Rear Main Seal Replacement (4.0)

Rcroane said:
So which is it? Title says conventional and text says blend. Bottle says nothing about blend.
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No idea. I guess the only way to find out (maybe) is to call customer service. Or if anyone else in this forum has any info.
It's also possible that it was conventional in the past and then they switched to a blend recently.
 
The NAPA stuff used to be conventional, verified by @Jerry Bransford. The "synthetic" text on their web page seems to be a more recent change. Since all oil makers are switching almost every product to syn or blend, I suspect this stuff has been switched too.
 
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OldBuzzard said:
The NAPA stuff used to be conventional, verified by @Jerry Bransford. The "synthetic" text on their web page seems to be a more recent change. Since all oil makers are switching almost every product to syn or blend, I suspect this stuff has been switched too.
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Like I said somewhere else, I think Blend is the new Conventional :rolleyes:, but I'm still going to assume that if the bottle doesn't say Blend or Full, it's probably Conventional.
 
OldBuzzard said:
And like I said somewhere else, if it doesn't say, you're just guessing. Is that what you want to put in your TJ?
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Ok, but I think it's a very reasonable guess. I've yet to see a brand that actually says it is conventional on the label. The only confirmed cases of conventional I've seen say nothing on the label.
 
OldBuzzard said:
The NAPA stuff used to be conventional, verified by @Jerry Bransford. The "synthetic" text on their web page seems to be a more recent change. Since all oil makers are switching almost every product to syn or blend, I suspect this stuff has been switched too.
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So my question is if this new napa high mileage oil is then as good as it used to be when it was marked as conventional?
I see a lot of posts in this forum recommending this or that conventional oil, but then it seems like the "conventional" portion recently got dropped by the various manufacturers
 
Just replaced my RMS on my 02, needless to say, I have to do it again. Question is: with the transmission in tact, how will I be able to loosen all main caps to drop the crank a little? There was no way I could get a seal in there without dropping the crank a bit, that's how I ruined the first Mopar seal and had to use a Fel-pro.
 
Mike_H said:
UPDATE:

Having just done this repair on an 04, the How-To guide shows a slightly different RMS than what I found. The difference is in the lower half of the seal. There are two "legs" if you will on the lower seal on EVERY guide and video I've seen. When I opened mine up, the legs are no longer present. The upper and lower seal halves are identical. Unfortunately, I didn't take any pictures, but here is a pic of the seal from Amazon...When you install the oil pan, the FSM states that you need to seal bearing cap to block interface with RTV to account for the "leg" removal.

https://www.amazon.com/gp/product/B000C2E7SM/?tag=wranglerorg-20

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Hey Mike, I know this is a few years back. Your last sentence about the FSM saying that when
you install the oil pan… you need to seal bearing cap to block interface with RTV to account for the "leg" removal.
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Mine is Mopar and doesn’t have legs either. The legs on the other version look like they’d go where the anaerobic gasket maker goes. EDIT: I now see there’s a groove machined in the 97-99 bearing cap.

Where is the “bearing cap to block interface”? EDIT: I think I’ve figured that out now. Blue arrow below. Some of it did ooze out to where the red arrow is pointing last time the seal was done (probably factory.


IMG_2537.jpeg
 
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The rear main bearing is different design in the 97-99 vs 2000-2006.

The 97-99 has a groove for the RMS that has the wings. The 2000-2006 does not have a groove for the RMS with wings. This the two different RMS’s.

97-99 with red arrow pointing at groove that is not on the 2000-2006.

IMG_2542.jpeg


You still need the anaerobic gasket maker for both kinds (all years). You spread it under the wings and on the bearing face on the 97-99 and just on the face on the 2000-2006. Like this.
IMG_2541.png
 
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JMT said:
Hey Mike, I know this is a few years back. Your last sentence about the FSM saying that when


Mine is Mopar and doesn’t have legs either. The legs on the other version look like they’d go where the anaerobic gasket maker goes. EDIT: I now see there’s a groove machined in the 97-99 bearing cap.

Where is the “bearing cap to block interface”? EDIT: I think I’ve figured that out now. Blue arrow below. Some of it did ooze out to where the red arrow is pointing last time the seal was done (probably factory.


View attachment 496895
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Sounds like you answered your own question? Glad I could help, LOL!
 
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Chris said:
This article was originally written by Michael Kang, owner of DailyDrivenTJ.com. I take no credit for this article. Just sharing a great how-to article with the TJ community.



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When the time came for me to replace the leaky rear main seal on my TJ, I searched online for a decent write up. Some of them were ok, but none of them were good enough to really show the potential DIY to see what is really going down with the repair. Besides many were lacking crucial details, explanations and/or without pictures. I decided to bring something that is more than a write up with 5 pictures. You won't be disappointed with the amount of detail shown in this write up.

