Notices
1948 - 1956 F1, F100 & Larger F-Series Trucks Discuss the Fat Fendered and Classic Ford Trucks

new 9" vibrates

Thread Tools
 
Search this Thread
 
Old Aug 20, 2004 | 04:28 PM
  #1  
56extcab's Avatar
56extcab
Thread Starter
|
New User
Joined: Jan 2004
Posts: 12
Likes: 0
From: colorfull Colorado
new 9" vibrates

I just installed a 72 f100 9" and now I have a vibration at 15 to 25 MPH.

I replaced the brakes, wheel bearings, installed a new drive shaft, reversed eye springs, short stacked the springs and installed new shocks.
That about covers how I messed it up, now how do I fix it.
BTW it now has a choppy ride - before it has just hard.

any help will cause great admiration.
 

Last edited by 56extcab; Aug 20, 2004 at 04:40 PM. Reason: sp
Reply
Old Aug 20, 2004 | 04:49 PM
  #2  
Huntsman's Avatar
Huntsman
Posting Guru
Joined: May 2002
Posts: 1,495
Likes: 2
From: Northwest Fl
Do you know the condition of the 9” rear or was it from a recycler? Are you sure you didn't drop a bearing in one of the U-joints?
 
Reply
Old Aug 20, 2004 | 04:52 PM
  #3  
56extcab's Avatar
56extcab
Thread Starter
|
New User
Joined: Jan 2004
Posts: 12
Likes: 0
From: colorfull Colorado
u-joints came with new shaft - should be OK. Trusted driveline shop. The 3rd member checked out OK.
 

Last edited by 56extcab; Aug 20, 2004 at 04:54 PM.
Reply
Old Aug 20, 2004 | 05:01 PM
  #4  
LEckart's Avatar
LEckart
Posting Guru
Joined: Mar 2003
Posts: 1,734
Likes: 2
From: Kansas City area
Did you change the pinion angle on the new rearend compared to where it was set on the original rearend?
 
Reply
Old Aug 20, 2004 | 05:07 PM
  #5  
56extcab's Avatar
56extcab
Thread Starter
|
New User
Joined: Jan 2004
Posts: 12
Likes: 0
From: colorfull Colorado
No not that I know of. the 72 spring mounts were not touched. Could the lowering have changed it.

PS. the front mount is flipped but in the stock location.
 
Reply
Old Aug 20, 2004 | 05:40 PM
  #6  
pcmenten's Avatar
pcmenten
Posting Guru
Joined: Mar 2002
Posts: 2,070
Likes: 2
From: Boise, Idaho
The angle of the driveshaft to the transmission output shaft must be the same as the angle of the driveshaft to the pinion gear shaft of the differential. If they are not the same angle, it will vibrate.

I'll give odds that they're different, and that's what's causing the vibration.
 
Reply
Old Aug 21, 2004 | 02:55 AM
  #7  
4tl8ford's Avatar
4tl8ford
Post Fiend
20 Year Member
Joined: Jun 2001
Posts: 7,493
Likes: 7
From: Erie, pa
Start here:
http://www.clubfte.com/users/jniolon...nephasing.html
 
Reply
Old Aug 21, 2004 | 05:01 PM
  #8  
fatfenders's Avatar
fatfenders
Post Fiend
20 Year Member
Liked
Loved
Community Favorite
Joined: Feb 2001
Posts: 6,328
Likes: 124
From: Iowa
Wheels and tires are known to be good I assume? After you read the article on Niolon's site and verify pinion angle, I would have the driveline shop have a quick look at the driveshaft. I believe you that they are reputable but mistakes can be made of course. I've had a slightly different experience than Paul regarding pinion angles. I accidently installed my 4* spacers in backwards briefly and can't really say I noticed a vibration. I think you can get by with a few degrees sometimes. But you certainly must be pretty close to correct.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-2

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-3

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-6

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Aug 23, 2004 | 09:48 AM
  #9  
56extcab's Avatar
56extcab
Thread Starter
|
New User
Joined: Jan 2004
Posts: 12
Likes: 0
From: colorfull Colorado
Thanks guys. I'll work through the pinion angle thing and get back to you on the results.
 
Reply
Old Aug 26, 2004 | 09:21 AM
  #10  
56extcab's Avatar
56extcab
Thread Starter
|
New User
Joined: Jan 2004
Posts: 12
Likes: 0
From: colorfull Colorado
all is right with the world

Gentlemen

your technical knowlege is surpassed only by your willinness to share.
it now runs as smooth as a baby's butt.
thank you
 
Reply
Old Aug 26, 2004 | 03:39 PM
  #11  
4tl8ford's Avatar
4tl8ford
Post Fiend
20 Year Member
Joined: Jun 2001
Posts: 7,493
Likes: 7
From: Erie, pa
Originally Posted by 56extcab
Gentlemen

your technical knowlege is surpassed only by your willinness to share.
it now runs as smooth as a baby's butt.
thank you

What did ya find? Inquiring minds want to know.
 
Reply
Old Aug 26, 2004 | 04:25 PM
  #12  
56extcab's Avatar
56extcab
Thread Starter
|
New User
Joined: Jan 2004
Posts: 12
Likes: 0
From: colorfull Colorado
I found the transmission shaft sitting at 0 degrees. (90 degrees from level)The differential, however, was setting at 8 degrees. (98 degrees from level) I got a set of 8 degree shims from a 4x4 shop and brought the diff to 0 degrees.
There is about a 3" rise in the drive shaft and that seems to be OK.
Again thanks a bunch.
 

Last edited by 56extcab; Aug 26, 2004 at 04:47 PM.
Reply
Old Aug 27, 2004 | 10:41 PM
  #13  
pcmenten's Avatar
pcmenten
Posting Guru
Joined: Mar 2002
Posts: 2,070
Likes: 2
From: Boise, Idaho
56extcab, Your follow-up is all the thanks we need. Just let us know about your experiences and we all learn the lesson. Thank you.
 
Reply




All times are GMT -5. The time now is 03:19 AM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE