- are you SURE you've got a 360 oil pan and not a 318/340 pan? I've had the wrong ones shipped before...
The 340 pan has the same radius on both ends of the pan- the 360 pan has a larger radius at the rear.
 

DionR

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Hahahahahah. I could not get those pins through the holes. Even tried silicone and pliers so I cut them off. Gasket is correct. Smooth side goes to the crank side.

Seems like I have cut them off before, too. Even when I didn't, seems like they got pull off trying to get them through the holes.

I guess the 2 options are a misformed pan, or bad gaskets. Since you have tried two gaskets, sounds like the pan might be the issue?

Did you try pushing the pan down? Not suck it down using the bolts, just put some weight on it to see if the gasket would squish and make things fit?
 

Professor Fate

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Seems like I have cut them off before, too. Even when I didn't, seems like they got pull off trying to get them through the holes.

I guess the 2 options are a misformed pan, or bad gaskets. Since you have tried two gaskets, sounds like the pan might be the issue?

Did you try pushing the pan down? Not suck it down using the bolts, just put some weight on it to see if the gasket would squish and make things fit?
And oil or smear a light coat of grease on the end seals to help the pan to ease down into place.
 

DionR

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Might set the pan on the motor without any gaskets to see if anything jumps out at you.
 

Bobzilla

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Do NOT cut the front off of the Magnum one piece gasket. No need to. Ever.

Some aftermarket oil pans do not fit correctly with their proper gasket. I recently had a Milodon pan that the little holes for front seal were so far off the rubber would never seal between the pan and timing cover. Similar to why the OP cut those nipples off.

Never use grease, oil, or anything else on oil pan gaskets that prevents RTV silicone from sticking. It will usually leak. The silicone will act as a lube and help it slide in place, then glued it there once dried.

Best bet here is to use the one piece Magnum gasket, fill the corners with silicone, then make damn sure the front rubber part is properly positioned while tightening the bolts down, and tighten a little at a time. The Magnum pan has a wide flat loop on the front where that rubber sits. The LA pan is narrower and usually has an extra ridge on that loop that presses on the wider LA rubber, but the LA rubber has flaps that keep in place.

You need to make sure that front Magnum rubber stays centered until everything is tight, and it usually works.

My pictures of this are all on a flash drive somewhere but I will try to find them when I have time.
 

JoePole1

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Do NOT cut the front off of the Magnum one piece gasket. No need to. Ever.

Some aftermarket oil pans do not fit correctly with their proper gasket. I recently had a Milodon pan that the little holes for front seal were so far off the rubber would never seal between the pan and timing cover. Similar to why the OP cut those nipples off.

Never use grease, oil, or anything else on oil pan gaskets that prevents RTV silicone from sticking. It will usually leak. The silicone will act as a lube and help it slide in place, then glued it there once dried.

Best bet here is to use the one piece Magnum gasket, fill the corners with silicone, then make damn sure the front rubber part is properly positioned while tightening the bolts down, and tighten a little at a time. The Magnum pan has a wide flat loop on the front where that rubber sits. The LA pan is narrower and usually has an extra ridge on that loop that presses on the wider LA rubber, but the LA rubber has flaps that keep in place.

You need to make sure that front Magnum rubber stays centered until everything is tight, and it usually works.

My pictures of this are all on a flash drive somewhere but I will try to find them when I have time.

Makes sense. I try a dry run without the RTV and see how the pan pulls down stopping short of torquing down first and see how it goes. Good to hear from life experience from you guys. Thanks to all.
 

DusTed74

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WOW. I can't believe that there are so many people here that have had the same issues that I'm dealing with right now.
I have tried everything from getting a can of silicone to opening up the holes but those things will not go through.
If anyone out there has a trick for this please let us know.
Ted
 

Bobzilla

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WOW. I can't believe that there are so many people here that have had the same issues that I'm dealing with right now.
I have tried everything from getting a can of silicone to opening up the holes but those things will not go through.
If anyone out there has a trick for this please let us know.
Ted
The holes must be large enough or they will likely tear off. No idea what correct size is, but they are different sizes as someone said. The easiest way I know is to pull through with needle nose pliers. Just get it poking through a little, grab it and pull straight. So far, I never had one tear off.
 

jbc426

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I just hammered the front notches down flat on my LA 360 Milodon oil pan and used the one piece Magnum gasket and a small squirt of Permatex Ultra Seal in all 4 corners of the pan and on the threads of each oil pan bolt on my 5.9 Magnum. It's remained leak free for several years now.