Anyhow, chances are, if you own 4.0L I6, you will have a rear main seal leaking on you. As shown in the picture above, the symptom is a engine oil leak between the engine and the transmission. This repair costs anywhere from $300 to $600 depending on where you get the repair done. Surprisingly, all the parts only cost around $50. Not saying it is easy to do, but this repair is not all that hard to do it yourself. With the this guide available in DDTJ, you will know exactly what you are getting yourself into as usual.

Tools and Parts Needed

Here are the pictures of the parts you will need to hunt down.

Anaerobic Gasket Maker (it cures when there is no oxygen.)
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Rear Main Seal (2 pieces)
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Oil Pan Gasket (Click on the image to see the part number.)
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Some instruction that were included in the oil pan seal and the rear main seal.
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Job Hours
Takes about 2-6 hours.


Procedure
1. Remove the oxygen sensor from the down pipe. Remove the bolts and nuts holding the down pipe to the header. You will have to move the pipe around so that you can lower the oil pan later.
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2. Drain the engine oil. I have SureDrain by Fram installed on the oil pan.
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3. Chrysler used different sized bolts to hold the oil pan to the engine block. I think they used 1/2 inch and another size. I took several pictures of the bolts and where they are located so I don't I have to remember them where they go back. Here they are, for your reference. Start removing them and put them in a safe place.
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4. Once the oil pan is out of the Jeep, this is what it looks like. Your engine may look different with less brown. My Jeep is 10 years old, JFYI.
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5. Remove the main bearing cap brace by removing 12 bolts. This is the long stick shown in the following picture.
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6. With the main bearing cap brace removed, remove the rear main bearing cap.
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You will have to wiggle the cap loose front to back, not side to side.
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7. Remove the top half of the seal by driving it out of the block. Use extreme caution not to score/dent/scratch anywhere. One small nick or scratch can cause leak and is no longer repairable. As you remove the seal, note the orientation of the seal. The seal is opening towards the front of the vehicle.
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Here is what they look like removed from the engine. The top half and the bottom half is shown here.
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Notice how the old seal has lost its shape. *Blue residue shown on the new seal is wheel bearing grease.
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8. Start cleaning the mating surfaces. Make sure things are cleaned down to the metal without removing any metal. I used old tooth brush with a lot of elbow grease. Make sure there is no oily residue left. This is ABSOLUTELY CRUCIAL for the success of this repair. One little residue of old sealant will cause leak. Oiled surface does not allow the adhesive to adhere properly. I used a paint prepping agent to clean the surface. Pay particular attention to the areas indicated by the arrow.

Before
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After
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While you are cleaning the bearing cap, if the bearing falls out of the cap, put it back on the cap with a bit of grease to go between the two pieces. It only goes in one direction.
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Clean the engine block where the bearing cap mates against free of any residue whatsoever! This cannot be stressed enough! Clean ANY mating surface ABSOLUTELY free of any old sealant and any type of residue!! Remember you have to do this WITHOUT damaging/scoring the metal!
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This is a picture of two pieces of paper towels. Left one is used to absorb the oil from the bottom of the oil pan. The one on the right is virgin oil. There was considerable amount of solid stuck on the bottom of the oil pan.
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9. Start cleaning the oil pan. Remove the old gasket and clean the mating surface with mild wire wheel. I cleaned the surface with paint prepping agent once again. this gets rid of any oil residues left behind.
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Here is how they should look after you are done cleaning.
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10. Install the upper half of the seal after lubing with some engine oil. DO NOT PUT ANY SEALANT ON THIS SEAL! With the seal's lip opening towards the front of the vehicle.

*Here is one crucial detail that every online write up fails to emphasize. As you push in the upper half of the seal, if you do not follow (as you push the seal) the circle channel carefully, you will cut the seal and this will guarantee the rear main seal to leak again.
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So how do you install the upper seal without cutting it up? Fel-Pro included this nifty thin plastic that you wedge between the channel and the seal to keep it from getting cut. *I saw the same seal kit that included this plastic piece, and some did not. Your mileage may vary.
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Notice the orientation of the seal where the mouth of the seal opens toward the front of the vehicle. Once seal is in place, simply pull the plastic out.
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11. Start applying Chrysler Anaerobic Sealant or Loctite 518 on the rear main bearing cap mating surfaces as shown in the following picture. You DO NOT NEED MUCH. It is CRUCIALthat you DO NOT get any of this sealant on the lip of the seal! Make sure you compensate for the spread of the sealant once it is jammed between the surfaces. Put some engine oil on the bearing!!
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*Anaerobic Sealant starts curing after when it is isolated from the atmosphere unlike most RTVs. Some may say they got away with using RTV. They got away. I am not sure if you will. I also noticed the anaerobic sealer had different viscosity compare to the red RTV that I used on the oil pan gasket. BTW it is the factory service manual that is calling for this Loctite 518 or equivalent. There is no Loctite 518 available in the local part store which is the anaerobic sealant. You will have to get this sealant from the dealer.

12. Install the main bearing cap and torque the bolts to 80ft.lbs.
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13. Install the bearing brace and torque the bolts to 35ft.lbs.
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14. Place the oil pan gasket on the pan. I used RTV on the crucial area at the front of the block and where the rear bearing cap. I can use RTV here, because this is to seal something that is not moving against anything. Notice that I used RTV on both the top and the bottom of the oil pan gasket. *MAKE SURE YOU CLEAN THE MATING SURFACE OF THE ENGINE BLOCK FREE OF ANY SEALANT AND OILY RESIDUE! I used paint prepping solvent to clean the surface.
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15. Install the oil pan but while doing so make sure the rear main bearing cap's groove lines up with the oil pan gasket. Also pay particular attention to gasket on the front of the engine. It has built in grooves that has to sit just right. Tighten the bolts to 84in/lbs for the 1/4" bolts, and 132in/lbs for the 5/16" bolts.
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16. Install the down pipe back on the header and install the oxygen sensor back on the down pipe and JUST hand tight it down. It just needs to be on there tight enough so it won't fall back out on its own.
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17. Replace the oil filter and put in 5qt of oil and watch the dip stick to top off. *I learned my jeep even tough it was almost bone dry (which I left it to drain for two days while I was working on the rear end.) it did not take the full 6qts. More like 5 and 1/2 qts total to have it read "Full" on the dip stick.
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18. Enjoy leak free engine! No more oil spots on the driveway! Pat yourself on the back, you saved a few hundred dollars!
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Thank you very much for the information provided. I know this post is old, I have no way to do this job where I live and they just quoted it to me at $875. I'm screwed either way Lol
 
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enmanuelrs9999 said:
Thank you very much for the information provided. I know this post is old, I have no way to do this job where I live and they just quoted it to me at $875. I'm screwed either way Lol
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If the leak isn't very bad you can live with it. Just put a pan or oil obsorbing granules under the area. Use high quality oil like high mileage Mobil 1 which has additives for old seals. It helps. That's what I've done until I can fix it.
 
nitrofalcon said:
If the leak isn't very bad you can live with it. Just put a pan or oil obsorbing granules under the area. Use high quality oil like high mileage Mobil 1 which has additives for old seals. It helps. That's what I've done until I can fix it.
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One more thing. Keep an eye on the oil level.
 
nitrofalcon said:
If the leak isn't very bad you can live with it. Just put a pan or oil obsorbing granules under the area. Use high quality oil like high mileage Mobil 1 which has additives for old seals. It helps. That's what I've done until I can fix it.
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Thanks, I did my oil change a couple of weeks ago and put 10w 30 pennzoil conventional non synthetic. At the moment it doesn't leak much, just a few drops when I return from work or when I arrive. In the same way I want to maintain this car well, I bought it a month ago knowing about the leak, I really didn't think they would price it so high.
 
enmanuelrs9999 said:
Thanks, I did my oil change a couple of weeks ago and put 10w 30 pennzoil conventional non synthetic. At the moment it doesn't leak much, just a few drops when I return from work or when I arrive. In the same way I want to maintain this car well, I bought it a month ago knowing about the leak, I really didn't think they would price it so high.
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Congratulations on your new jeep an welcome to this forum. There's a wealth of good information here. You're young and eager to learn so, you'll do fine! If you decide to do the repair yourself research the videos on net and read everything on this forum. It's not terribly difficult but you need the right tools and some of the fasteners can be stubborn. Also, please complete your profile so know about your jeep. BTW, my leak is similar to yours and I'm in no rush to fix it.
 
nitrofalcon said:
Congratulations on your new jeep an welcome to this forum. There's a wealth of good information here. You're young and eager to learn so, you'll do fine! If you decide to do the repair yourself research the videos on net and read everything on this forum. It's not terribly difficult but you need the right tools and some of the fasteners can be stubborn. Also, please complete your profile so know about your jeep. BTW, my leak is similar to yours and I'm in no rush to fix it.
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Jeeps are sometimes like old Harleys. They like to mark their spot!
 
nitrofalcon said:
Felicitaciones por su nuevo jeep, bienvenido a este foro. Hay una gran cantidad de buena información aquí. Eres joven y tienes muchas ganas de aprender, ¡te irá bien! Si decide hacer la reparación usted mismo, busque los videos en la red y lea todo en este foro. No es muy difícil, pero necesitas las herramientas adecuadas y algunos de los sujetadores pueden resultar difíciles. Además, complete su perfil para conocer su jeep. Por cierto, mi fuga es similar a la tuya y no tengo prisa por solucionarla.
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I had a 2007 Chevy Equinox that gave me a lot of problems with radiator hoses, electro fans and the entire cooling system, with it I learned some mechanics but I think this is something more serious and I have seen a lot of information here but I still think that I need some more practice, for now I'll start with the fan clutch and change the entire cooling system. This is a 2003 Sahara with 130k miles and it seems to have some pretty old hoses. But I'm happy to find this forum, it has a lot of information.
 
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