Author Topic: Bad news on my 427/452  (Read 606 times)

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AlanCasida

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Bad news on my 427/452
« on: September 20, 2020, 12:24:13 PM »
What is going on here? I was trying to get #5 main cap off and I noticed the crank had a lot of end play. I checked and it has .080" run out! I pulled #3 main cap and the thrust surface of the crank is ruined...AGAIN! I had to replace the OEM crank last year for the same reason. I thought I found the problem in the torque converter snout not having the trailing edge of the pump drive not chamfered. I chamfered it and reused it. When I put the motor in the car I tripled...quadruple checked the clearance on the converter and it had .125". I don't know if the converter was ballooning or what but the crank is definitely ruined.  >:(   
« Last Edit: September 20, 2020, 12:27:51 PM by AlanCasida »

RJP

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Re: Bad news on my 427/452
« Reply #1 on: September 20, 2020, 01:16:51 PM »
Alan, Are you running a C6? If so check this one thing first. See if the input shaft is in the correct position. On early C6s, say before 74 or 75 the input shaft can be installed either way as they are 31/31 spline. The correct position is the short spline end goes into the converter, the long spline goes into the forward clutch hub. If this is reversed where the input is in backwards the shaft will load the converter and will result in what you now have. BTW the later input shafts are 31/30 spline so they cannot be installed wrong. May not be your problem but it is worth checking. So sorry for the carnage. I know how frustrating [and expensive] it can be.

AlanCasida

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Re: Bad news on my 427/452
« Reply #2 on: September 20, 2020, 01:26:21 PM »
Alan, Are you running a C6? If so check this one thing first. See if the input shaft is in the correct position. On early C6s, say before 74 or 75 the input shaft can be installed either way as they are 31/31 spline. The correct position is the short spline end goes into the converter, the long spline goes into the forward clutch hub. If this is reversed where the input is in backwards the shaft will load the converter and will result in what you now have. BTW the later input shafts are 31/30 spline so they cannot be installed wrong. May not be your problem but it is worth checking. So sorry for the carnage. I know how frustrating [and expensive] it can be.
Thanks for the info! I went out and checked and it is installed correctly. I did notice there is a shiny ring on the pilot snout of the converter that may indicate it was in contact with the pilot bushing area of the crankshaft...or it might be from me sliding it on the floor, hard to tell.
PS those bolt marks on the converter were there from when I had the OEM bolts in the flywheel. I should have painted over them to see if they still hit.
« Last Edit: September 20, 2020, 01:28:35 PM by AlanCasida »

My427stang

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Re: Bad news on my 427/452
« Reply #3 on: September 20, 2020, 01:34:02 PM »
Man, that stinks.  If the shaft is good, I think I'd be giving up on that converter at this point.  However, is there any chance that  you have an oddball flexplate or something?  Could be all converter design, but hitting the bolts previously, snout needing to be clearanced, seems to be something in that combo doesn't belong
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RJP

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Re: Bad news on my 427/452
« Reply #4 on: September 20, 2020, 01:35:40 PM »
Input shaft installed correctly...OK, now perhaps you need to check the torque converter hub engagement into the front pump. If the bevel of the inner pump gear is not facing forward it too will load the converter wrong. The 'witness' marks on the converter don't look normal. I think the tea leaves are trying to tell you something. 

AlanCasida

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Re: Bad news on my 427/452
« Reply #5 on: September 20, 2020, 01:45:14 PM »
Input shaft installed correctly...OK, now perhaps you need to check the torque converter hub engagement into the front pump. If the bevel of the inner pump gear is not facing forward it too will load the converter wrong. The 'witness' marks on the converter don't look normal. I think the tea leaves are trying to tell you something.
I think it is but I'll have to double check it. The odd thing is I had my 428 in it for a little while and the thrust bearing is ok in it. I had to check it when I found this last year. I never raced it but I did buzz it pretty good on the street a couple of times. I think the witness marks came from when I had the 428 in it. I was using an OEM flexplate and OEM bolts. The bolts stick out past the flexplate a little and the front of the converter is pretty much flat with slight concave curvature towards the pilot hub.
« Last Edit: September 20, 2020, 02:01:44 PM by AlanCasida »

Rory428

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Re: Bad news on my 427/452
« Reply #6 on: September 21, 2020, 01:56:07 AM »
Something funny going on there, I used nothing but OE Flexplates and crank bolts, and NEVER seen any marks showing any contact between the flexplate /or bolts, and the convertor .
1978 Fairmont,FE 427 with 428 crank, 4 speed Jerico best of 9.972@132.54MPH 1.29 60 foot
1985 Mustang HB 331 SB Ford, 4 speed Jerico, best of 10.29@128 MPH 1.40 60 foot.
1974 F350 race car hauler 390 NP435 4 speed
1959 Ford Meteor 2 dr sedan. a;; stock 332 2 barrel2 speed FordOMatic

manofmerc

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Re: Bad news on my 427/452
« Reply #7 on: September 21, 2020, 04:39:14 AM »
I had a similar issue with my 452 a few years ago .My flex plate broke it made all kind of noise raised hell ! Well something had to cause this so I looked and looked .Come to find the convertor (TCI) was rubbing the input shaft you could see inside at the snout where it made contact with the input shaft and the input had a worn spot too .I took it to a local convertor shop they said tci took a Chrysler convertor and made it fit a ford .They used the Chrysler since it was furnace brazed. My nice 428 crankshaft was fried also .On my 460 drag car I had another tci convertor balloon it wiped out my crank also . No more tci for me I use ATI so far no problems .You will get it up and running again it might cost some $$$$ but that's how it goes sometime good luck to you ! Doug