rear main seal install ? 340/416

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Had no response in the Q&A section so I'll try here !
Any tips on installing the rear main seal on a 340 ? I'm getting tired of oil leaks. 3rd time fixing this. I can't tell if it's the rear main or the oil pan gasket that's leaking. It drips off the bell housing. Oil sending unit is dry. Can't see the cam plug. The rubber seal on the rear had a tear about a 1/2" at the top right side when I pulled the pan out. The clutch hasn't started slipping yet. would too much oil preasure cause an oil leak ? 90 psi @ start up and about 50 when hot at idle. I know too much preasure will expand the oil filter or blow it apart.

Thats a fairly high oil pressure(more than I would
run).... check the crank in the seal area REAL good
I also put a dab of silicone at the edge of the seals
before I place the cap on

I took the oil pump out and removed some of the washers I added to bump up the preasure. I primed it in the vice and now the oil guage reads 75 psi cold with 10 w 30. I usually install main seal with a dab of oil on it and slightly stagger it with 1/2" of the seal sticking out of the block then 1/2" of the seal sticking up on the opposite side of the cap. Then dab the ends with silicone along with the corners of the pan. Maybe the oil on the seal is part of the problem ? And I may have torn the rubber oil pan seal on last install.

That was my main concern to use oil or silicone when installing main seal ?

Thanks Mr P

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/18/11 04:05 PM

I think this was my problem. The last kit I pirchased had the tabs seperate from the main seal. Can't remember what company. I didn't cut them off though. I have the new main seal which are the brown seals in this pic. They are Fel-pro #40181. They came with no tabs on them and no tabs in the box.

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/18/11 04:39 PM

Will the fel-pro black silicone that's in the pic work ok to seal it ?

Posted By: MR_P_BODY

Re: rear main seal install ? 340/416 - 04/18/11 04:40 PM

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I think this was my problem. The last kit I pirchased had the tabs seperate from the main seal. Can't remember what company. I didn't cut them off though. I have the new main seal which are the brown seals in this pic. They are Fel-pro #40181. They came with no tabs on them and no tabs in the box.

In your case you will have to fill the grooves for
the wings with silicone or Right Stuff but leave a
small mound for a contact point.... the reason I
dont like to rotate the seal is the factory spent
MANY man hours to find a way to cut down the warranty
cost issues with the old style(no wings) and they
came up with the wings.... you never seen a factory
seal rotated..... again... JMO.... I had to replace
the pan on my Jeep(rusted out) and I had to cut the
wings off due to the seal was made backwards and on
a 4.0 engine the wings are different sizes... with
silicone at the joints its bone dry and thats been
over a year and half now

Posted By: MR_P_BODY

Re: rear main seal install ? 340/416 - 04/18/11 04:44 PM

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Will the fel-pro black silicone that's in the pic work ok to seal it ?

It should but make sure the surfaces are DRY from
any oil(oil the crank so it doesnt stick to it and
tear up the joints)

Posted By: Moparnut426

Re: rear main seal install ? 340/416 - 04/18/11 04:53 PM

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I think this was my problem. The last kit I pirchased had the tabs seperate from the main seal. Can't remember what company. I didn't cut them off though. I have the new main seal which are the brown seals in this pic. They are Fel-pro #40181. They came with no tabs on them and no tabs in the box.

I have had great luck using the 318 magnum 1 piece gasket. In all cases you have to modify the oil pan to take the tab bump out of the pan rails so the gasket matches the pan. Easy to do with any hammer and dolly, and a welder. None of the 340s or 318s I built have leaked. I with MrP and never stagger the seal. Just made a headache for me in the past.

I also have a high oil psi engine, but no leaks at all. SOMEDAY ill shimm the pump, but for now Im gonna just run 10w40 oil.

Kasey

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/18/11 04:54 PM

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Will the fel-pro black silicone that's in the pic work ok to seal it ?

It should but make sure the surfaces are DRY from
any oil(oil the crank so it doesnt stick to it and
tear up the joints)

Thanks.

I have to go to town so I will look for "The Right Stuff" while I'm there. Now I will clean parts and oil the crank.

