Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck
Sponsored by:
Sponsored by: Moser

How do you crack an input shaft?!

Thread Tools
 
Search this Thread
 
Old Sep 19, 2005 | 11:42 AM
  #1  
Oleblue74's Avatar
Oleblue74
Thread Starter
|
New User
Joined: May 2005
Posts: 23
Likes: 0
How do you crack an input shaft?!

We pulled the tranny out of my girlfriends truck this weekend ('74 F250), and after looking the tranny over, I pulled the input shaft out and it has one large crack down the middle and smaller pitts around the shaft, as well as, rings wore into the shaft from wear and worn bearings. The tranny is a C-6 supposidly out of an LTD or some sort of car. They put this in 4 years ago when swapping a 460 in. Of course i'm changing it to a truck C-6 and factory 460 install parts. But what would crack that shaft? She had a problem with the fellas putting the motor in before causing a bind between the motor and tranny. This was because of an aftermarket flexplate and stall converter. Would that cause it or torque of a previous engine? It also has a cracked off mount on the bottom of the tailshaft where the car mount would bolt to. Any ideas?
 
Reply
Old Sep 19, 2005 | 12:22 PM
  #2  
Djoffroad's Avatar
Djoffroad
Senior User
Joined: Mar 2002
Posts: 150
Likes: 0
From: Rancho Cordova, CA USA
I'd like to know myself. I've cracked 2 input shafts on an NP435.
 
Reply
Old Sep 19, 2005 | 01:01 PM
  #3  
monsterbaby's Avatar
monsterbaby
Hotshot
Joined: Dec 2003
Posts: 18,423
Likes: 9
From: iowa
what cracks input shafts on C6s usually some idiot using a hammer on it (I am not kidding either) look at the ends and see if it looks like it was used for a punch or damaged.
np 435s have always had some problems with snapping input shafts when used in jerking heavy loads from a stop, like jerking a loaded wagon full of grain out of a field almost always when used behind the 390s or a 460 but I have seen 360s 300i6s, and some small blocks do it too.
 
Reply
Old Sep 19, 2005 | 10:46 PM
  #4  
witdog2020's Avatar
witdog2020
Senior User
Joined: Sep 2005
Posts: 214
Likes: 0
excess vibration

Excess vibration is the leading cause,usually caused by busted snapring on the input.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
slider6075
Clutch, Transmission, Differential, Axle & Transfer Case
14
Oct 23, 2012 09:27 PM
unioncreek
Clutch, Transmission, Differential, Axle & Transfer Case
3
Jan 1, 2002 05:30 PM
Fordzzzz77
1973 - 1979 F-100 & Larger F-Series Trucks
12
Apr 10, 2000 06:11 AM




All times are GMT -5. The time now is 04:05 PM.

story-0
10 Ways Ford is LOSING to the Competition

Slideshow: 10 ways Ford is losing to the competition

By Joe Kucinski | 2026-06-15 09:52:01


VIEW MORE
story-1
Top 6 Best Deals Available on New Fords & Lincolns Right Now

Some great targets in today's expensive world.

By Brett Foote | 2026-06-15 09:35:19


VIEW MORE
story-2
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-3
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-4
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-5
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-6
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-7
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-8
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-9
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE