Rear Main Seal Leak

[The Baron]

I was reading the GM 6.2 Diesel service manual and they state a method of fixing the rear main seal without having to remove the crankshaft. I was wondering if anyone has tried this and had success? [h=2][/h][h=2][/h]

 

[richingalveston]

should be some threads here on it. yes it can be done but I think you have to slide tranny back to pull flex plate and torque converter. I think you just have to loosen the cap bolts in the back to slide the new one in. I have not done it but have read threads here about it. I was going to be doing it soon but I opted for new motor.


Good luck
Rich

 

[cpf240]

Is your CDR valve functioning correctly? If not, over-pressure in the crankcase can lead to rear main seal leaks. Secondly, are you sure it is the seal that is leaking? Often a small fuel leak up in the intake valley can run out the drain hole at the bottom of the bell housing and look like an oil leak.

 

[The Baron]

I'm relatively certain that it is an oil leak, however I'll go check. Are there any other leaks, besides the pan and main seal, that may cause drips at the bell housing?

 

[cucvrus]

If you have a rope seal for the rear main seal it needs changed. Everyone that I seen leak and changed was the rope seal. I out lined changing the rear main seal in my Terminus M1009 thread. It is really not all that bad of a job. But it is very dirty and you will get oil drops on your shirt. I did have to loosen all of the main bearing caps on the Terminus M1009. But I do NOT always have to do it. I have been changing every rear main seal on every truck going forward. It seems to be that time in all the CUCV'S lives. Cost in parts and materials oil & filter is about $100. Good Luck.

 

[cpf240]

I'm relatively certain that it is an oil leak, however I'll go check. Are there any other leaks, besides the pan and main seal, that may cause drips at the bell housing?

Fuel running down the drain from the intake valley can look like an oil leak by the time it comes out at the bottom of the bellhousing, as it washes dirt, etc down with it.

 

[Tow4]

Oil leaks are the only thing keeping a mid-80's Chevrolet pickup or Blazer from rusting to the ground.

 

[dougco1]

Fuel running down the drain from the intake valley can look like an oil leak by the time it comes out at the bottom of the bellhousing, as it washes dirt, etc down with it.

I would have bet the farm on an oil leak in mine but like cpf240 says, mine was leaking fuel from a cracked fuel line nut at the injector pump. Very common problem with old lines and all that vibration.

 

[The Baron]

Looks like I'll have to wait until Monday to asses the damage. If it really was a fuel leak that would make my year.

 

[richingalveston]

if you have a fuel leak, you would have hard starts and long cranking times. if your truck starts right up, it is an oil leak

 

[dougco1]

if you have a fuel leak, you would have hard starts and long cranking times. if your truck starts right up, it is an oil leak

Not all true.
Mine apparently only leaked while running and under pressure. I never had hard starting issues, that's why when I saw the drips in the driveway I assumed it was oil.

 

[The Baron]

The intake valley is as dry as can be. I guess it must be the rear main seal. Is there a way to tell if a cdr valve is bad or a certain amount of miles you have to change it by?