Posted By: roadhazard

Re: rear main seal install ? 340/416 - 04/18/11 05:47 PM

For all you guys using Sillycone on your rear main seals

what do you think that will actually accomplish

Do Not use any sealers on the rear seal itself unless you want to create potential issues

You have the rear main seal offset in the cap WAY TOO MUCH

another potential issue.

For the situation at hand with the motor in the car I recommend offsetting the seal 1/8" (.125") with assembly lube on the back side so it will rotate into position with the other half when the main cap is torqued. Use plenty of assembly lube on the seal lip AND crankshaft as it actually takes a long time for oil to reach that area upon initial start up.

The only reason for offsetting a seal is to align the main cap groove with the groove in the block. The seals must mate perfectly square to each other or there WILL be a leak. Main cap to block alignment should always be checked and corrected before any block work is done to the mains, then a referance mark should be placed on the block and cap for proper alingment for assembly. This will eliminate the need to offset the seal.

Just speaking from over 20 years of specializing in automotive oil seals so take it FWIW

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/18/11 09:21 PM

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Quote:

I think this was my problem. The last kit I pirchased had the tabs seperate from the main seal. Can't remember what company. I didn't cut them off though. I have the new main seal which are the brown seals in this pic. They are Fel-pro #40181. They came with no tabs on them and no tabs in the box.

I have had great luck using the 318 magnum 1 piece gasket. In all cases you have to modify the oil pan to take the tab bump out of the pan rails so the gasket matches the pan. Easy to do with any hammer and dolly, and a welder. None of the 340s or 318s I built have leaked. I with MrP and never stagger the seal. Just made a headache for me in the past.

I also have a high oil psi engine, but no leaks at all. SOMEDAY ill shimm the pump, but for now Im gonna just run 10w40 oil.

Kasey

Do you have a part # on that one piece pan gasket ? The parts store I went had one but it said it is used on the 318/360 motor. I asked for a 94 dodge ram application. The one piece I have fits the 360 (1975 LA) I'm building right now. No luck with the 340/318 1 piece.

Posted By: Moparnut426

Re: rear main seal install ? 340/416 - 04/18/11 09:32 PM

ILL HAVE TO DIG.

im callin my mopar part manager now.

Posted By: Moparnut426

Re: rear main seal install ? 340/416 - 04/18/11 09:41 PM

OK,

the 318 fel pro gasket is FPG 0s34408R
the 360 fel pro gasket is FPG 0s34409R

Kasey

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/18/11 09:47 PM

Quote:

For all you guys using Sillycone on your rear main seals what do you think that will actually accomplish
Do Not use any sealers on the rear seal itself unless you want to create potential issues

You have the rear main seal offset in the cap WAY TOO MUCH another potential issue.

For the situation at hand with the motor in the car I recommend offsetting the seal 1/8" (.125") with assembly lube on the back side so it will rotate into position with the other half when the main cap is torqued. Use plenty of assembly lube on the seal lip AND crankshaft as it actually takes a long time for oil to reach that area upon initial start up.

The only reason for offsetting a seal is to align the main cap groove with the groove in the block. The seals must mate perfectly square to each other or there WILL be a leak. Main cap to block alignment should always be checked and corrected before any block work is done to the mains, then a referance mark should be placed on the block and cap for proper alingment for assembly. This will eliminate the need to offset the seal.

Just speaking from over 20 years of specializing in automotive oil seals so take it FWIW

I can only check the seals to see if they mate. That doesn't mean they will mate when they are installed.

Main cap to block allignment I did not check.

Motor was built 3 years ago.
So if both of these issues are off and I do not use sillycone, chances are I will have a leak. But if I use sillycone (silicone) in both thes places, are you saying there is more potential for a leak ? By the way "The Right Stuff" is the wrong price. $20 for a 4 oz tube.

Posted By: Moparnut426

Re: rear main seal install ? 340/416 - 04/18/11 09:55 PM

Quote:

Quote:

For all you guys using Sillycone on your rear main seals what do you think that will actually accomplish
Do Not use any sealers on the rear seal itself unless you want to create potential issues

You have the rear main seal offset in the cap WAY TOO MUCH another potential issue.

