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Pilot bearing, crankshaft

steve from staten island

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Is the same crank on a 383 used for both a auto trans and standard trans? If you wanted to use a auto trans in a standard shift car do you need to remove that pilot piece were the input shaft of tranny goes and if so how do you get it out. the only thing i can think of is threading it and making a strong back--------------------thanks
 
Pilot bushing will not interfere unless it is the ball bearing type at the end of the crankshaft. If you have a flex plate and converter testing the fit before installation of the transmission would be advised. I have done this swap with the /6 and A block and had problems with the converter nose fitting into the manual transmission crankshaft. I have yet to have a problem with B engine cranks but would still check it.
 
3B,thanks i had the converter bolted up but there is a slight space between the flex plate and converter. The converter bolts made up and pulled the flex plate up tight to it,,,,but when i took the tranny off i checked it out.The flex plate does not sit flush,the converter needs to go into the crank about another 3/16 to 1/4 inch. Is that piece in the end of the crank removable or is it a machined part of the crank
 
The transmission and engine bolted together should have 1/4 play before the coverter bolts to flex plate. This protects the Thrust bearing and crank from excess energy. If your looking to get bearing out of crank fill the bearing with heavy axel grease. Then take a wood dowel the close diameter of the center hole of the pilot bearing put in hole press lightly then wack with a hammer it will use the grease to force the bearing out.
 
Look for thread meshing RB440 to 4spd. The correct dimensions for a automatic crankshaft end are shown in a post on the thread. The thread is in this same section.

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See post 10 in the above mentioned thread.
 
Steve,I understand the play required but i thought when you bolt the converter to flex plate the converter should slide right up to it. Mine does not as the middle piece of the converter is hitting the inside of the crank. The converter fits the trans and lines up with flex plate but could it be the wrong converter as its a rebuilt?

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Thanks for the links,i think i have the wrong converter. It seems the center of the converter that fits into the crank is to deep and is hitting the inside of crank. With the flex plate bolted to crank,if you take the converter and put it up against the flex plate it does not go flush against it. There is a little space all the way around.
 
I think I would check a couple things before getting a new converter. Is the converter all the way in the transmission: three clicks? Is the flex plate the correct direction hole 180 from drain? Is it the correct diameter, 130 ring gear teeth for a 383? Im not sure if this next thought would make a difference for installing because I have always made sure I had the correct match-up, but do you have an internal ballance crankshaft with a neutral ballance torque converter? Or an external ballance crank with a external ballance torque converter? They must match or vibrate like hell. Not sure if it would also interfere with installation like you are experiencing. Also if you really want to pull the pilot bushing just get a pilot bushing puller. You can rent one at most parts stores. Most 383 forged cranks Ive seen had the bushing installed at the factory weather it was an automatic or manual transmission. So it should not be an issue in your case.
 
Will the converter fit into the hole in the end of the crankshaft with the flex plate off? Unless someone has stuck the new style pilot bearing in the very end of the crankshaft the bushing will not interfere with torque converter installation. I have found the outer hole in manual transmission crankshaft to be smaller in diameter than that of automatic transmission crankshaft's. The torque converter snout has to enter the hole in the crankshaft for it to properly bolt to the flex plate. This is why it it is important to determine the type of crankshaft you have and the type of transmission your are going to use when doing conversions. Almost any good machine shop can make the required corrections with the crankshaft removed and if lucky you may find one that will with the engine assembled but I would not count on it.
 
the converter will not mesh up with the flex plate mount holes...there will be a space, you put the bolts in and the plate will "flex" to the converter when you tighten the bolts.

You can use an auto trans with a manual crank, but not the other way around
 
A383wing that is not why they are called flex plates. Doeing that to an SFI or any plate would worp it into a piece of junk and promote cracking due to unnecessary stress. Also your are pushing the converter back and taking up the pump to converter clearance required to keep from making a mess of the front pump drive.
 
