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Crankshaft to Gearbox Pinion Shaft Roller Bearing?
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Author:  Tom Bishop [ Thu Jun 27, 2019 11:02 pm ]
Post subject:  Crankshaft to Gearbox Pinion Shaft Roller Bearing?

On a 1965 Valiant Custom 200, basically the same car as a Dodge Dart, with /6 motor and manual 3 speed box:

Does anybody know the size or part# for the little roller bearing in the rear of the crankshaft that supports the gearbox pinion shaft?

On the Net, it does seem a rather elusive part to reference.

Thanks for the help.

Regards

Tom

Author:  Badvert65 [ Fri Jun 28, 2019 4:28 am ]
Post subject:  Re: Crankshaft to Gearbox Pinion Shaft Roller Bearing?

It is generally a bushing (pilot bushing) as opposed to a bearing. I have heard that there is a bearing available now that will work there, from a late model Dodge truck application. This supports the front of the transmission input (pilot) shaft. I don't have the part numbers, but I can check around for them.

Author:  GregCon [ Fri Jun 28, 2019 5:24 am ]
Post subject:  Re: Crankshaft to Gearbox Pinion Shaft Roller Bearing?

In later years they did go to a needle bearing setup....but I'm not sure you can just use it because it fits in a register that is closer to the trans than the earlier bronze bushing.

I've also seen cases where the needles, which are way harder than sintered bronze, chew up the trans shaft.

It sounds sexy to use a roller bearing but personally...I'd stick with the bronze bushing. Keep in mind the only time there is movement along this bearing is when the clutch is 'In'.

Author:  DadTruck [ Fri Jun 28, 2019 6:44 am ]
Post subject:  Re: Crankshaft to Gearbox Pinion Shaft Roller Bearing?

photos of the transmission pilot shaft
bushing that goes into the cranks pilot hole
and the roller bearing that goes into the crank register
are at the links below

http://www.brewersperformance.com/prodd ... prod=PB329

http://www.brewersperformance.com/prodd ... rod=PB5300

if it is a '65 motor/crank the issue with using the register bearing will be the
register size. These bearing fit the large register crank that went in to service in 1968.

for the pilot bushing, if the crank was not from a manual transmission car, check the hole
for depth and size, some cranks from automatic transmission cars are drilled but not honed to size.

Greg Con,, do you have photos or a link to a discussion of
Quote:
I've also seen cases where the needles, which are way harder than sintered bronze, chew up the trans shaft.


I have used the register bearing in a crank will no ill effects, and Brewers, a very respected mopar transmission shop recommends the register bearing
for use when the crank pilot hole is not the correct size/depth.

Author:  GregCon [ Fri Jun 28, 2019 8:58 am ]
Post subject:  Re: Crankshaft to Gearbox Pinion Shaft Roller Bearing?

I don't have any links but we (when I used to hang out at my friend's transmission shop) would see them from time to time. That said, they could have chewed up for other reasons....what you find is the average person drives his car/truck until it no longer moves at all which ensures complete destruction and makes root cause analysis pretty tough.

I'd be curious to know if the OEM's adopted a different or 'harder' material for transmission shafts when they moved to roller bearings.

I really am not sure why a roller bearing would be used regardless. Rollers give way less surface contact area than a bushing. I could see then benefit of a roller if you sat at 6000RPM with the clutch pedal in for a long time.

Author:  DadTruck [ Fri Jun 28, 2019 11:41 am ]
Post subject:  Re: Crankshaft to Gearbox Pinion Shaft Roller Bearing?

Quote:
OEM's adopted a different or 'harder' material


An a833 input shaft is a steel forging. Handles all the engine torque, so it is already plenty tough.
Also keep in mind that whether it is a bushing or a bearing, its only purpose is to align the mechanicals in the transmission with the
center of the crankshaft. Preventing or controlling side loading is not the purpose of the bearing or bushing. In fact that is why
one would use a dial indicator to verify that the main bore of the flywheel housing is concentric with the center of the crankshaft.
And use off center dowels if it is not.

as far as why the OE's changed from a bushing to a bearing.
a complete guess is that the OE's can buy a bushing for .30
and a bearing assembly for $1.50

so why use the more expensive part?
To simplify the manufacturing process.
The crank register is finished as it is used to center the torque converter.
Why buy, install and maintain a machining process to manufacture a locating feature
just for manual transmission vehicles, when the one already present for the automatic transmission
vehicles can work just as well. Another consideration is now there is only one crankshaft being delivered to the engine assembly line, where
previously there world have been two, unless all cranks had a fully finished register and a fully finished pilot bore,
and we know that was not how it was done. Chrysler had to keep the cranks with finished pilot holes separate from those that were not finished.
Not an easy thing to do on parts that looked virtually identical. I bet there were mix ups from time to time.

so my assumption is the more expensive bearing was introduced as a cost savings, due to streamlining the manufacturing process and error proofing,
If there is only one crankshaft, you won't get an automatic crank in an engine destined to be coupled to a manual transmission.

Author:  Killer6 [ Fri Jun 28, 2019 1:48 pm ]
Post subject:  Re: Crankshaft to Gearbox Pinion Shaft Roller Bearing?

Isn't the bearing assy. a sealed unit on the later/magnum engines??? I don't think there are open "needles" to ride directly on the input shaft. If You have a true early crank, it's out unless You want to machine the converter hub bore out to the larger dimension (which [i]can[i]be done). Either way,
if You've got an early auto crank w/an unfinished pilot bore, You've got some work to do...........

In your case, You just need a new bushing, not sure why it's difficult to find. Haven't looked for one Myself for a decade or so tho', so......????

Author:  Tom Bishop [ Sat Jun 29, 2019 9:18 am ]
Post subject:  Re: Crankshaft to Gearbox Pinion Shaft Roller Bearing?

This Car had a Needle Bearing fitted.
I pulled it when rebuilding the motor and Remember putting it away safely as a sample.

That was a year ago.......

Now the only problem is this grey old noggin cant remember where that safe place is. :oops: :oops: :oops: :oops:

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