For the situation at hand with the motor in the car I recommend offsetting the seal 1/8" (.125") with assembly lube on the back side so it will rotate into position with the other half when the main cap is torqued. Use plenty of assembly lube on the seal lip AND crankshaft as it actually takes a long time for oil to reach that area upon initial start up.

The only reason for offsetting a seal is to align the main cap groove with the groove in the block. The seals must mate perfectly square to each other or there WILL be a leak. Main cap to block alignment should always be checked and corrected before any block work is done to the mains, then a referance mark should be placed on the block and cap for proper alingment for assembly. This will eliminate the need to offset the seal.

Just speaking from over 20 years of specializing in automotive oil seals so take it FWIW

I can only check the seals to see if they mate. That doesn't mean they will mate when they are installed. Main cap to block allignment I did not check. Motor was built 3 years ago.
So if both of these issues are off and I do not use sillycone, chances are I will have a leak. But if I use sillycone (silicone) in both thes places, are you saying there is more potential for a leak ? By the way "The Right Stuff" is the wrong price. $20 for a 4 oz tube.

I dont personally use the right stuff, cause its priced like gold. I do however like the stuff from Ford for the 7.3 powerjoke. Its grey and comes in a short caulk tube for 7.80 ish. Dosnt have a very long shelf life if you cut too but a hole in the tip, so I only cut 1/16" hole in the tip. Its kinda thick, but seals like yamabond. VERY good sealant.

Kasey

Posted By: roadhazard

Re: rear main seal install ? 340/416 - 04/18/11 10:16 PM

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I can only check the seals to see if they mate. That doesn't mean they will mate when they are installed. Main cap to block allignment I did not check. Motor was built 3 years ago.
So if both of these issues are off and I do not use sillycone, chances are I will have a leak. But if I use sillycone (silicone) in both thes places, are you saying there is more potential for a leak ? By the way "The Right Stuff" is the wrong price. $20 for a 4 oz tube.

They will mate properly if you offset them 1/8" (.125") and NOT the 1/2" or so that appears in your above photo

I only suggest the offset because your motor is together and there is no way to determine the seals will be aligned when the main cap is torqued.

Sillycone Will Not cure the problem of the seal halves not mating properly, trust me. When the main cap is torqued where do you think the sillycone oozes out to?........ Little hint, between the seal and the crankshaft

Only assembly lube should be on the seal (back side and seal lip). Only place for sealer is on the main cap seals if they are of the design that are seperate from the seal itself. (See Photo)

Attached picture 6591036-#9340.jpg

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/18/11 10:41 PM

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OK,

the 318 fel pro gasket is FPG 0s34408R
the 360 fel pro gasket is FPG 0s34409R

Kasey

I checked the local parts store and both gaskets are big in front and small in the rear. Remember, this is a 1970 340 I'm working on. The pan uses the same size seal front and rear.

Posted By: Moparnut426

Re: rear main seal install ? 340/416 - 04/18/11 11:03 PM

Dont know then, Ill have to dig through 3 years of notes. May have used a newer front timming cover or something. But I know i built 1 340 2 360s and used 1 piece gaskets.

Ill keep digging..

Kasey

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/18/11 11:14 PM

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Dont know then, Ill have to dig through 3 years of notes. May have used a newer front timming cover or something. But I know i built 1 340 2 360s and used 1 piece gaskets.

Ill keep digging..

Kasey

Thanks

I think the 1 piece would be less likely to leak compared too the 4 piece.

Posted By: MR_P_BODY

Re: rear main seal install ? 340/416 - 04/18/11 11:17 PM

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Quote:

Dont know then, Ill have to dig through 3 years of notes. May have used a newer front timming cover or something. But I know i built 1 340 2 360s and used 1 piece gaskets.

Ill keep digging..

Kasey

Thanks

I think the 1 piece would be less likely to leak compared too the 4 piece.

