rear main seal

[dj5]

I just swapped in my new radiator and while getting the coolant in the engine realized there was an oil leak, took a look...its my rear main seal.
I lost 2 quarts in a matter of 30 miles and its burning on my exhaust.

 

I'm not competent enough to do this type of thing. would about should I be looking at in costs reasonably to get this fixed?

[87MJTIM]

You will be surprised what you can do with a little reading up on the procedure.  ( I am a CPA, but I do much of my own mechanincals.  I just swapped trans in a CJ7 with a lot of reading.)

 

First, do you have space to work?  You picture looks like a community parking lot.

 

Note: it is a dirty job.  Have on old clothes and a hat for your hair, like a hair nets the cafeteria ladies wear.  Also, eye protection since you will be on your back looking up alot. Put a large piece of cardboard under the truck.

 

1. Disconnect battery cable

1a. Jack up the truck.

2. Put jack stands under the frame rails.  Let the front axle hang down to give you room to work.

3. Drain the oil.

4. Remove starter.  2 bolts and a wire.

5. If you have a front skid plate, remove it.  4 bolts.

6. start undoing the oil pan bolts.  Have a piece of cardboard ready.  As you remove the bolts, push them through the cardboard in the same position as the pan.

7. Once all the bolts are off, pull off the pan.  You may need to "gently pursued it" off.  Use a rubber mallet to tap it and rock it side-to-side.  DO NOT PRY IT OFF.  You may bend the rim of the pan.  CAREFUL as you lower it down.  The oil pump is hanging down into the pan.

8. At the rear of the engine, remove the last bearing cap.  DO NOT scrape or mark the bearing.  The lower RMS sits into cap.

9. Take a small punch, carefully punch out the upper seal.  DO NOT scrape the bearing!

10 Coat the upper seal in oil (some use liquid soap) to slide the upper seal in.  The is tricky, so be patient.

11. Place the lower seal in the cap.  Place some RTV on the tips of the seal.  Do not put RTV on the part of the seal against the bearing.

11a. Reinstall the cap - tighten to specs.

12. Clean the surface of the oil pan and the bottom of the engine.  Use a flat blade razor at a VERY shallow angle.  You do not want to gouge the block or pan.

13. Get the Felpro gascket.  Blue, rubber type.  Cannot remember the part #.  It comes with dowel pins to help guide it into place.

14. Reinstall pan.

15. Reinstall pan bolts.

16. Reinstall skid plate.

17. Reinstall starter.

18. Lower truck.

19. Fill with oil.

 

20. Lather. Rince. Repeat.

 

Since you have not done this before, bugdet a good 4 to 6 hours.  Read up on it and get the gascket and RMS before you start.  For tools, you will need a socket set with metric and SAE sockets, a rubber mallet and a torque wrench.

 

I've done this 3 times, once on the MJ, once on a 91 XJ and just recently on my 84 CJ.

[MuddFoot]

redo list step one remove battery cables but everything else is perfect...its not as hard as people make it out to be. rockauto.com has the rear main and oil pan gasket cheap compared to az or advance i think i paid 3.50 for rear main and 13ish for oil pan gasket 

[87MJTIM]

redo list step one remove battery cables but everything else is perfect...its not as hard as people make it out to be. rockauto.com has the rear main and oil pan gasket cheap compared to az or advance i think i paid 3.50 for rear main and 13ish for oil pan gasket 

 

CORRECT!

 

My bad.

[sinkrun]

Lots of video on you tube also.

[MuddFoot]

its my first correction on this site. its not often i get to help on here like i do on cherokeetalk.com

[gogmorgo]

Also worth noting, all oil leaks tend to look like a rear main seal leak on a 4.0, because the motor is canted back a bit, and all oil runs down and back. Valve covers and the oil filter/adapter are very common leaks that often look like a RMS leak.

[87MJTIM]

To your original question: how much?

