W123 Rear Main Seal...........How much $? - PeachParts Mercedes-Benz Forum

BigRed0803 · #1 06-18-2011, 10:39 PM

My ole 300D has developed a solid oil leak, leaking about the size of a softball within minutes of turning the car off. I got under it today and saw it dripping directly from where motor and trans connect. The rest of my engine is spotless so I know it is not the valve cover gasket or oil filter housing, it is definitely the rear main. Does anyone know what the going rate is for that repair, I was going to check with my indy on Monday but was just wanting to get an idea. What is the book time on that repair, I know it is very time consuming. Anyone that has any info on the time of the repair or price let me know so I can get an idea what I am up against. Thanks

leathermang · #2 06-18-2011, 10:44 PM

While it is likely the rear main seal....
it could also be a leak at the rear of the engine where the oil passage to the oil squirters is sealed with a big ball bearing.... sorta a push in seal... it would show up the same as between the engine and trans bell housing....

whunter · #3 06-19-2011, 12:40 AM

I would clean the area around the oil filter housing = where it mounts to the engine block.

This gasket is a common failure = engine air flow sprays leaking oil into the torque converter area, making it look like a failed rear main seal when it is NOT.

Gasket To Oil Filter Housing
MB# 616 184 07 80

Fastlane: Oil Filter Stand Gasket
http://catalog.peachparts.com/item.wws?sku=W0133-1641230

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leathermang · #4 06-19-2011, 07:21 AM

Lets all get on our knees and pray it is not the rear seal .....

Would be interesting for people to share how much it has cost them to fix it in different ways... ( DIY, dealership,MB indy )....

Diesel911 · #5 06-19-2011, 08:29 AM

People often ask this sort of question. But, the cost of a repair is going to depend on where you live.

It is best to get on the Phone and call some places in you local area see what they charge.

I would also make sure that my Crankcase Breather system is working OK. If it is restricted the Crankcase Pressure will try to find some other way to get out of the Engine.

It also would not hurt to make sure the upper Oil Pan Bolts are tight.

leathermang · #6 06-19-2011, 08:35 AM

Well, they could say it costs about $____ to fix it a certain way and I am in the _____ area...

BigRed0803 · #7 06-19-2011, 09:11 AM

Yeah guys, I know your somewhat skeptical about it being the Rear Main but trust me I can gaurantee you it isn't the oil filter housing or any other of the common leak areas on this engine, you could eat off this engine, there is no oil residue at any of the common areas. I know the price of this job depends on where you are from, but I am simply wanting to get a ballpark idea. If nobody knows the pricing the book time on this job shouldn't change depending on where you live so if someone possibly knows the book time on replacing the rear main seal I could use that to get an idea of what Im looking at price wise.

leathermang · #8 06-19-2011, 09:42 AM

If you know it is not the other gaskets mentioned to look at....
Why are you guys skeptical that it is the rear main gasket ?
That is one of the hardest working gaskets in the engine... like James Brown... the suggestion I made... if it is not the rear main remains a good one... since it is also covered by the trans bellhousing...

But I am betting on the rear main because while I know about the oil passage due to reading the FSM... I have never heard of anyone having a leak there..

It is a huge job to replace the rear main seal... so brace yourself for sticker shock unless you are willing to do it yourself...
Almost entirely LABOR...

Why don't you just drive to a few places close by and get estimates ?
Then come back to here for comments on the reasonableness of them...

junqueyardjim · #9 06-19-2011, 10:42 AM

I think to replace the whole rear seal the engine has to come out and the crank removed. It is a "rope" type of a seal and the lower half can be replaced by dropping the upper pan, which is a major job. Whether or not the upper half can be pulled through with out dis-assembly of the crank is a guess. I know on old GM engines like the 292 six cylinder which was used for years in trucks, it could be pulled through using a flexible "Chinese finger" tool.

leathermang · #10 06-19-2011, 10:58 AM

The first time I used one of those finger tools I thought it was magic... also... there were screws which could go into one side and then you turn the crank as you gently pull it out..
But alas , I am pretty sure from past threads that there is a pin in the top section of this one...and the crank does need to be lowered to remove the top portion..
I hope I am wrong... but....

kerry · #11 06-19-2011, 11:29 AM

Army had a thread with pictures of the seal. The top part cannot be pulled thru, there is a pin and the crank has to be dropped. Maybe it can be done in place with the engine raised up and main bearings removed, but it's probably just as easy to pull the engine and tranny together and do it outside the vehicle. I think Leathermangs hypothesis of a leaking oil gallery plug cannot be excluded since under the engine, the oil would appear in the same place as oil leaking from a bad rear main seal. That plug should certainly be inspected when replacing the rear main seal. My failing memory tells me that many years ago a forum member had that oil gallery plug fail. I'm thinking the job would be in the $1200 range.

BigRed0803 · #12 06-19-2011, 01:07 PM

I will call my indy tomorrow, I was just trying to get an idea of price or time on the job.

junqueyardjim · #13 06-19-2011, 01:08 PM

You know, I wonder if it was leaking past that steel ball in the back of the block, I am going to look closely at the 617 I have on the floor and see if I think a wad of the stick type JB weld would stop the leak. Shouldn't hurt anything and if it has to come out, it could be drilled out. Why would you ever want it out. All it does it keep the oil in the system.

leathermang · #14 06-19-2011, 01:10 PM

Quote:

Originally Posted by junqueyardjim

You know, I wonder if it was leaking past that steel ball in the back of the block, I am going to look closely at the 617 I have on the floor and see if I think a wad of the stick type JB weld would stop the leak. Shouldn't hurt anything and if it has to come out, it could be drilled out. Why would you ever want it out. All it does it keep the oil in the system.

LOL... If you have an engine out on the floor ... open up that sealed ball thing and clean out that oil passage... that is the time , place , and reason it was designed that way... it is the only way to access it....

Stretch · #15 06-19-2011, 01:19 PM

Here's a link for the OM617 rear crankshaft seal thread mentioned by kerry.

Fitting rear crankshaft seal on an OM617

If it is a leaking ball bearing at the end of one of the oil galleries then that probably will be an engine out job too as you need to shove a long rod down the length of the engine to remove them - as my engine is still out of the car I can't check to see if you could get away with removing the radiator (plus any air conditioning stuff if you have it) and gearbox if you wanted to do that... but to be honest I think it would be easier to "just" remove the engine and gearbox in one go. I can however have a look at the end of the engine in the next few days to see if you can see the ball bearings in the block with the transmission adapter in place - I've got a nasty feeling that needs to come off too - which also means flywheel removal...

I'll check.

So before you commit yourself to either a ball bearing or a rear crankshaft seal replace - read what whunter said!