cast 440 crank

[Cuda7d74]

i got the crank drilled for manual tranmission
i have a oil leak now
iknow where it is
has anybody repair this problem
Cuda7d74

 

[Cazbah362]

Cuda - your a little vague, but would assume its in the rear seal. Just a thought, more vacuum?

 

[moparleo]

First welcome to the site. Second as Casbah362 said, we need more details. You say you know where it is leaking, but you don't tell us.

 

[Cuda7d74]

It was a automatic transmission crank
I had to get it drilled for the manual transmission input shaft
Cast iron cranks are pourous
So at the back of the drilled hole there is a pin hole.
I ran the electric drill to run the oil pump to make pressure,also heated the oil up to thin oil out
Iam new at this forum sorry
Cuda7d74

 

[moparleo]

So has the engine been run yet ? Is it still on the stand? You say you ran a drill to prime the engine and is that when you saw oil coming out of the pilot hole in the back of the crank ? If it is leaking for sure because of porosity in the crank casting, that crank has to be junk. Solution, get a new crank. Done.

 

[Cuda7d74]

thats fine
engine has been balance
so it has to come apart to get balance with a difference crank.
so i put in a frost plug in,making a new pilot bushing accept it going to be a blank bushing,then cut the end of the transmission input shaft because you dont use all of it.what do you think?

 

[moparleo]

NO! NO! NO! Think about it for a minute. How big is the void in the back of the crank ? Without x-raying the crankshaft, you don't know not only how large and what shape the void is in the crank or how many other voids could be in the rest of the crank. If the crank fails, how much damage parts and $$ wise will happen. You are fortunate to get the warning. Please take advantage of this warning. The people that balanced your crankshaft will have a record of the weights used during the balance and should have no problem balancing a new crank shaft to the same specs. The rest of the parts should not need rebalancing.

 

[Cuda7d74]

Thank for the warning
It's good to know
Maybe that I have a vibration
Thank again
This form is new to me and still don't know how to use it
Thanks
cuda7d74

 

[Cuda7d74]

You have your normal hole for the bushing,which is 1 " deep, then a 13/16 hole for the end of input shaft of transmission the pin hole is in the back of the hole.
Cuda7d74

 

[Cuda7d74]

Do you know of problem with cast crane?
The crane was check out balance
The crank was drill
Bushing hole is 1" deep
Then a13/16" hole for the input shaft of the transmission
The pin hole is in the back of the hole,not the side
Cuda7d74

 

[moper]

If there is oil coming out the hole when there's oil pressure in the system, the crank is junk. There should be no connection between the oil passage through the #5 main and the pilot bushing bore. I think the shop drilled it too deep. If you want I can measure a factory drilled hole tomorrow for you. Regardless, if you have oil flowing out the back - the crank is junk. Any repair would be superficial and working against the crank flexing and moving (normal), and the pressurized oil. It would will only slow down the flow, and if that was an internal crack, it will spread a lot faster now. Replcae the crank. It will be more $$ to fix it later than to get another crank and rebalance. The balancing won't be much either because it's just the crank work that needs to be done.

 

[js29]

i am more bodyman than mechanic but i am with leo, 100% cheaper to do it now than later.

 

[Daves69]

You have your normal hole for the bushing,which is 1 " deep, then a 13/16 hole for the end of input shaft of transmission the pin hole is in the back of the hole.
Cuda7d74

Are you saying the hole is 2.465" deep from the end of the crank?

 

[RzeroB]

Hi. English is not your first language is it? Curious as to where in the world you are?

Anyway, your crankshaft issue doesn't make much sense to me. So let me see if I have this right. Crank was drilled to specs for a pilot bushing hole. There appears to be a "pinhole" at the bottom of the pilot hole. Pressurizing the oiling system (with a drill) results in oil leaking from the pilot hole pinhole. Sorry, but it doesn't make any sense to me. There shouldn't be anything forward of the pilot hole other than solid steel. The oil passage from the #5 main bearing angles forward to the #8 rod journal and it is well forward of the pilot hole. Just look at the pic, you can see how far away the oil feed is from the where the pilot hole is.



Just to clarify, cast cranks are not "porous" because they are cast vs being forged. For some reason, there seems to be a perception that cast cranks are made of cast-iron while forged cranks are made of steel - which is wrong as they are both made of the same material - high strength steel.

How oil would be coming out of this pinhole in the pilot hole just doesn't make any sense to me unless there is something seriously wrong with your crank. By "wrong, I mean either your crank has a serious casting flaw or your pilot hole was drilled way beyond specs to the point where it contacted the feed to the #8 rod journal. If oil is in deed coming out of the pinhole in the pilot hole, your crank has serious issues and I would pull it out and have it carefully inspected by a competent machinist.