LA Oil Pan on Magnum

[3406pk]

I have 5.9L Magnum engine in my Duster that has LA oil pan. When I rebuilt the engine, I used the one piece OS34409R gasket with the end pan seals attached. It developed oil leak at front of pan. When I took pan off, I found source of leak. I never noticed the gap at corner during assembly. The obvious solution is to use LA style gasket and end seals. I was replacing gasket with engine still in car, so wanted to use the Magnum style gasket. I cut corners off front pan end seals of LA and glued them into pan, then used the magnum gasket. Rear pan seal of magnum gasket fits fine.

 

[Toluene56]

Common issue, I just use LA oil pan gaskets on my mag block. Works fine no leaks.

 

[318willrun]

I have 5.9L Magnum engine in my Duster that has LA oil pan. When I rebuilt the engine, I used the one piece OS34409R gasket with the end pan seals attached. It developed oil leak at front of pan. When I took pan off, I found source of leak. I never noticed the gap at corner during assembly. The obvious solution is to use LA style gasket and end seals. I was replacing gasket with engine still in car, so wanted to use the Magnum style gasket. I cut corners off front pan end seals of LA and glued them into pan, then used the magnum gasket. Rear pan seal of magnum gasket fits fine.

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thanks!

 

[jbc426]

I had the same issue, and the flap on the front of the one-piece Magnum gasket hid the LA's pan's gap in the corners pretty good. It took me a while to find the source of my oil leak under full throttle.

I used a hammer and body dolly to modify the LA pans notches and put a bit of extra Permatex Ultra Seal at the location.

 

[rumblefish360]

I also used a good bit of permatex to seal up the variances. The one spot that gives me trouble every time is the rear of the oil pan around the crank semi circle. I finally got loaded up with frustration and cut it out and used a LA 360 pan gasket in that spot.

The oil pan gasket was a Mr. Gasket 1 Peace sealed and labeled for the 360. Not a Magnum engine.

 

[MopaR&D]

I noticed the same thing putting a 360 LA pan on my 5.9 Mag with the Magnum 1-piece gasket, I just filled up the spaces with RTV, no leaks from there BUT...

I also used a good bit of permatex to seal up the variances. The one spot that gives me trouble every time is the rear of the oil pan around the crank semi circle. I finally got loaded up with frustration and cut it out and used a LA 360 pan gasket in that spot.

The oil pan gasket was a Mr. Gasket 1 Peace sealed and labeled for the 360. Not a Magnum engine.

I seem to be having this same problem on mine, slight oil leak from what seems to be the rear of the oil pan (flex plate and inside of bellhousing are bone-dry). I think the stamped rib on the LA pan on that semi-circle section doesn't line up well with the Magnum gasket, I noticed that during assembly but just said "whatever" and let it be lol. It leaks 2-3 drops every time I park which isn't quite enough to get me to go under the car and pull the oil pan. My oil level hasn't dropped much at all over the past ~1000 miles so it's definitely a small leak. That's the ONLY leak I have on my Duster though so overall it doesn't bother me much.

I didn't realize they made a 1-piece seal specifically for LA engines...

 

[rumblefish360]

didn't realize they made a 1-piece seal specifically for LA engines...

I haven’t noticed one.
Around the rear main cap the Magnum 1 piece fitted loosely. I chopped that off and used a LA around the rear main cap seal and glued the rest together.

 

[70aarcuda]

LA pan LA gasket
Magnum Pan Magnum Gasket....

even a blind caveman could do it

 

[MopaR&D]

LA pan LA gasket
Magnum Pan Magnum Gasket....

even a blind caveman could do it

I'll use an LA pan gasket if there exists one similar to the Magnum piece with the double lip seal and steel core, I also hate those rubber front seals they always start leaking between the timing cover and pan sooner or later (not in the corners I always put RTV there).

 

[mike heasley]

digging up one from the past. I modified my 360 LA pan and used the magnum 5.2/5.9 gasket. worked fantastic. here are some before during and after pictures of the modified section of the pan.

 

[DumpsterFire]

digging up one from the past. I modified my 360 LA pan and used the magnum 5.2/5.9 gasket. worked fantastic. here are some before during and after pictures of the modified section of the pan.

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Very tempted to do that

 

[mike heasley]

Very tempted to do that

I was too weary of the aftermarket one piece La pan gaskets. And I know how fantastic the Magnum OEM ones seal up and you don't have to fight them at all. I'm never not going to modify a 360 La pan again, if it's off the motor.

 

[JDMopar]

@mike heasley Brilliant idea! Did you leave the filler piece you welded in a little narrow to have a lip to weld to, then grind it to the proper width? If the 98 Magnum pan that's on my motor (from 3500 pickup) won't work in my 88 D100...I will copycat this on a 360LA truck pan. I HATE oil leaks!

 

[mike heasley]

@mike heasley Brilliant idea! Did you leave the filler piece you welded in a little narrow to have a lip to weld to, then grind it to the proper width? If the 98 Magnum pan that's on my motor (from 3500 pickup) won't work in my 88 D100...I will copycat this on a 360LA truck pan. I HATE oil leaks!

I did but I forgot to weld the hole shut that the OEM font gasket locks the tabs into. so I just ended up with a dab of sealer where the tabs went, just incase I didn't have a 100% sealed weld in the inside vertically. since I wasn't focused on sealing the inside, but I should have been paying more attention to that detail.

 

[mike heasley]

@mike heasley Brilliant idea! Did you leave the filler piece you welded in a little narrow to have a lip to weld to, then grind it to the proper width? If the 98 Magnum pan that's on my motor (from 3500 pickup) won't work in my 88 D100...I will copycat this on a 360LA truck pan. I HATE oil leaks!

also on that note I believe you are interchangeable with the magnum pan so you don't have to modify, remember to make sure you have the correct pickup for the pan also. but I'm not an expert on the interchangeability, just more of an informed novice.

 

[JDMopar]

Thanks. I bought the Magnum complete from a 98 3500 dually and it does have a rear sump pan on it. I'm going to do a test fit and see if the existing pan on the Magnum motor fits the 88 chassis. If it does, all I'll do is pressure wash it and paint it. If not, I have a 360 LA rear sump truck pan and pickup that I bought from another member here. I'm hoping the Magnum pan will fit because it is dry as a bone and never leaked a drop. Thanks for the replies.