225 Slant 6 crankshaft issues

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brandongjohnson

brandongjohnson

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Hello,

About 12 months back I picked up a 225 slant longblock from a 1968 Dart a few hours away from my house. I had it sitting in my garage, waiting for an opportunity to drop it into my truck. It was supposed to have been rebuilt recently and was basically ready for me to transfer accessories, etc over and install it. I assembled it on the stand, got everything together and ready to go. I pulled the engine off the stand to join the transmission (an a833) and install the clutch and was horrified to find this is what the end of the crankshaft looked like where the pilot bushing should go.

At this point I'll be doing a crankshaft replacement I assume. I'm not sure if the local machine shop route or buying another crank is the best bet here. From reading I'll need to track down a crank from a 1968-1976 225cid slant 6. I've found a replacement "Crankshaft kit" w/bearings from Mabbco. Dodge Chrysler 3.7 225 Crankshaft Crank Kit 1968-1976

I've read some less than stellar reviews of their entire longblocks, but wasn't sure if anyone here had used their crankshafts? I've never rebuilt the bottom end of a motor before and I don't posses most of the tools to do it, so the idea of the crank coming with matching rod and main bearings was pretty appealing. Any other suggestions on the right thing to do here? Should I just pull that crank and bring it to a machine shop? Does that look like something that they'd even be able to fix (maybe fill the crank and then re-drill the pilot bushing)?

IMG_0188-1.PNG
 
Im guessing its an unfinished automatic crank? Can you get a roller pilot bearing from NAPA and use it in the A/T convertor bore?
 
It's supposed to be a 1968 block (the block number is #2806830-2), so my understanding is from '68 and up that all the cranks were bored for the pilot bushing anyway? Not sure if that photo shows it super clearly, but the hole is almost off-center/ovalized or something. I suppose it could be a factory cast, it just looks way worse than that, and either way something that will prevent me from installing the pilot bushing properly (or at all).
 
I'm thinking that a magnum roller pilot will fit in the converter register in the crank.
 
Professor Fate said:
More Information for NATIONAL FC69907
Seven bucks. Mounts in the convertor register, avoids the pilot counterbore issue entirely.
Click to expand...
You hit the nail on the head.
I've used these a few times, and with great success.
To the O.P., use this bearing and forget about the ovalled out pilot bushing hole in the end of your crank.
I also think using the bearing is actually better than the factory bushing anyway.........
 
Yep what they said.
Clean up the counterbore that the roller bearing fits into with some sandpaper and you'll be good to roll.
The tip of the A833 input shaft will just extend into the cavity where the oilite bushing would normally be.

You may find that the bore in the crank may not be deep enough for the shaft to fit without bottoming out. (Preventing the transmission bolting surface to fit flush with the bell housing face.) If that happens the easiest fix is to cut up to 1/4" off the end of the input shaft and re-chamfering the tip.
 
Make sure the jacked up pilot hole is as deep as the old cranks pilot hole...or else you will have to hack about 1/2 inch off the input shaft to not bottom out in ththe crank

Register style roller pilot besring gets my vote too.
 
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I ordered up that roller bearing today from Napa, should hopefully have it by the end of the day or tomorrow. I'll see how it works; worst case if it still seems messed up I'll snap some more (clearer) pictures. Hopefully won't even be necessary- it would certainly be huge weight off my chest if I didn't have to worry about this and can move forward with installing it.
 
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