I think the question for me is this. Is the crank from a auto transmission different that a standard trans. From what i can see its not the pilot bearing but rather the machined area in the flanged area of the crank. It needs to be deeper or the snout of the converter needs to be smaller
 
I think the question for me is this. Is the crank from a auto transmission different that a standard trans. From what i can see its not the pilot bearing but rather the machined area in the flanged area of the crank. It needs to be deeper or the snout of the converter needs to be smaller

What are you getting when measuring the depth of the flange c'bore?
 
I am reading that people are saying the torque converter nose goes into the pilot hole of the crank shaft? Wow this is new to me. I have changed automatic 69 RR to manual, and 70RR manual to automatic and never saw anything like that. I dont claim to know everything but the torque converter does not directly contact the crankshaft in any shape way or form. It bolts to the flex plate, the flex plate bolts to the crankshaft, thats it. The way to install it is in this fashion: turn the torque converter until it is all the way into the pump of the transmission. Usually three clicks. Then bolt the flex plate to the crank shaft noting the alignment hole location. Then make sure the torque converter drain is at the oposite of the locater hole of the flex plate. I then mate the transmission to the engine but dont torque it to specs yet. Make sure the torque converter drain remained in its location. Put in the flex plate to torque converter bolts all the way in but loose. Once installed, torque all of them, then torque the engine bolts as well. Install the access cover and you are done. As far as I know all big blocks are the same. Maybe in the later 70s with cast cranks it is a different story, but I dont think so. I have changed out a cast crank for a forged crank and it was machined the same on the rear flange. The cast crank did not have a pilot bushing as all forged cranks did. That is the only difference I know of in appearance. The cast cranks were external balanced the forged were internal, I mentioned in my previous post to make sure you use the correct torque converter for forged or cast crank shaft. That is a huge must do! Hope this helps

P.S. the internal ballanced crankshaft torque converter has NO balance wheights on it (it is neutral ballanced). The external ballanced crank shaft torque converter has ballance wheights on the face of it.
 
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Get a decent caliper tool. One that also measures depth. That and a straight edge will tell you where the problem is. My bet is the snout of the torque converter is not going into the flange on the crank. Your pilot bearing should not make any difference. . If you measure and find the T.C. snout will not quite go into the crank flange ( maybe paint or snout flange a little buggered) you can file off evenly around the snout flange till it fits......................................MO
 
Check out the response from Mopar 3B above. The thread he's referring to has an illustration and measurements that might help out. You can find it easy by going to my profile and clicking see more on the thread. Glad i'm not the only one with mating issues!(mechanical of course!):eusa_doh:
 
Thanks for the help. I guess when its said you never stop learning,that was the truth.. What i found was the pilot bearing sticking out about a 3/32 of a inch. I took it out and now the converter fits better. However it still does not fit completely flush. There is about 50 thousands space (looking at it by eye) between the flex plate and converter due to the fact that the converter snout bottoms out in the end of the crank.
Im on my way to look at the original crank that came out of the car and see if that tells me anything. Will let you all know
 
I am reading that people are saying the torque converter nose goes into the pilot hole of the crank shaft? Wow this is new to me. I have changed automatic 69 RR to manual, and 70RR manual to automatic and never saw anything like that. I dont claim to know everything but the torque converter does not directly contact the crankshaft in any shape way or form.

uh, yea, it does, snout of torque converter goes into large hole of crankshaft and bottoms out. That will leave you with maybe a 1/4" gap between flex plate and bolt holes in converter. Install bolts into flex plate at all 4 locations and this will bring the plate up to the converter snug. This keeps the converter into the end of the crank by the flex plate constantly pulling converter towards front of car.

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A383wing that is not why they are called flex plates. Doeing that to an SFI or any plate would worp it into a piece of junk and promote cracking due to unnecessary stress. Also your are pushing the converter back and taking up the pump to converter clearance required to keep from making a mess of the front pump drive.

you are pulling the converter forward, not pushing it rearward...the flex plate keeps the converter pulled into the crank...the plate does flex when pulled up tight with converter bolts
 
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