SMD rear main seal conversion

DanMD · Nov 4, 2014

Hello,

The engine out of my SMD is currently in the machine shop. I remember a member on here, maybe DSlater mentioning a service update to convert the felt rear main seal to a rubber lip seal. I was wondering if anybody would have any useful information I could pass on to the machinist to make this a successful upgrade. Is there a IH bulletin for this somewhere?

Thanks for any help,
Dan

sflem849 · Nov 6, 2014

I know I had bad luck putting the felt seal into the steel retainer.

I will wait to see if people that know the real answer tell you before I turn into a parrot.

D Slater · Nov 6, 2014

IH used to sell the change over package with instructions. They said to dull the sharp edges of the oil grove. Ones with the change that I notice just have the upper edge of the grove rounded off a little.
If you can find the seal (around a hundred bucks sometime ago) you need the cast or steel retainers and the different length bolts used to mount them. Also they used a different gasket between the retainers, the two small ones. Retainers will have a 271xxxr1 number on them, don't remember the whole number. May have one if you need, would need to look.
At one time IH started only furnishing replacement crankshafts like used in the later 400 and 450 engines without the oil return grove. They wanted most engines switched over to the new seal. But now its easier to get parts for the old type.

sflem849 · Nov 6, 2014

The 271XXXr1 retainer is the update for the MD/SMD/SMDTA and the standard for the 400/450?

D Slater · Nov 6, 2014

Part of the 400 came the rope or felt and I think sometime in 55 the 400 was changed to the rubber seals and crankshafts with no oil return grove. There was a engine # serial break. Could be wrong on the year without looking. All D-281 used the late seals.

DanMD · Nov 7, 2014

Do you know if there ever was a cast iron retainer for the felt seal? My IH salvage parts guy tells me he has in stock the aluminum ones, cast iron for felt seals and cast iron for the rubber seal. I have never heard of a cast iron retainer for felt.

Thanks,
Dan

D Slater · Nov 7, 2014

Only the die cast or aluminum ones for the felt seal that I know of. Top half of the die cast is the same as the gasoline engines. You can see the number on all the iron ones I see. If the numbers are 271792R1 and 271793R1 that's for the rubber seal.

SMD rear main seal conversion

DanMD

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sflem849

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D Slater

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sflem849

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D Slater

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DanMD

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D Slater

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