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Crankshaft repair?? #2741365
02/09/20 08:32 PM
02/09/20 08:32 PM
Joined: Aug 2009
Posts: 2,036
Mooresburg, Tn
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'72CudaRacer Offline OP
top fuel
'72CudaRacer  Offline OP
top fuel
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Joined: Aug 2009
Posts: 2,036
Mooresburg, Tn
I just purchased a used short block assembly (500ci MP crate engine) that had damaged the thrust bearing. The crank looks to be worn down on the rear of the thrust surface. (a new thrust bearing fits nice in the saddle, but still a lot of end play) I can measure it when I get the engine disassembled, but the crank looks worn there. I suspect the drive shaft was too long. Is this something that can be repaired, or is it junk? It is a 4.15 stroke crank, most likely a $1000 part if bought now. I bought this for the block (Mega block), but might use this rotating assembly if it can be repaired.
Thanks, Brian

Re: Crankshaft repair?? [Re: '72CudaRacer] #2741373
02/09/20 08:52 PM
02/09/20 08:52 PM
Joined: Feb 2005
Posts: 20,116
PA.
pittsburghracer Offline
"Little"John
pittsburghracer  Offline
"Little"John

Joined: Feb 2005
Posts: 20,116
PA.
Lots of good cranks out there for under 1000.00.


1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time




Re: Crankshaft repair?? [Re: '72CudaRacer] #2741411
02/09/20 10:17 PM
02/09/20 10:17 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Posts: 43,007
Bend,OR USA
I've had to have more than one crankshaft thrust surfaces repaired, I use to have them chromed, not now though whiney
Do you have a good shop to fix it? If so ask them to look at it and give you their opinion on fixing it (welding it up) and costs up scope


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Crankshaft repair?? [Re: Cab_Burge] #2741449
02/10/20 12:18 AM
02/10/20 12:18 AM
Joined: Dec 2007
Posts: 12,587
Great Neck,LI,new york
hemi-itis Offline
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hemi-itis  Offline
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Joined: Dec 2007
Posts: 12,587
Great Neck,LI,new york
Do they make an oversized thrust bearing?? work


HEMI-ITIS has no cure.
My condition is fully BLOWN!!
Re: Crankshaft repair?? [Re: hemi-itis] #2741466
02/10/20 02:46 AM
02/10/20 02:46 AM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Posts: 43,007
Bend,OR USA
Maybe years ago, none now that I know of.
Back before anti ballooning plates where added into converters it was not uncommon to loose the thrust surfaces on the bearings and crankshafts whiney


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Crankshaft repair?? [Re: Cab_Burge] #2741484
02/10/20 09:35 AM
02/10/20 09:35 AM
Joined: Jan 2003
Posts: 13,319
Marion, South Carolina [><]
an8sec70cuda Offline
I Live Here
an8sec70cuda  Offline
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Joined: Jan 2003
Posts: 13,319
Marion, South Carolina [><]
I've had a couple of cranks repaired by welding up the thrust surface and turning them back down and not had a problem. Not a big deal...local performance machine shop does it for me. Much cheaper than a new crank.


CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
Re: Crankshaft repair?? [Re: an8sec70cuda] #2741492
02/10/20 10:08 AM
02/10/20 10:08 AM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
I had it done before...they weld it up with a process called spray transfer then turn the crank to the finished spec
wave

Re: Crankshaft repair?? [Re: MR_P_BODY] #2741646
02/10/20 05:19 PM
02/10/20 05:19 PM
Joined: May 2003
Posts: 6,545
Downtown Roebuck Ont
Twostick Offline
Still wishing...
Twostick  Offline
Still wishing...

Joined: May 2003
Posts: 6,545
Downtown Roebuck Ont
If you use the crank again check the converter/crank register for clearance. I've seen the thrust wiped out on a 4.15 stroke Hemi that they used a 6 bolt crank in with a stock Hemi converter. When the customer installed it the converter wouldn't touch the flex plate but he could still get the bolts started. A little brute force and she fit...

Fortunately it didn't hurt the crank, just the bearing.

We were told a stock Hemi crank register is bigger than an RB because a stock Hemi converter snout is bigger. Don't know if it's true or not but the new converter didn't interfere with the register and the old one did.

Kevin

Re: Crankshaft repair?? [Re: Twostick] #2741693
02/10/20 06:43 PM
02/10/20 06:43 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
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Joined: Aug 2003
Posts: 43,007
Bend,OR USA
Me thinks that 6 bolt stroker crankshaft had issues on the wrong converter I.D. on the crank hub twocents
As far as I know Mopar has two different converter hub O.D. sizes, 727 and 904 size hubs scope

Last edited by Cab_Burge; 02/10/20 06:44 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Crankshaft repair?? [Re: Cab_Burge] #2741715
02/10/20 07:35 PM
02/10/20 07:35 PM
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
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fast68plymouth Offline
I Live Here
fast68plymouth  Offline
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Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
Call Shaft Tech for a price to repair it if you can’t get it done locally.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Crankshaft repair?? [Re: fast68plymouth] #2741806
02/11/20 01:38 AM
02/11/20 01:38 AM
Joined: Jan 2003
Posts: 3,830
N.E. Ohio
6bblFLASH Offline
master
6bblFLASH  Offline
master

Joined: Jan 2003
Posts: 3,830
N.E. Ohio
Originally Posted by fast68plymouth
Call Shaft Tech for a price to repair it if you can’t get it done locally.



That's who did mine.
Absolutely no evidence of a repair..PERFECT!!
However it was expensive, 700 bucks for thrust repair.


70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!
Re: Crankshaft repair?? [Re: 6bblFLASH] #2741813
02/11/20 04:20 AM
02/11/20 04:20 AM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
I Win
Cab_Burge  Offline
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Joined: Aug 2003
Posts: 43,007
Bend,OR USA
Originally Posted by 6bblFLASH
Originally Posted by fast68plymouth
Call Shaft Tech for a price to repair it if you can’t get it done locally.



That's who did mine.
Absolutely no evidence of a repair..PERFECT!!
However it was expensive, 700 bucks for thrust repair.

Sounds like they really don't want to repair crankshafts to me shruggy


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)






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