Rear Main seal Leak EEKKKK :( How much for a mechanic to fix it?

[acenjason]

I seem to have a leaking rear main on the 440 dodge in my 75 Brave D21. Has anyone had this fixed? How much did it cost, or how many hours for the mechanic? I read the part is actually not that expensive. Is that true? Has anyone tried the oil additive that is supposed to stop leaks? Any input would be great:) Thanks in advance:)

[Oz]

Forget the additive.  A)  You really don't want that stuff in your system because it's not like a thinking being.  It doesn't all just go to the seal.  It goes everywhere else too.  B)  It doesn't work, unless maybe you only have a very small leak, and it doesn't last very long anyway.  Remember, these are RVs, not cars, and are constantly subject to heavy load. We've had enough people try it and regret it, including me. 


There's a rope seal and a rubber seal.  Actually, it's not hard to replace it and the cost for the seals is negligent, but you're going to get into at least 2 - 3 hrs of labor at the mechanic.

How much does it cost to have a mechanic fix it?  That will vary from mechanic to mechanic.  The only way to accurately know is to call your mechanic (and others able to do it) and find out for yourself, in your area.

[acenjason]

Thanks for the info:)

[cosmic]

I heard that sometimes you can end up worse trying to change it then it was prior. I have opted to leave mine drip a little. 9 years and counting. lol. if you do pay someone to do it. let us know how you make out.
it is done through the oil pan so, the good thing is the nothing need s to be separated.

[TerryH]

Acenjason
This is in case you are not familiar with or not too experienced with spinning wrenches, particularly on an RV - if you are, please ignore:
Changing a rear main seal is as Dave said not that hard. Actually it is a fairly easy operation and a good one to do if you are breaking into mechanical repairs on an RV, where other than this, you may find  access very daunting. 
Drain the oil - oil change is good, and you will locate the filter. Drop the pan, clean the old gasket off, check for dimpling on the top of the pan where it meets the block and flatten if required - part of reinstallation.
Now you get to actually see rather than look at a picture of the con rods, underside of the pistons, crank and lobes, bearing caps, and the oil pump.
Remove the rear bearing cap (very carefully, you don't want to damage the bearing)
Follow the instructions that came with your new seal for re and re very closely.
Reinstalling the cap requires a torque wrench, which is a good investment.
Installing the new pan gasket may be somewhat tricky so ask for advice if you are not sure.
New oil and filter, start it up and check for leaks.

Not quite this simple, but..........

Nice thing about a rear main is that it is very unlikely that it will suggest other things to do at the same time - follow Frederic's post re his head gasket to see what I mean.
Further to Dave's - additives - no. If if they worked, they would only postpone a problem.

Of course, safety first. If you use jacks don't rely on them. Adequate jack stands.

[Stripe]

I am going to second his jackstand comment.  When doing my front springs, I used the level jacks to bring up my front end, but I made sure I had adequate size rated jackstands up under the RV as well. The level jacks are on a swivel and do not stand fast when extended..

[MotorPro]

Terry's Instrutions are very good except that on a 440 vs a 454 you do not remove the rear main just the seal retainer.

[TerryH]

Thanks for clarifying MotorPro. I didn't know that.

[acenjason]

Thanks for all the good info......i thought the tranny had to come out on the 440. I ain't a bad wrench ( i just installed a new edellbrock 1411 two weeks ago)I just don't have a tranny jack or jack stands that will hold half of a 8500 pound rig. It is intermittent. I just drove 50 miles through the high rockies and can't tell a change in the dip. I saw small spots, but a week ago she leaked a quart in the same distance and got the state park camp ground on my case cause she was leaving foot wide spots at the gate and dump station. If it is just inside the oil pan maybe I could do it myself........more input invited:)

[TerryH]

The basic simplicity is that it is all inside of the oil pan. Other than the seal and retainer, nothing else to remove.
Tranny jack - for this - not required. Adequate jack stands or a very, very good support system is.
Again, consider buying a good torque wrench if you don't have one. Brakes, wheels, manifolds etc. require and work better if torqued correctly.
Dave has posted a very good tutorial on torque wrenches in more than one topic here. Especially informative if you are using the wrench at the upper end or beyond its' calibrations.
I don't have the links at hand, but I suspect he does.

[TerryH]

I saw small spots, but a week ago she leaked a quart in the same distance and got the state park camp ground on my case cause she was leaving foot wide spots at the gate and dump station.

Unfortunately it won't get better by itself - only worse. Foot wide spots at a dump station - not something you want to ignore or put off. With loss of oil you lose lubrication and heat dissipation between moving parts resulting in possible loss of your engine.
Very pricey.

[acenjason]

Thank you for the info:)