Keep or Remove Knurling on Crank?

[Chatt69chgr]

My 440 engine is currently at the machine shop.  I'am using a stock 69 forged crank with rear main knurling intact. 

Should I have the machinist remove the knurling or leave it?  I plan on using a new neoprene rear main seal.  Engine had about 95,000 on it when I tore it down.  Original rope seal was still in place.

[A383Wing]

I have never removed the knurling....and I run the rubber seals in all my cars

Never had any leaks

[Chatt69chgr]

Thats good to know.  I would think that after rubbing the rope seal for 95,000 miles that any rough edges on the knurling would have been worn pretty much smooth.  Now if it were a new crank with the knurling, then I can see that you would want to have it removed as it would probably be sharp.  But I want to hear what everyone's actual experiences are with respect to keeping or removing the knurling.  I'am sure that those Chrysler engineers had it put there for a reason and I am thinking that it did have to do with the rope seal.  Logic wants to tell me that with a rubber seal, you would want a smooth surface.  My crank's at the machinist right now and I still probably can have it removed if need be.

[Challenger340]

I have never removed the knurling....and I run the rubber seals in all my cars

Never had any leaks

Same here, at least not any leaks that were attributable to the knurling.

[firefighter3931]

The knurling on factory cranks is much less agressive than on some of the newer aftermarket pieces. Most OEM cranks that i've seen have been pretty smooth allthough there is some evidence of knurling present. 

That being said, if the crank has that many miles on it then i would polish it and leave it alone. 


Ron

[Chatt69chgr]

Thanks to Ron and all-----you have put my mind at ease.

[ITSA426]

Our local crankshaft shop told me he removes the knurling on mopar cranks because almost no one uses the rope seal anymore.  Smooth surface works better on neoprene seals.  He's done at least half a dozen for me and none have leaked.