#1  
Old 01-17-2023, 10:08 PM
grivera's Avatar
grivera grivera is offline
Ultimate Warrior
 
Join Date: Feb 2005
Location: Just south of Baltimore
Posts: 4,343
Default Adjustable Rear Upper Control Arms

My LeMans has what I believe to be a driveline vibration above 2500 rpm and more noticeable when going through the gears. It has a Ford 9” rear and my angles are as follows:

trans output shaft 3.3 degrees down

driveshaft 2 degrees down

Pinion 1 degree down

Are the control arms the same length for 64-67 A bodies? Some of the application charts don’t include 1964, only 65-67

__________________
Will Rivera

'69 Firebird 400/461, JBP 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears
'64 LeMans 400/461, #16 Heads, HR 230/236, TKO600, 9-inch Rear, 3.89 gears
  #2  
Old 01-17-2023, 10:15 PM
b-man's Avatar
b-man b-man is offline
Moderator
 
Join Date: Sep 2002
Location: Sunny So Cal
Posts: 15,699
Default

The upper control arms are the same for 1964 - 1967.

The upper bushings in the 1964 rear end housing are a smaller diameter than 1965 and later but that doesn’t affect the upper control arms. Your Ford 9” won’t have the smaller bushings.

__________________
1964 Tempest Coupe LS3/4L70E/3.42
1964 Le Mans Convertible 421 HO/TH350/2.56
2002 WS6 Convertible LS1/4L60E/3.23
  #3  
Old 01-17-2023, 10:51 PM
Bill Hanlon's Avatar
Bill Hanlon Bill Hanlon is offline
Ultimate Warrior
 
Join Date: Feb 2005
Location: Fredericksburg, TX
Posts: 2,210
Default

Shouldn't the pinion angle be closer to the transmission angle, but up instead of down?

__________________
My Pontiac is a '57 GMC with its original 347" Pontiac V8 and dual-range Hydra-Matic.
  #4  
Old 01-17-2023, 11:09 PM
grivera's Avatar
grivera grivera is offline
Ultimate Warrior
 
Join Date: Feb 2005
Location: Just south of Baltimore
Posts: 4,343
Default

Quote:
Originally Posted by Bill Hanlon View Post
Shouldn't the pinion angle be closer to the transmission angle, but up instead of down?
That’s what I’m interpreting based on what I’ve researched- need longer uppers

__________________
Will Rivera

'69 Firebird 400/461, JBP 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears
'64 LeMans 400/461, #16 Heads, HR 230/236, TKO600, 9-inch Rear, 3.89 gears
  #5  
Old 01-17-2023, 11:13 PM
grivera's Avatar
grivera grivera is offline
Ultimate Warrior
 
Join Date: Feb 2005
Location: Just south of Baltimore
Posts: 4,343
Default

Quote:
Originally Posted by b-man View Post
The upper control arms are the same for 1964 - 1967.

The upper bushings in the 1964 rear end housing are a smaller diameter than 1965 and later but that doesn’t affect the upper control arms. Your Ford 9” won’t have the smaller bushings.
Thank you!

__________________
Will Rivera

'69 Firebird 400/461, JBP 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears
'64 LeMans 400/461, #16 Heads, HR 230/236, TKO600, 9-inch Rear, 3.89 gears
  #6  
Old 01-18-2023, 04:41 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 30,931
Default

Quote:
Originally Posted by Bill Hanlon View Post
Shouldn't the pinion angle be closer to the transmission angle, but up instead of down?
Agree with that. Up on the rear axle pinion.

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward.
  #7  
Old 01-20-2023, 01:27 PM
Singleton's Avatar
Singleton Singleton is offline
Ultimate Warrior
 
Join Date: Apr 2011
Location: coastal Alabama
Posts: 1,004
Default

Grivera, if your numbers are correct, and the angles all slope the same direction, your operating angles are within 0.3 degrees. Rule of thumb is to have operating angles within 0.5 degrees, so you should be ok. If you raise the trans by 0.3 you would have both operating angles at 1 degree. Again, this is if all the angles are sloping down from front to rear.
https://spicerparts.com/en-emea/calc...gle-calculator
Attached Thumbnails
Click image for larger version

Name:	89EB87F1-31F3-48B0-BBD2-C36F95D76F8A.jpg
Views:	28
Size:	45.8 KB
ID:	605606  

__________________

66 GTO, 495, M22, Dana 60 w/4.10
Sold new at Ace Wilson's Royal Pontiac
http://www.youtube.com/watch?v=cUHC-Z8xhtg
  #8  
Old 01-24-2023, 08:33 PM
grivera's Avatar
grivera grivera is offline
Ultimate Warrior
 
Join Date: Feb 2005
Location: Just south of Baltimore
Posts: 4,343
Default

Thanks- that calculator is interesting and confusing. See link below which is indicates that ideally the trans tailshaft and pinion should be at equal but opposing angles - so in my case I used the adjustable a-arms to move the rear up to 3.1 degrees positive - any more and the coil springs rub the shocks. https://youtu.be/SDjBHT5-u_4

__________________
Will Rivera

'69 Firebird 400/461, JBP 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears
'64 LeMans 400/461, #16 Heads, HR 230/236, TKO600, 9-inch Rear, 3.89 gears

Last edited by grivera; 01-24-2023 at 09:02 PM.
  #9  
Old 01-24-2023, 09:22 PM
Singleton's Avatar
Singleton Singleton is offline
Ultimate Warrior
 
Join Date: Apr 2011
Location: coastal Alabama
Posts: 1,004
Default

The “equal bit opposite” gets tossed around a lot and I believe confuses many unnecessarily. Parallel should be used instead. Also confusing is when someone says pinion up, when what they are describing is pinion down, like the guy in the video. In the attached pic below both the trans output shaft and the pinion shaft are sloping down toward the rear of the car, (rear of car, not the rearend). The entire pinion gear is a short shaft, (yoke, shaft,gear), and is sloping down to the rear, looking left to right, just like the trans shaft, parallel. Some would describe that as pinion up, but when calculating driveline angles, or using that spicer calculator, that would be wrong.
Attached Thumbnails
Click image for larger version

Name:	E7283B9E-B0A5-48D5-B327-645BE58EFD29.jpg
Views:	14
Size:	23.2 KB
ID:	605981  

__________________

66 GTO, 495, M22, Dana 60 w/4.10
Sold new at Ace Wilson's Royal Pontiac
http://www.youtube.com/watch?v=cUHC-Z8xhtg
  #10  
Old 01-24-2023, 09:51 PM
grivera's Avatar
grivera grivera is offline
Ultimate Warrior
 
Join Date: Feb 2005
Location: Just south of Baltimore
Posts: 4,343
Default

I think we’re on the same page - before I adjusted the angle, the pinion was “up”, meaning the rear of the differential was facing up but the pinion yoke was facing down. Now, the pinion yoke is close to parallel (3.1 degrees) with the the trans tailshaft - pinion yoke facing up, back of differential facing down. This is clearer with the Tremec app which says to take all measurements from the same side. I didn’t use the app other than instructions because it’s difficult to get a steady reading. I do have a small square digital angle finder with a magnetic base.

__________________
Will Rivera

'69 Firebird 400/461, JBP 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears
'64 LeMans 400/461, #16 Heads, HR 230/236, TKO600, 9-inch Rear, 3.89 gears
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 12:58 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017