 

You could estimate at standard billing rates, approx  3 to 5 hrs.  Depending on billing rates in your area, assuming $100, you're about $400 in labor plus parts.

 

Parts will be marked up, so guess around $500 total.

 

If you invest your time, you're only in for the parts.  That would be under $50 in parts: RMS, gascket, and oil.

 

The confidence in knowing how to do your own maintenance: PRICELESS.

[Pete M]

x2 check the valve cover first.

 

buy 2 seals.  just in case you mess one up.  then you don't have to run to a store mid-project.

 

also, let the RTV fully cure before firing up the engine.  learned that one the hard way. :(

 

 

If you pay a pro, don't let them convince you that the trans has to be pulled.  If they say that, go somewhere else!

[cruiser54]

I wrote this up years ago for cases like this:

 

 

 

 

I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.

 

Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking. 

 

 Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it? 

 

  A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.

 

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.

 

 First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

 

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first. 

 

Revised 02-26-2013

[dj5]

thanks everyone. I got a buddy who is a mechanic who said he would do it for $250 plus parts ($14). he said he has to remove the tranny, I told him from what people were saying it didn't seem that way but he wants to make sure it has a good seal.
maybe one day (hopefully not) when my xj rms goes out I can do that seal myself   :wrench: and save $235

it is definitely the rms tho, has brand new valve cover gasket and I can see it leaking straight from it, it just blows my mind because the PO just rebuilt and installed this engine and he even left the old one in the bed.

if he went through the trouble of replacing the engine, you would think that seal should be good :grrrr:

but anyways hopefully it should be done when he gets a chance to get to it in a day or so and hopefully all is good, will update.

 

on to the next problem of why my temp  gauge reads 155 right at start up when cold even after replacing radiator and temperature sending unit and still can't get my electric fan to turn on (it does when hotwired) even with a new relay and my tach idles under 0 still after 2nd cluster (temp issue was same on both clusters)  :oops:

[87MJTIM]

$250 plus parts of $14 isn't a bad price.

 

However, I don't believe he can do it that easily.  I do not think you can get to the RMS by pulling the trans.  The seals are set inside grooves/channels that are only accessible from under the oil pan.  So, the oil pan NEEDS to come off.

 

As I detailed above, you do not need to remove the trans.  Like Pete said, if someone tells you that you have to remove the trans, you need a new mechanic.

 

Go get a Haynes or Chiltons manual.  Read through about changing the RMS.  No where in the steps does it say to remove the trans.

[ParadiseMJ]

Just so you know...the BOOK...that mechanics work from to estimate hours and labor cost says as much as 6 hours labor.  So they charge 6 hours.  Which is why I started doing my own work on my Jeeps.  They wanted $500 labor to install a $14 part. 

 

Some vehicles require removal of the tranny...not this one. So, not to diss your buddy, but he's wrong, I've replaced 4 of these things on 4 different Jeeps and removing the tranny will not "give it a better seal"

 

DO NOT REMOVE THE TRANNY

[cruiser54]

$250 plus parts of $14 isn't a bad price.

 

However, I don't believe he can do it that easily.  I do not think you can get to the RMS by pulling the trans.  The seals are set inside grooves/channels that are only accessible from under the oil pan.  So, the oil pan NEEDS to come off.

 

As I detailed above, you do not need to remove the trans.  Like Pete said, if someone tells you that you have to remove the trans, you need a new mechanic.

 

Go get a Haynes or Chiltons manual.  Read through about changing the RMS.  No where in the steps does it say to remove the trans.

I agree.

[Jeep Driver]

I'll chime in with others........>>>DO NOT REMOVE THE TRANSMISSION>

 

The 4cyl are the only one that have a one piece seal behind the fly wheel and require trans removal.

 

 

Find a new buddy.

[cruiser54]

There's a reason I wrote this:

 

 

 

 

I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.

 

Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking. 

 

 Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it? 

