Does anyone know what the diameter is of a 1963 Muncie four speed input shaft end that goes in the pilot bushing?I'm going to bolt a 1963 Muncie to a 1960 Chevy 283 engine and there's no pilot bushing in the crank.The motor numbers say the car was a powerglide but the hole in the crank is 1.090" in diameter which according to data isn't the size a powerglide crank hole should be.There are about ten different size pilot bushings listed for a 283 Chevy so I'm totally confused as to which one to get.Also would like to know what the tolerance should be between the pilot shaft and the bushing. I've read suggestions all the way between .002" and .008" . Thanks in advance for any help.

 

The correct dimension for the oilite bronze pilot bushing is .592" I.D. x 1.094" O.D. NAPA #BK-615-1161 or Federal-Mogul #PB-656-HD. Make sure the bushing doesn't stick to a magnet.

 

I'm in total, 100% agreement with what John says. I AM NOT aware of different sizes of pilot bushings/bearings for a Chevy V8 engine---------------EXCEPT, for engines which had a Turboglide behind them. The late 50s-early 60s Turboglides were not extremely common, and for the most part had an unsatisfactory reputation (61 was the last Turboglide). But it is my understanding that the hole in the rear of the crank for a Turboglide (John can confirm or deny this) is different (larger) than the hole for a manual tranny or PG. Thus, in all my years of experience with Chevy engines, they ALL (except Turboglides) use the same pilot bushing/bearing. Also, they are supposed to be a very tight interference fit. The best installation method I've found is to use an old input shaft. Slip the bushing onto the input shaft and then with a big hammer, very carefully drive the bushing into the crank hole until the bushing is even with the outer edge of the hole.
Also, as John pointed out, if a magnet will stick to the bushing DO NOT USE IT!!!!!!!!!!

AND, while we're on the subject, there are both bushings and bearings available for the pilot. LOTS of discussion and debate on this issue! I am a VERY STRONG ADVOCATE FOR NOT USING THE BEARING!!!!! The bearing works fine, and lasts longer when thoroughly greased. But when a bearing fails, and I've seen several failed bearings, it's bad news and bad for the pilot end of the tranny input shaft. The hole in the bushing will wear and simply become enlarged with NO DAMAGE to the pilot of the input shaft.
Last, a bushing or bearing has a tapered hole on ONE END. The taper faces the transmission.

Below is what a disintegrated pilot bearing will do to an input shaft.

 

just wondering , are they sintered bearings? They seem to be the ones most recommended because of they're oil soaked. Thanks.

 

just wondering , are they sintered bearings? They seem to be the ones most recommended because of they're oil soaked. Thanks.

 

I think the shaft diameter is .590"and should be perfect for the .592 bushing. I guess the 1.094 0d bushing will fit in my 1.090 crank hole Thanks

 

I don't know what a Turboglide is, but Dorman has a bushing for a Powerglide conversion. Specs:

Dorman # 690034 (14651,6900341)-Inside diameter .593", Outside diameter 1.060". Auto trans conversion, Powerglide to manual.

 

If you're mating a 63 transmission to an early bell housing, the front bearing retainer on the transmission is a different size than the hole in the bell housing.

63 was unique and used a smaller bearing and bearing retainer than other units so the transmission won't center properly in the hole in the housing.

 

Here is a pic of the bushing John is describing. They are also available at many of the other part houses.

 

That is correct, but if you change the original small bearing retainer to a Saginaw 3 speed bearing retainer (591620 or 3741458), the transmission will bolt up perfectly. I just finished doing one just like this.

Terry

 

The last pilot shaft bushing I installed I tried the trick of leaving it in the deep freeze the night before and taking it out just prior to seating it. It did go into the crank pretty easily that way. Hate pounding very hard on the back of a crank with that thrust bearing in there.

 

I failed to mention that, and I totally agree with the freezing before installing.

 

This thread wins the "Amazing Forum" award for depth of knowledge.

 

Excellent idea to keep the bearing in the freezer overnite. And here is an excellent way to transport the bearing from your freezer to the engine. Available at drug stores and pharmacies, it's a gel pack that you can keep in the freezer as well. It is flexible so you can wrap it around the bearing. It's also a good idea to wear gloves so you don't transfer body heat to the bearing.


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John, The .592 x 1.094 should be good if I can get the 1.094 OD into the 1.090 hole in the crankshaft. It's the OD that was a few thousands different in some of the bushings that I looked up. thanks for the info.

 

DZ Auto As I told John my confusion about the bushing was due to different OD'S of different listings of bushings.They ranged from 1.093 to 1.096. Maybe they calibrate their micrometers differently! Anyway, thanks for all the info. I considered using a needle bearing. Your picture changed my mind. Thanks again.

 

Buns, Evidently my engine's crank wasn't an automatic crank. The hole is 1.090" which is way too big for the 1.060" bushing to convert to manual from automatic. Thanks for the info

 

The Muncie is attached to a 400 small block now and has the larger bearing retainer.I'll be using the Muncie with that bell in the 283.Good advice for 63 Muncie owners. Thanks

 

Mike, thanks for the bearing pic. ( Great looking 67 !)

 

Your welcome and thanks. One last pic, don't let anyone sell you this bushing - it more silver in color and it's magnetic!