MN71W30

I watched a video with Joe Mondello insisting that the rear distributor oil plug be drilled .040.
I just bought a rebuilt never ran 455 shortblock and the plug hole is not drilled.
1. Do the original Olds big blocks have these holes?
2. Has anyone ever wore out an Olds dist gear?
3. Is it worth the trouble to replace mine with one drilled .040?

This 455 block is not drilled for a stick. When I saw I could buy a "self centering"? bearing at Mondello's to fit in the larger torque converter machined area at the back of the crank, I called them and the guy said they have never had a problem with them or even a call with issues. I hate to pull the crank and risk damage during the drilling process or me doing something stupid or having the machinist screw it up. But I swear I heard of troubles with these. I plan on drilling the back of the cast crank and not cutting off my muncie input shaft.
Is it worth the risk?
PB-460 Crankshaft Bushing
Similar to our PB-455, it is a sealed roller bearing that drives into the back of a stock Oldsmobile automatic crankshaft. This bearing converts your crankshaft into a 4 speed application. The bearing is self aligning to compensate for bellhousing and transmission misalignment about .010" to .015". You must shorten the tip of the input shaft so it won't bottom out in the crankshaft. On some models, the cranks are counterbored to accept the input shaft. This new unit can be driven into place with no machine work. This bearing assembly also fits any G.M. crankshaft in the converter locating hole and can be used when using a motor plate, transmission adapter, etc.. Fits all G.M. input shafts. $69.00

Run to Rund

All Olds blocks should have a spit hole in the pipe plug in front of the distributor gear. IIRC, it is aobut .030". I have an unused Supercars Unlimited cheater pilot bearing I'd sell for $30 if you want to PM me. I was pulling the crank so had it drilled instead. Diostributor gears don't tend to wear out, but if the hole is plugged they could. Also the block cast-in pad the gear sits on could wear. The cam gear would wear along with the dist. gear. I'd use a plug with spit hole.

gearheads78

I using the cheater bearing about 500 miles so far so good but I have been told by some that they have had issues.

When I build the new motor and will use the correct bushing in a 4speed crank.

MN71W30

Cheater bearing,
I talked to a guy at super cars unlimited and he said the only complaints he has had, is guys damaging them with the transmission input shaft by being to rough and blaming the bearing.
I think it's worth a try.

My442

Two answers...the .040" hole needs to be there. Not having it will cause excess wear on the distributor gear.

I had the conversion bearing fail on me in about 500 miles.

First, reverse would grind. Then, it started to make a wield high pitched noise.

I pulled the tranny, and the conversion bearing spun in the I.D. of the crank.

So, does the bearing work? Sort of.

Is it a long term solution? No.

I pulled the crank and had the correct pilot bearing put in - zero issues.

Run to Rund

If I were going to use the cheater bearing I'd red loctite it into the crank.

MN71W30

I didn't want to hear that, but I am very glad you told me. I am pretty tough on my cars, they all see track time and I know it's a PIA but maybe I better pull the carnk and get it over with.
I guess I'll get a hole in the plug too.

MN71W30

That ain't a bad idea.
The motor is out and the pan is off. I guess I should be a man and do it right and not have to worry about it down the road. I got a feeling I would really be mad if I had to pull the motor and do it over.
If I do it now it might save me a trip to the insane asylum.

Run to Rund

It is a lot of work to pull the crank. If you pull the pistons and rods (almost absolutely necessary to prevent scoring the crank with a rod bolt), then you will want to hone the walls and install new rings if the engine was run before. You will pay $100-150 to get the crank drilled and hope they do it completely concentric with the crank main bearings, or you will lose the new pilot bearing/bushing. Very few ordinary "rebuilders" remember that one of the most important procedures is aligning the bellhousing so it is within .003" in and out from top to bottom and side to side, and the same tolerance of the big hole for the tranny to the crank. Lakewood sells offset dowels in .007, .014, and .021" offset and I have always messed around until I got within .001". I drill the dowels, including the stockers, 1/4" or 17/64" and tap them 5/16x18 thread so I can pull them with a slide hammer. Lakewood puts a screwdriver slot into them, but that is useless since they are a press fit into the engine block. A lot of times people with pilot bearing problems don't know the real problem is not the bearing but the bellhousing alignment.

MN71W30

I am sorry to say I've never taken the time to do that and maybe now is the time to learn. I remember losing a piliot bearing on an old SS396 Chevelle I had 20+ years ago and not having a clue what went wrong. I'll study up on it and give it a go.
I managed to pull an Olds crank and re-install without pulling the heads by using an engine puller/leveler attached to the crank and a cherry picker. I was able to spin it out and back in without any scratches. The engine is fresh and never run so pulling a piston won't be the end of the world.
It looks like I'll be pulling the crank, I got a quote for $60 at a local machine shop but never asked them how they will be drilling it. I better follow up on that tomorrow.
Thanks

My442

The correct bearing is BCA7109

Charlie_brown

I'm a newbie at this whole engine mod/building thing. What is the purpose of the cheater bearing over the stock? Is it for use with a manual trans?

MN71W30

Piliot bearings are installed in the rear of the crankshafts in manual transmission cars because the manual input shafts extend into the back of the crankshaft. Automatic car cranks are not drilled to accept a piliot bearing. This means either having the crank drilled or using an aftermarket bearing to avoid pulling out the crank.
That is where the decision needs to be made.

1964f-85

I made a divice out of mild steel tubing with an ID the same as the bushings OD, a matching drill bit and a piece of 1/4" plate steel. The plate is drilled to match the tranny mount bolts on the bellhousing, a hole is drilled with the bit indexed to the centerline of the crank and the tubing is welded at a 90 degree angle to the plate so it is aligned with the hole. Bolt on the bellhousing, then bolt on the tube/plate assemble, then you run the bit into the back of the crank. Make sure you only drill as deep as necessary to drive in the bushing. We have drilled 30 cranks this way and never had a failure and this can be done with the engine still in the car.

My442

Before you put one of those conversion bearings in your car, take a close look at it.

CHEAP chineseum garbage.

gearheads78

Sounds like a great idea

Thats what I thought when I got mine but since its for temporary I used it anyway.

MN71W30

Maybe the Chineseium bearings would last under normal conditions? I got a feeling some of the cars around here lead a tough life.
Dave

My442

Hey, it's your car.

Put anything in it you want.

Just trying to educate folks......

MN71W30

It's easier to learn from others mistakes, but I remember the ones I make much better.
The truth... even if it isn't what we want to hear, is still a good thing.
Dave

citcapp

Keep us posted on how this turns out. I have a forged steel crank that needs to be drilled and will be going into my 455 build for the 48 olds and I will be installing a 5-speed as well. I was not aware of the alignment issue with the bell housing, so I guess I'll be facing the same issue. Oh what fun

Run to Rund

Up to around 1970 the counterbore in the AT cranks is shallow and you can bore the crank .55" deep (using a lathe, not a drill, please) for the cheap Dorman 690-014 Chevy pilot bushing. It has a nice rolled lede and is .75" deep. Of course, you can bore them for the Olds bearing as well, with or without a snap ring retention groove. The groove was introduced around 1970, replacing the earlier method of peening the edge of the hole. Loctite works well instead. Later cranks have a bigger counterbored area and there is not enough meat in the center for that. You can bore them for the Olds/Bower 7109 or the dorman 690-023 bronze replacement bushing. The bronze won't last as long as the bearing if the alignment is perfect and no contamination hits the bearing, but the bronze will last a good while and won't hurt the tranny input in the event of failure.

My442

Drilling than crank in the car is harder than a wedding dick.....