350 rear main seal

[djw&cjw71lemans]

Dealing with a difficult tranny leak. The shop is going to take it out and reseal everything. They said they would do the rear main seal also IF it's a one piece seal. Apparently GM made a two piece seal and then changed to a one piece. The two piece are very problematic and difficult to replace etc. so I'm trying to find out if my 1971 lemans sport 350 has the one piece rear main seal or the two piece. Does anyone know what it has or when the change to one piece took place? Thanks.

 

[Zimgxp]

'71 Should be a two piece seal.

 

[92 Sunbird LE]

Can be done with the motor in the car but oil pan has to come off and the rear main cap also.( they make "fishing" tool to get the top half out)

If it aint leakin , dont mess with it............IMO


Doug in P.R.

 

[melsg5]

sounds like you are confusing Chevy 350 and Pontiac 350. The Chevy 350 over the years switched from a 2 piece to a 1 piece. Pontiac never did. Hope your shop knows what they are doing.

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[djw&cjw71lemans]

Thanks. So do you mean the Pontiac 350 was always a 2 piece? I was hoping it was 1.

 

[92 Sunbird LE]

Correct.............it can be changed at another time with the trans in the car if it starts to leak.

I would only trust that job to an old school mechanic.....not many nowdays have ever changed one.

Doug in P.R.

 

[djw&cjw71lemans]

Thanks. What I may not have made clear is I am pretty sure it is leaking as well as the transmission. There is definitely oil coming from that area. We will know more when the tranny is out this week getting resealed I hope.

 

[implden]

'71 Should be a two piece seal.

DO you know what year Pontiac stopped using the Fiber/Rope rear mail seal ?

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[melsg5]

Why do you think the factory stopped using them?
Rockauto lists them to 79, last year.
Aftermarket Pontiac vendors have viton seals.

 

[cammerjeff]

melsg5 is correct,

The factory used rope rear mains on all V8's thru the end of production of the 301's & 255's in 1981. If yours has a non rope seal it has previously been replaced with an after market seal. If yours has the rope seal I would suggest making the change to the aftermarket viton seals. The original rope seals contained asbestos that is not used in the modern replacement rope seals. The modern replacements do not seal as well as the original rope seals.