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340 Pilot Bushing or Bearing???

Posted By: sixpackman

340 Pilot Bushing or Bearing??? - 07/02/20 10:49 PM

Hello,

I need some help figuring out weather to use a Pilot bushing or a bearing? I've been told if I use a bearing I will need to cut the tip off trans input shaft??? Still can't understand that!!!

If my crank is an auto crank not a manual and my motor is already built, Is there a way to rem it out to except a bushing?

The reason for this post is to understand my options sense the motor builder didn't check or install it.

Thanks for any help you could give me.

Thanks again,
Scott
Posted By: gtx6970

Re: 340 Pilot Bushing or Bearing??? - 07/02/20 11:12 PM

The only time you NEED to chop the trans input shaft off is if the crank is not drilled deep enough for a pilot bushing.

IF thats the case you then have NO other option than a roller bearing in the back of the crank
Posted By: sixpackman

Re: 340 Pilot Bushing or Bearing??? - 07/02/20 11:27 PM

I was thinking the same on chopping off the input shaft. The reason I'm asking is the paper that came with the bearing said you needed too?? And of coarse the engine builder kept the paperwork on it so I can't verify it.

It's a new crank to me sense my old one had welds and a crack in it. I prefer using the bearing but never have in the past and wanted a sanity check.

Thanks for the input.
Posted By: gtx6970

Re: 340 Pilot Bushing or Bearing??? - 07/02/20 11:29 PM

Originally Posted by sixpackman
I was thinking the same on chopping off the input shaft. The reason I'm asking is the paper that came with the bearing said you needed too?? And of coarse the engine builder kept the paperwork on it so I can't verify it.

It's a new crank to me sense my old one had welds and a crack in it. I prefer using the bearing but never have in the past and wanted a sanity check.

Thanks for the input.


Measure the depth of hole in the back of the crank before you cut anything

If it is deep enough you can still use the roller bearing with no issues if you so desire
Posted By: crackedback

Re: 340 Pilot Bushing or Bearing??? - 07/03/20 03:58 AM

If the opening in the crank is deep and wide enough to accept the input shaft pilot, no need to cut it.

You could probably get a grinder and open it up if need be.
Posted By: PhillyRag

Re: 340 Pilot Bushing or Bearing??? - 07/03/20 05:49 AM

Originally Posted by crackedback
If the opening in the crank is deep and wide enough to accept the input shaft pilot, no need to cut it.

You could probably get a grinder and open it up if need be.


Probably OK with grinder, BUT ONLY if you need to increase a few thousands. Beyond that, I doubt you get a nice centered opening. That may lead to alignment issues with the mating parts.
Posted By: crackedback

Re: 340 Pilot Bushing or Bearing??? - 07/03/20 06:50 AM

The pilot doesn't have to touch anything, there is no alignment issue when using the big bearing like the dakotas use. Hot dog down a hallway analogy here. Doesn't touch the walls at all.


The bushing/pilot isn't in play here at all unless the OP is asking about the smaller bearing style that aligns the pilot tip. I think they are talking about the type of pilot bearing that fit in the converter register and captures the smooth section just in front of the splines, not the pilot tip like the bushing does.

https://www.carid.com/1994-dodge-ram-transmission-parts/national-clutch-pilot-bearing-98317886.html
Posted By: fastmark

Re: 340 Pilot Bushing or Bearing??? - 07/03/20 09:58 AM

The first thing you do is measure the depth of the small hole in the crankshaft. It should be 1.750” deep to accept the input shaft. The correct diameter size hole for the original style pilot is .940. Anything less than that and an original style will not work. Most auto cranks of the era were only approximately .908. Some cranks had no hole at all. If it’s not deep cut it off or drill it deeper. Drilling is hard to do without a drill press. You last choice will be to cut the end of your input shaft off enough to clear and get the later style bearing that presses in the larger diameter hole when the converter hub normally goes. Good luck.
Posted By: PhillyRag

Re: 340 Pilot Bushing or Bearing??? - 07/04/20 07:49 AM

Originally Posted by crackedback
The pilot doesn't have to touch anything, there is no alignment issue when using the big bearing like the dakotas use. Hot dog down a hallway analogy here. Doesn't touch the walls at all.

Quote
So putting a steel shaft (input shaft end) into a bearing (with needle bearings); alignment isn't an issue. Since when?



The bushing/pilot isn't in play here at all unless the OP is asking about the smaller bearing style that aligns the pilot tip. I think they are talking about the type of pilot bearing that fit in the converter register and captures the smooth section just in front of the splines, not the pilot tip like the bushing does.

https://www.carid.com/1994-dodge-ram-transmission-parts/national-clutch-pilot-bearing-98317886.html
Posted By: fastmark

Re: 340 Pilot Bushing or Bearing??? - 07/04/20 10:38 AM

Ok. I need to update my post in a new one. I did not see the OP state this was a 340. All of the 340 steel cranks I have at my shop are all properly drilled for a pilot bearing from the factory. Most have a pilot bearing installed even though used behind and auto from the factory. Now, if you got a 318 or 273 steel crank instead, it may not have one. In that case, I hope you balanced it. Where did the crank come from?
Posted By: crackedback

Re: 340 Pilot Bushing or Bearing??? - 07/05/20 12:57 AM

Originally Posted by PhillyRag
Originally Posted by crackedback
The pilot doesn't have to touch anything, there is no alignment issue when using the big bearing like the dakotas use. Hot dog down a hallway analogy here. Doesn't touch the walls at all.

Quote
So putting a steel shaft (input shaft end) into a bearing (with needle bearings); alignment isn't an issue. Since when?



The bushing/pilot isn't in play here at all unless the OP is asking about the smaller bearing style that aligns the pilot tip. I think they are talking about the type of pilot bearing that fit in the converter register and captures the smooth section just in front of the splines, not the pilot tip like the bushing does.

https://www.carid.com/1994-dodge-ram-transmission-parts/national-clutch-pilot-bearing-98317886.html


The big bearing uses the converter register, NOT, the OEM area where the smaller bronze bushing is installed. It's why you can cut off the end of the input shaft when using the BIG bearing... If the oem crank opening is wide enough and deep enough that section is now INSIGNIFICANT to alignment and operation! hot dog in a hallway... Also why you can grind it out if you choose to do so using the dakota bearing.


I used these register bearings on 360 cars all the time.

The red area is where the OEM bronze captures, blue where the Big dakota bearing captures.





Attached picture bushing area.jpg
Posted By: PhillyRag

Re: 340 Pilot Bushing or Bearing??? - 07/05/20 06:31 AM

Originally Posted by crackedback
Originally Posted by PhillyRag
Originally Posted by crackedback
The pilot doesn't have to touch anything, there is no alignment issue when using the big bearing like the dakotas use. Hot dog down a hallway analogy here. Doesn't touch the walls at all.

Quote
So putting a steel shaft (input shaft end) into a bearing (with needle bearings); alignment isn't an issue. Since when?



The bushing/pilot isn't in play here at all unless the OP is asking about the smaller bearing style that aligns the pilot tip. I think they are talking about the type of pilot bearing that fit in the converter register and captures the smooth section just in front of the splines, not the pilot tip like the bushing does.

https://www.carid.com/1994-dodge-ram-transmission-parts/national-clutch-pilot-bearing-98317886.html


The big bearing uses the converter register, NOT, the OEM area where the smaller bronze bushing is installed. It's why you can cut off the end of the input shaft when using the BIG bearing... If the oem crank opening is wide enough and deep enough that section is now INSIGNIFICANT to alignment and operation! hot dog in a hallway... Also why you can grind it out if you choose to do so using the dakota bearing.


I used these register bearings on 360 cars all the time.

The red area is where the OEM bronze captures, blue where the Big dakota bearing captures.


Quote
But the input shaft end is still inserted into the bearing. Again; alignment between those 2 parts not important?
Posted By: crackedback

Re: 340 Pilot Bushing or Bearing??? - 07/05/20 07:12 AM

Originally Posted by PhillyRag
Originally Posted by crackedback
Originally Posted by PhillyRag
Originally Posted by crackedback
The pilot doesn't have to touch anything, there is no alignment issue when using the big bearing like the dakotas use. Hot dog down a hallway analogy here. Doesn't touch the walls at all.

Quote
So putting a steel shaft (input shaft end) into a bearing (with needle bearings); alignment isn't an issue. Since when?



The bushing/pilot isn't in play here at all unless the OP is asking about the smaller bearing style that aligns the pilot tip. I think they are talking about the type of pilot bearing that fit in the converter register and captures the smooth section just in front of the splines, not the pilot tip like the bushing does.

https://www.carid.com/1994-dodge-ram-transmission-parts/national-clutch-pilot-bearing-98317886.html


The big bearing uses the converter register, NOT, the OEM area where the smaller bronze bushing is installed. It's why you can cut off the end of the input shaft when using the BIG bearing... If the oem crank opening is wide enough and deep enough that section is now INSIGNIFICANT to alignment and operation! hot dog in a hallway... Also why you can grind it out if you choose to do so using the dakota bearing.


I used these register bearings on 360 cars all the time.

The red area is where the OEM bronze captures, blue where the Big dakota bearing captures.


Quote
But the input shaft end is still inserted into the bearing. Again; alignment between those 2 parts not important?



REALLY??? Way to parse the sentence and create an issue which was ANSWERED in said sentence... I'll try again and be done. I was talking about the alignment where the OEM bronze bushing would be which is NO LONGER present or needed. The alignment in the register bearing set up is just fine. Pick away if you like. Using the register style makes the OEM hole in the crank for aligning the tip a moot point. That's the hot dog down a hallway... carry on with whatever you like... LOL
Posted By: moparx

Re: 340 Pilot Bushing or Bearing??? - 07/05/20 03:08 PM

a question i always wanted to ask, but never did,
can ALL cranks use the roller bearing, in other words, are ALL cranks machined for the torque converter snout ?
not trying to muddy the waters any more than they already are, just wondering.
beer
Posted By: fastmark

Re: 340 Pilot Bushing or Bearing??? - 07/05/20 05:33 PM

Yes. Some are a little tighter by a .0001 or so.
Posted By: Sniper

Re: 340 Pilot Bushing or Bearing??? - 07/05/20 05:39 PM

You forget about the early LA cranks,
Posted By: gtx6970

Re: 340 Pilot Bushing or Bearing??? - 07/05/20 05:50 PM

Originally Posted by moparx
a question i always wanted to ask, but never did,
can ALL cranks use the roller bearing, in other words, are ALL cranks machined for the torque converter snout ?
not trying to muddy the waters any more than they already are, just wondering.
beer


As far as I know, Yes.
the big register is originally for torque conv alignment so to speak
it wasnt till maybe the 80s is when the roller bearing showed up for manual trans use
Posted By: moparx

Re: 340 Pilot Bushing or Bearing??? - 07/06/20 03:49 PM

thanks for the responses guys ! i now know the answer to my question. up
beer
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