 

  A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.

 

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.

 

 First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

 

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first. 

 

Revised 02-26-2013

[Pete M]

and you don't have to pull the trans! if I can do it, anyone can.

[MuddFoot]

I'll chime in with others........>>>DO NOT REMOVE THE TRANSMISSION>

 

The 4cyl are the only one that have a one piece seal behind the fly wheel and require trans removal.

 

 

Find a new buddy.

I  have changed 100s of these alot of them didn't need it they needed the oil filter o rings changed and the valve cover.... with the dealers computer says the tranny does not need to be removed and we only charged 3hrs shop time and oil lube and filter. if he waste his time pulling the tranny hes a dumba$$. you need some jeeper friends

[Eagle]

$250 plus parts of $14 isn't a bad price.

 

However, I don't believe he can do it that easily.  I do not think you can get to the RMS by pulling the trans.  The seals are set inside grooves/channels that are only accessible from under the oil pan.  So, the oil pan NEEDS to come off.

 

As I detailed above, you do not need to remove the trans.  Like Pete said, if someone tells you that you have to remove the trans, you need a new mechanic.

 

Go get a Haynes or Chiltons manual.  Read through about changing the RMS.  No where in the steps does it say to remove the trans.

^^^ Truth.

 

The RMS for the 2.5L 4-cylinder requires pulling the transmission. The 4.0L 6-cylinder does NOT require pulling the transmission, and doing so will not get him access to the seal. You have to drop the oil pan and remove the rear main bearing cap, and you can't do that just by removing the transmission.

 

I understand that this guy is your friend and he thinks he's doing you a favor, but ... he's not. He obviously doesn't know jack about Comanches, and he's probably going to mess something up dropping the transmission unnecessarily. That means it's going to take him two or three times as long to do the job as he thinks, and on top of that $14 seal you'll still need to buy a new pan gasket. (Hint -- get the '95+ one-piece pan gasket -- it works MUCH better.)

 

Either do it yourself, or take it to a shop that knows how to do it.

[sinkrun]

I just did one last week has nothing to do with the transmission. Hers some videos (not Mine)

 

 

 

[87MJTIM]

DJ5,

 

PLEASE take all of the comment as helpful suggestions and not criticisms.  Everyone on CC want to help you.

 

(As I stated previously, I am not a mechanic by trade.  Most of my education has come from the experts on CC and other Jeep forums. [Youtube has helped, also] .)

 

You do not need to drop the tanny.  Your friend may be knowledgable with other engines, but, apparently not with the Jeep inline 6.  (Base on your signature, you have 1) 4.2 and 2) 4.0 engines.  For the oil pan and RMS, the gaskets have not changed in over 20 yrs.)

 

If you are not comfortable taking on this project, find a REPUTABLE mechanic to do the work.

 

Just don't let someone tell you that you need to drop the tranny to change the RMS.  For the Jeep inline 6, this is a usless step.

[Steve Gregory]

$250 plus parts of $14 isn't a bad price.

 

However, I don't believe he can do it that easily.  I do not think you can get to the RMS by pulling the trans.  The seals are set inside grooves/channels that are only accessible from under the oil pan.  So, the oil pan NEEDS to come off.

 

As I detailed above, you do not need to remove the trans.  Like Pete said, if someone tells you that you have to remove the trans, you need a new mechanic.

 

Go get a Haynes or Chiltons manual.  Read through about changing the RMS.  No where in the steps does it say to remove the trans.

If you are getting a book, get Haynes.

[dj5]

I appreciate the input trust me I know your all here to help that's why I'm here :thumbsup:

I am going to send him a link to this page and let him see all the comments

 

Thanks guys

[MuddFoot]

just drive over here and ill change it. I'm in florida i take cash and beer. 

[87MJTIM]

just drive over here and ill change it. I'm in florida i take cash and beer. 

 

Hopefully, after you've finished the job. :yes: