65 Pilot Bearing Question
 

Hello, I was hoping someone can shed some light on my situation. I have a extra re-built 65 389 on a stand ready to put into my car. The motor was rebuilt several years ago. At that time I remember looking at the back of the crankshaft and not noticing any issues. When I went to install the 7109 pilot bearing, it's not even close to properly fitting. Then doing some online digging, I saw Pontiac around that time, some were machined for pilot bushings and some not. I do not know which Number crank is this engine. By looking at this picture can anyone point me in the right direction? Thanks- Mark

Some cranks in auto trans equipped engines were not sized for the standard-issue pilot bearing. I ran into this over 40 years ago with a '67 400 that came out of a Catalina. I simply measured the crank and had a generic oilite bronze pilot BUSHING turned down to fit. It worked perfectly. Much easier than changing crankshafts!

Thanks for the reply, by looking at that picture is that the case?

I believe so looking at the picture.
Looks like the crank was always intended for a Turbo 400 style Converter.
The smaller hole inside the crank looks too deep to work with a normal pilot bearing and the diameters look wrong to me to match up properly.

Tom V.
Just going by a picture though without a factory pilot bearing next to the crank for dimensional comparison.

See if these pictures help. Hard shot to get.

1) It does not look good without a special oilite bushing based on the first picture.

2) That being said, here is what you need to do:

a) Mount the Bellhousing on the trans and get a input shaft length from the inside of the
bellhousing flat surface to the end of the shaft. You can also do the outside surface but
you will have to add the thickness of the bellhousing you are using if you do that method.

So then you will how how far the input shaft nose sticks into the crankshaft.

If it goes in same as the distance and bearing position in picture #2 you will need a
bushing ring to go around your pilot bearing or a thick bushing to fit the large outside diameter and a correct hole size for the input shaft nose diameter.

If the trans extends all the way to the second deep pocket then you will need a custom bushing to fit the smaller diameter vs the pilot bearing that fits into the crank.

I can't tell you what you have here without you doing measurements.

Tom V.

Here's what I did. It was kind of mickey mouse, but it got me going for quite awhile. I had a tool made to put the bushings on, then I had the outside diameter turned down to meet the crank dimension. (with a tight fit). If you do this I would look for a wider bushing, but this worked.

Mickey Mouse (me too)
 

Old Man Taylor,
My homemade tool consists of a piece of fine-thread 3/8” all-thread rod and the bearing races from a bicycle front wheel axle. Mount the oversized bronze bushing loosely between the bearing races on the rod, mount it in a vise. Using a Dremel tool with a rotary drum mandrel, hold the drum diagonally across the face of the bushing and spin the bushing at high speed, grinding in small increments.

Thanks for the input, I'm weighing my options.

I stumbled across this in a couple of 442 forums. It's offered by Dick Miller Racing.


"Stick shift pilot bearing adapter. A new solution to an old problem. Convert a GM automatic transmission crankshaft to a manual shift crank without taking the crank out of the block. Knurled for a sure fit with self alignment for a perfect fit and smooth running and shifting. Requires modest shortening of input shaft with common tools or rough drilling the crankshaft. Also for engines that are using a midplate resulting in the transmission being moved rearward and not engaging the stock pilot bearing far enough. Fits Oldsmobile 260-455, Buick 350-455, Cadillac 400-500, Pontiac 326-455, and Chevrolet 305-502.

TECH TIP: To properly install either DMR-5022 coat the knurled edges with red Loctite before driving the bearing into the crank.

https://dickmillerracing-com.3dcarts...pter_p_49.html