Wondering if anyone can tell me what I need to do to drill a pilot bushing

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Bigblockbryan1982

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Okay so I have a mopar 400 and I plan on using a mag drill to drill the whole for a bronze bushing I really don't want to cut the shaft go the needle bearing route it was a automatic 400 out of a motor home it seems I saw a diagram but I can't seem to find it the cranks still in the motor I don't really wanna pull the crank since the engine only has about 50,000 miles this is going in a truck I aquired
 
You seem to start every post with the word OKAY.

I remember you from Moparts.
You don't need a bushing. The roller bearing will work. No need to cut the input shaft either, it fits into the hole.
 
Kern Dog said:
You seem to start every post with the word OKAY.

I remember you from Moparts.
You don't need a bushing. The roller bearing will work. No need to cut the input shaft either, it fits into the hole.
Click to expand...
But I don't want a roller bearing when those things let go they can eat a input shaft saw it happen
 
Well, when I drilled mine out the input shaft had already been hacked on a little to fit in an auto hole.
So I used a bearing.
Car won't see that many miles and Brewer's sells a quality one.
I used a piece of angle iron across the flywheel with an appropriate size piece of pipe welded to it for a guide.
Someone said the cast cranks can be porous and can seep.
I coated the inside of the hole and the shaft doesn't touch the crank hole, in theory.
 
Bigblockbryan1982 said:
Okay so I have a mopar 400 and I plan on using a mag drill to drill the whole for a bronze bushing I really don't want to cut the shaft go the needle bearing route it was a automatic 400 out of a motor home it seems I saw a diagram but I can't seem to find it the cranks still in the motor I don't really wanna pull the crank since the engine only has about 50,000 miles this is going in a truck I aquired
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You can make your own bushing and put it in the torque converter register.

Otherwise, you need a lathe, a good steady rest and dial indicator. Then indicate both ends of the crank in, and use a boring bar and finish the pilot bunching hole.

Much easier to make your own bushing as outlined above.
 
Well here’s my 2 cents , I have installed many a roller bearing , as long as you add a little extra grease when installing never seen one fail , throw out bearings on the other hand ....lots of them , good luck either or will work.
 
The fatigue failure on the shaft and input bearing, from your highly off center hole and bushing, will make a roller bearing failure seem quaint and charming.

Do it right or don't do it. Pull the crank and have a machine shop do it, if you can't bring yourself to use a bearing that's been the go to standard for twenty five years.
The mag drill idea sucks.
 
I tell you what sucks. Trying to do this job any other way but the right way. Take the crank out and take it to the shop. THey'll get it dead right like it needs to be.
 
Im pretty sure there is a bronze bushing style out there that replaces the roller bearing one. Goes in the torque converter register. You could hand drill the smaller pilot hole deeper to accommodate the end of the trans input shaft.
 
mod5v said:
Im pretty sure there is a bronze bushing style out there that replaces the roller bearing one. Goes in the torque converter register. You could hand drill the smaller pilot hole deeper to accommodate the end of the trans input shaft.
Click to expand...
I'm probably going to have a buddy whosva local machinest help drill it with the mag drill Saturday or we might just go other route and make a bu
mod5v said:
Im pretty sure there is a bronze bushing style out there that replaces the roller bearing one. Goes in the torque converter register. You could hand drill the smaller pilot hole deeper to accommodate the end of the trans input shaft.
Click to expand...
 
What do you have in the back of the crank already? Just a center?
upload_2019-6-27_8-15-15.png

Then you should probably pull the crank if you want to get it to stock bore and depth dimensions. Check the oil passage locations and make sure you don't go too deep or too big in diameter. You should probably check the crank thrust bearing for wear and end play anyway.

If by chance it's drilled for adequate depth like this '68 440 steel auto crank and not diameter you could just do a self made bushing in the converter register as YR indicates and not cut the input. I don't think they are being made these days. Then too, you may even be able to open up that first step to accept the stock bushing.

upload_2019-6-27_8-17-26.png


Just a center in the crank and using a converter register bearing or bushing, measure for .100"/.125" clearance and trim the input.

Any way you go, indicate the bell housing in.
 
Bigblockbryan1982 said:
I'm probably going to have a buddy whosva local machinest help drill it with the mag drill Saturday or we might just go other route and make a bu
Click to expand...

If he does help you do this with a mag drill, can you please post his info so we can, um, refer to him in the future?
 