The notches are not altered in this photo, but was easy to do with a small hammer and body block.

The 1 piece gasket has flaps that hide the notches on the LA pans, and I had a mystery oil leak when the car was under heavy throttle. It took me a while to learn to do the method above.

Oil Pan Gaskets (Medium).JPG


Oil Pan pic (Medium).JPG
 

JoePole1

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Got it installed. I followed Bobzilla's instructions. I first installed the pan without the gasket. Noticed that it did not seat on the block due to a slight bow along the long sections of the pan. I also noticed that the pan flanges were also tweaked and not perpendicular to the sides of the pan making the gap look worst than it was. Removed the pan and straightened that out.
I then made sure my pick- up was level with the block rails. It was off a little. I then cleaned the Magnum pan gasket as well as the block/timing cover surfaces. Ultra gray in the corners, gasket down, ultra gray in the corners and the pan notches.
Torqued down center out in steps to 200 inch pounds. Looks good. It will all set up until the install. On to the intake.
Thanks to all.

BTW.....here is my home made pan windage set-up and yes I trial fitted including dip stick.

IMG_20220204_144517_hdr.jpg
 

MassDart

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Do NOT cut the front off of the Magnum one piece gasket. No need to. Ever.

Some aftermarket oil pans do not fit correctly with their proper gasket. I recently had a Milodon pan that the little holes for front seal were so far off the rubber would never seal between the pan and timing cover. Similar to why the OP cut those nipples off.

Never use grease, oil, or anything else on oil pan gaskets that prevents RTV silicone from sticking. It will usually leak. The silicone will act as a lube and help it slide in place, then glued it there once dried.

Best bet here is to use the one piece Magnum gasket, fill the corners with silicone, then make damn sure the front rubber part is properly positioned while tightening the bolts down, and tighten a little at a time. The Magnum pan has a wide flat loop on the front where that rubber sits. The LA pan is narrower and usually has an extra ridge on that loop that presses on the wider LA rubber, but the LA rubber has flaps that keep in place.

You need to make sure that front Magnum rubber stays centered until everything is tight, and it usually works.

My pictures of this are all on a flash drive somewhere but I will try to find them when I have time.


I'm in the process of buttoning up my Magnum swap and putting the 360 LA oil pan on this weekend. Your post was super helpful. I got the kit from Scram Speed which has the timing cover, waterpump, and LA gasket loops. It also included a felt donut which I have no idea where that would go. So just to double check, you're saying just use the Magnum gasket and RTV the **** out of the corners and it's good to go?

Thanks!
 

Bobzilla

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I'm in the process of buttoning up my Magnum swap and putting the 360 LA oil pan on this weekend. Your post was super helpful. I got the kit from Scram Speed which has the timing cover, waterpump, and LA gasket loops. It also included a felt donut which I have no idea where that would go. So just to double check, you're saying just use the Magnum gasket and RTV the **** out of the corners and it's good to go?

Thanks!

The felt donut would be placed in the harmonic balancer itself on an old LA setup. That balancer has a large thin dust shield, and the donut fits inside it. Do not use the donut on a Magnum balancer.

If you place a clean, dry, one-piece Magnum gasket on the LA style oil pan you will see how much gap there is where the LA oil pan has a notch on both sides at the front. That gives you an idea how much silicone to use to fill gap. It is not as much as people make it out to be and worry about. Then, you also use a small dab or smear at the timing cover parting line at the block, just as you would on a LA gasket. I also put a small smear in the corner of the timing cover, where the loop meets the flats.

Looks like I never went back previously into this thread and added pictures.
 

MassDart

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The felt donut would be placed in the harmonic balancer itself on an old LA setup. That balancer has a large thin dust shield, and the donut fits inside it. Do not use the donut on a Magnum balancer.

If you place a clean, dry, one-piece Magnum gasket on the LA style oil pan you will see how much gap there is where the LA oil pan has a notch on both sides at the front. That gives you an idea how much silicone to use to fill gap. It is not as much as people make it out to be and worry about. Then, you also use a small dab or smear at the timing cover parting line at the block, just as you would on a LA gasket. I also put a small smear in the corner of the timing cover, where the loop meets the flats.

Looks like I never went back previously into this thread and added pictures.


Much appreciated!
 
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