As far as I know they only make the 1 piece for the
360 only

Posted By: Moparnut426

Re: rear main seal install ? 340/416 - 04/18/11 11:26 PM

Well I just ran accross my notes on the 2 340s I built, and BOTH engines were dirt late model engines, and BOTH blocks were 360 blocks with callies spacers, so that answers that. That kinda sucks. I knew I had them speced at 340" and they are, just older 360 blocks. Sorry,

Someone needs to do this then. The fella on here who specializes in seals and gaskets should try to get the ball rolling maybee?

Kasey

Posted By: roadhazard

Re: rear main seal install ? 340/416 - 04/18/11 11:30 PM

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Well I just ran accross my notes on the 2 340s I built, and BOTH engines were dirt late model engines, and BOTH blocks were 360 blocks with callies spacers, so that answers that. That kinda sucks. I knew I had them speced at 340" and they are, just older 360 blocks. Sorry,

Someone needs to do this then. The fella on here who specializes in seals and gaskets should try to get the ball rolling maybee?

Kasey

I'll take donations starting at 10K to do those

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/18/11 11:43 PM

Quote:

They will mate properly if you offset them 1/8" (.125") and NOT the 1/2" or so that appears in your above photo
I only suggest the offset because your motor is together and there is no way to determine the seals will be aligned when the main cap is torqued.

Sillycone Will Not cure the problem of the seal halves not mating properly, trust me. When the main cap is torqued where do you think the sillycone oozes out to?........ Little hint, between the seal and the crankshaft

Only assembly lube should be on the seal (back side and seal lip). Only place for sealer is on the main cap seals if they are of the design that are seperate from the seal itself. (See Photo)

You make a good point about the silicone oozing out on the crank and the offset.

I just want to make sure it won't leak again. That's why I ask so many questions. I appreciate your input along with everyone elses.

I've been wrenching on these mopars for over 25 years but not afraid to admit I don't know everything about them and have made my share of mistakes. Thanks again.

Posted By: roadhazard

Re: rear main seal install ? 340/416 - 04/18/11 11:50 PM

That's what this forum is all about my friend

I've had so many people help me out on numerous occasions.

Maybe next time you will have one of my seals in there

Greg

Posted By: krw71ragtop

Re: rear main seal install ? 340/416 - 04/19/11 12:06 AM

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Well I just ran accross my notes on the 2 340s I built, and BOTH engines were dirt late model engines, and BOTH blocks were 360 blocks with callies spacers, so that answers that. That kinda sucks. I knew I had them speced at 340" and they are, just older 360 blocks. Sorry,

Someone needs to do this then. The fella on here who specializes in seals and gaskets should try to get the ball rolling maybee?

Kasey

Now I can stop looking for something that don't exist

Thought the auto parts store guys were smoking to much

My notes must not be as organized as yours. Would have taken me hours to look through mine. Plus this dial-up I have takes forever to respond.

Posted By: HotRodDave

Re: rear main seal install ? 340/416 - 04/19/11 03:25 PM

You guys are paying way too much for right-stuff

I buy a big tube for my normal caulk gun and it costs $20 bucks. I have even glued oil pans on with nothing but right stuff and they are some of the driest engines I have seen years later. I don't stagger the seal and I don't put sealant on the seal it self, just the groove.

Posted By: Moparnut426

Re: rear main seal install ? 340/416 - 04/19/11 04:54 PM

Quote:

Quote:

Well I just ran accross my notes on the 2 340s I built, and BOTH engines were dirt late model engines, and BOTH blocks were 360 blocks with callies spacers, so that answers that. That kinda sucks. I knew I had them speced at 340" and they are, just older 360 blocks. Sorry,

Someone needs to do this then. The fella on here who specializes in seals and gaskets should try to get the ball rolling maybee?

Kasey

Now I can stop looking for something that don't exist Thought the auto parts store guys were smoking to much
My notes must not be as organized as yours. Would have taken me hours to look through mine. Plus this dial-up I have takes forever to respond.

I did run accross my notes, and it was easier to call the 2 guys up and just ask them.

rear main seal install ? 340/416