SGBARRACUDA said:
Read my post #11 in this thread about drilling cast cranks.
383 440 swap. Same flywheel?
Click to expand...

That's exactly what I was talking about in post 4 here.
I'm glad you weighed in so I can ask you.
Is seems like the way you finally figured it out would be that a rear main seal leak would be in front of the fly wheel and not affect the clutch face.
While a seepage from the pilot hole would be aft of the flywheel on it's face.
Is that the case?
I had already done mine to a later engine and I coated the inside of the hole with varnish.
As stated, I don't think the transmission input shaft touches the hole and I'm also hoping that later 70s cranks were not as porous as the ones you had to deal with. (76 is mine IIRC)
The register bearing will keep it where it is supposed to be?
Hoping.
And the thought occurs to me, that if all cast cranks are that porous, they all would be unusable with a 4 spreed car regardless of what is done in this respect.
 
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adriver said:
That's exactly what I was talking about in post 4 here.
I'm glad you weighed in so I can ask you.
Is seems like the way you finally figured it out would be that a rear main seal leak would be in front of the fly wheel and not affect the clutch face.
While a seepage from the pilot hole would be aft of the flywheel on it's face.
Is that the case?
I had already done mine to a later engine and I coated the inside of the hole with varnish.
As stated, I don't think the transmission input shaft touches the hole and I'm also hoping that later 70s cranks were not as porous as the ones you had to deal with. (76 is mine IIRC)
The register bearing will keep it where it is supposed to be?
Hoping.
And the thought occurs to me, that if all cast cranks are that porous, they all would be unusable with a 4 spreed car regardless of what is done in this respect.[/QUOTE
This is the long winded post I posted April 29 2010.
Here is the link read post 14
Search Results for Query: rear main leaking thru crank | For A Bodies Only Mopar Forum
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Also the car I was working on was a Automatic. So I didn't need the hole for a manual input shaft.
 
SGBARRACUDA said:
Also the car I was working on was a Automatic. So I didn't need the hole for a manual input shaft.
Click to expand...

Thanks for the extra info.
The question remains in my mind for the engine experts about manual cars.
Did any manual cars have cast crank motors of any type?
Perhaps a 360 car or truck with a manual?
 
ALL 360s had cast cranks and, I believe, ALL 400s. Both could be had with manual transmissions in cars or trucks.

As for drilling the crank. I've done it. Possibly the worst beating my hands and wrists have ever taken. It is IMPOSSIBLE to get a straight hole and I had a reamer to finish the job off. Next crank for that motor went to a general machine shop as the engine shops were not equipped for this task...I think it cost me $25...
 
Jim Lusk said:
ALL 360s had cast cranks and, I believe, ALL 400s. Both could be had with manual transmissions in cars or trucks.

As for drilling the crank. I've done it. Possibly the worst beating my hands and wrists have ever taken. It is IMPOSSIBLE to get a straight hole and I had a reamer to finish the job off. Next crank for that motor went to a general machine shop as the engine shops were not equipped for this task...I think it cost me $25...
Click to expand...

Negative on the 400. I have torn down a 77 400 that was an all original factory maltese cross engine, and it also had the factory playing card markings on it as well Crank was steel and was .001" under. It did come out of a manual transmission truck, though.
 
reading through this it seems if you have a machinist buddy then getting him to make a bush (or turn down a stock bush) to fit both your crank and the trans input shaft is by far the easiest, cheapest and best option. it'd be a no brainer for me :thumbsup:
neil.
 
mygasser said:
reading through this it seems if you have a machinist buddy then getting him to make a bush (or turn down a stock bush) to fit both your crank and the trans input shaft is by far the easiest, cheapest and best option. it'd be a no brainer for me :thumbsup:

yea we might just make our own bushing to be honest the problem is the hole for the converter from the automatic is too big and half as deep as it should be I'm not totally outlawing the idea of doing a needle bearing I just hate the idea of hacking 1/2 inch off the input shaft
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Well it's not like your doing something to your 4 speed that isn't reversible. Replace 4th gear and it's back to original. ( if you do cut the input shaft.)
 
RustyRatRod said:
Negative on the 400. I have torn down a 77 400 that was an all original factory maltese cross engine, and it also had the factory playing card markings on it as well Crank was steel and was .001" under. It did come out of a manual transmission truck, though.
Click to expand...
Rob is correct. 400's from the factory with manual transmissions came with forged steel crankshafts.
 
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