Rear main seal clarification

[OldBlue2002]

I need to replace my rear main seal housing and have gotten through the step of removing the old one. Pictured below is the old housing gasket that has some residual oil on it, and I’m not 100% sure whether that gasket was failing or if the oil got one it during removal. The gasket  does look damaged on the inner perimeter. 

 

I have read many threads on the rear seal replacement and am skeptical on two things.

1) The new main seal needs to sit on a new section of the crankshaft, especially if a groove has developed. Should I be able to few this groove running my fingers along it? Can it be seen in the picture below? It feels smooth/unworn.

2) RealOem shows a shim sitting behind the seal, and I’m guessing this is to offset the seal placement on the crankshaft. My original seal did not have a shim and was sitting flush with the backside of the housing. Do I need to press the new seal deeper into the housing so it sits on a new portion of the crankshaft? 
Thanks in advance.

 

Scott

[Son of Marty]

Well if you clean off the end of the crank and don,t feel the grove set  the seal back where it was, if you need to set it further out you'll need a shim to make sure the seal sits flat

 

 

 

[Guest_anonymous]

the only way to be sure the seal is seated square is to press it fully into the housing. there is no way to press it further in than the old seal. you will need the shim to offset the new seal to sit in a different position. might as well just do it now if you question it than speculate for $13.

Edited June 25, 2020 by Guest_anonymous

[TobyB]

too late this time, but next time, clean it before you take it apart.

 

A $15 gallon of mineral spirits from Blowes and a $49c sprayer will rinse that all nice and clean

before you take it all apart.   If you buy a package of Puppy Pads from the PetStupid, a couple of

those turn the liquid mess into a solid. 

 

Me, I'd stuff another seal into the holder, a little RTV, bolt it up, all good.

 

t

 

[Hans]

Whats all that wrinkled material in teh straight on photo?

I've used the shim a few times - seems like cheap insurance.

[Mark92131]

9 hours ago, Hans said:

Whats all that wrinkled material in teh straight on photo?

 

Excess RTV on the oil pan gasket?

 

Mark92131

[OldBlue2002]

10 hours ago, Hans said:

Whats all that wrinkled material in teh straight on photo?

I've used the shim a few times - seems like cheap insurance.

At first glance, I thought it may be damaged gasket, but it just scrapes off and reveals the gasket is still intact on the inner diameter. I don’t see the substance anywhere else on the gasket except the interior, so maybe it is just an ancient byproduct of the oil over the years. 
I plan on using a new gasket and this sealer. Hopefully someone has heard of it before?

 

I understand the theory of using the shim, but don’t see how offsetting the seal by 1.5mm will make or break a good mating surface...especially if there isn’t a noticeable groove on the crank. I’m also not an engineer, so maybe I just pay the $15.
 

Edited June 27, 2020 by OldBlue2002

[coloincaalpine RIP 2021]

+1 Gasgacinch.  Been using it for 50 years.

[Son of Marty]

I for one almost never use any gasket sealer where the factory didn't use it, in the case of the rear seal the factory uses a small dab of what now is rtv where the seal holder, block and oil pan come together. I will use a dab if I find a sealing surface with a scratch across the gasket. 

[Hans]

5 hours ago, OldBlue2002 said:

At first glance, I thought it may be damaged gasket, but it just scrapes off and reveals the gasket is still intact on the inner diameter. I don’t see the substance anywhere else on the gasket except the interior, so maybe it is just an ancient byproduct of the oil over the years. 
I plan on using a new gasket and this sealer. Hopefully someone has heard of it before?

 

I understand the theory of using the shim, but don’t see how offsetting the seal by 1.5mm will make or break a good mating surface...especially if there isn’t a noticeable groove on the crank. I’m also not an engineer, so maybe I just pay the $15.
 

I meant the wrinkly bits between the pan and the block/seal bracket. Pic #2.

What exactly is the young lady doing with the gasket sealer?

[Hans]

The fact that BMW made such a shim suggests to me that wear can be an issue. Maybe at higher mileage,  i don't know. Cheap insurance. Question is, is there one for the front, and if not, why not?

[Guest_anonymous]

4 hours ago, Hans said:

The fact that BMW made such a shim suggests to me that wear can be an issue. Maybe at higher mileage,  i don't know. Cheap insurance. Question is, is there one for the front, and if not, why not?

I have not seen as part number for the front. Perhaps due to the clearance of the crank gear. Some people have used a quick sleeve.

[coloincaalpine RIP 2021]

Hans,

    She's been around since the beginning, old school advertising I guess, can't do that today,some feminist will raise hell and get it removed. You used to be able to see the hot rod between her legs and she had a pan gasket in her hand.

[Hans]

7 hours ago, coloincaalpine said:

"You used to be able to see the hot rod between her legs and she had a pan gasket in her hand."

 

I see.

7 hours ago, coloincaalpine said: