#1  
Old 07-19-2019, 01:06 PM
alanmay0 alanmay0 is offline
Chief Ponti-yacker
 
Join Date: Nov 2017
Location: Texas
Posts: 612
Default sway bar slide

Hello a few weeks ago I installed a Hotchkis sport suspension sway bar on the back of my 1967 GTO. Today I had it up on the hoist and noticed that the sway bar is sliding from side to side. This is evident by the grease relocation on each side of where the sway bar is attached the the rear axle. Look closely and you can see where it is sliding back and forth. Is this normal?? It seems like I have been experiencing torque steer recently. Could the two be connected somehow? If so How? Three pictures attached.

thank you in advance
alan
Attached Thumbnails
Click image for larger version

Name:	20190719_091508.jpg
Views:	286
Size:	37.1 KB
ID:	516038   Click image for larger version

Name:	20190719_091514.jpg
Views:	263
Size:	35.1 KB
ID:	516039   Click image for larger version

Name:	20190719_091522.jpg
Views:	251
Size:	30.8 KB
ID:	516040  

  #2  
Old 07-19-2019, 01:42 PM
SRR's Avatar
SRR SRR is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: San Diego, California
Posts: 1,225
Default

Might want to give all your rear control arm bushing a close look. That seems to be a lot of movement.

__________________
“Nothing in the world can take the place of persistence. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent. The slogan Press On! has solved and always will solve the problems of the human race.”
― Calvin Coolidge
  #3  
Old 07-19-2019, 02:00 PM
Mike Davis's Avatar
Mike Davis Mike Davis is offline
Ultimate Warrior
 
Join Date: Jun 2000
Location: Athens Ga, or at a NMCA race
Posts: 1,994
Default

Check control arm bushings. If they are good try 4 of these.

https://www.grainger.com/product/29N...g!431367529106!

__________________
66 GTO Nostalgia Super Stock/Street Legal Car
421 CID, stock block, Wenzler Intake, 2- Carter 750 AFB's, 3.90 Gears, Full Factory Interior, Full Exhaust, Stock Suspension 3750LBS 9.77@136.99
Multiple NSCA/NMCA World Champion

66 GTO 389 3x2, 4 speed, 4.33 gear, Montero Red 33K original Miles
67 GTO 2dr Post, 428, Tri Power, 3.55 Gears
80 Trans Am Black SE Y84 W72 WS6
  #4  
Old 07-19-2019, 02:00 PM
JLMounce JLMounce is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: Greeley, Colorado
Posts: 3,679
Send a message via AIM to JLMounce
Default

Think about what is happening to the sway bar, which is rigidly mounted to the frame, when the axle articulates in motion comparatively to the frame. There is going to be some movement of the sway bar at it's connection to the axle.

Now that's not to say the rear bar isn't partly to cause for your new steering issue. You've added more rate to the springs back there when the axle isn't moving directly up and down. On hard acceleration, the pinion gear wants to climb the ring gear, which acts on the axle itself and tends to lift one side. This is why you see drag racers using air bags on one side in the rear.

This motion does transfer to the front of the car where any bump steer issue in the front can come in to play and cause what fwd drivers would call torque steer. The a body suspension does inherently have a good amount of bump steer in it and certain alignment setups can make that worse.

__________________
-Jason
1969 Pontiac Firebird
  #5  
Old 07-19-2019, 02:53 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

CONFUSED, Rear sway bars normally attach to the rear lower control arms and do not need the U shaped Brackets at all on the rear.

The bar if designed right bolts solid to the sides of the control arms.
I have used shims between the lower arms and the outside edge of the sway bar so that the rear bar does not have any side to side movement.

Tom V.

The pictures almost look like you are talking about the front sway bar.

__________________
"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.
  #6  
Old 07-19-2019, 03:10 PM
Mike Davis's Avatar
Mike Davis Mike Davis is offline
Ultimate Warrior
 
Join Date: Jun 2000
Location: Athens Ga, or at a NMCA race
Posts: 1,994
Default

Quote:
Originally Posted by Tom Vaught View Post
CONFUSED, Rear sway bars normally attach to the rear lower control arms and do not need the U shaped Brackets at all on the rear.

The bar if designed right bolts solid to the sides of the control arms.
I have used shims between the lower arms and the outside edge of the sway bar so that the rear bar does not have any side to side movement.

Tom V.

The pictures almost look like you are talking about the front sway bar.
Tom see link below. These are similar to the HR parts n stuff and the BMR. Bolts to axle housing and has brackets that go to the frame or control arms.

https://www.hotchkis.net/product/196...k=&yr=&md=&sm=

__________________
66 GTO Nostalgia Super Stock/Street Legal Car
421 CID, stock block, Wenzler Intake, 2- Carter 750 AFB's, 3.90 Gears, Full Factory Interior, Full Exhaust, Stock Suspension 3750LBS 9.77@136.99
Multiple NSCA/NMCA World Champion

66 GTO 389 3x2, 4 speed, 4.33 gear, Montero Red 33K original Miles
67 GTO 2dr Post, 428, Tri Power, 3.55 Gears
80 Trans Am Black SE Y84 W72 WS6
  #7  
Old 07-19-2019, 03:54 PM
Chris65LeMans's Avatar
Chris65LeMans Chris65LeMans is offline
Ultimate Warrior
 
Join Date: May 2013
Location: Los Angeles, CA
Posts: 1,591
Default

I’d call Hotchkis and ask. Like Tom said, I’ve never seen rear bars that attach that way. Reading the copy in the link, it says “... designed to pivot..” - so that may be what it’s supposed to do?

__________________
1965 Pontiac LeMans. M21, 3.73 in a 12 bolt, Kauffman 461.
  #8  
Old 07-19-2019, 06:22 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

Thanks Mike and Chris, Learned something new about "A-Body" parts today.

I really doubt that you could ever break a HO Racing rear sway bar but whatever.

Thanks again

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.
  #9  
Old 07-19-2019, 11:34 PM
4zpeed's Avatar
4zpeed 4zpeed is offline
Chief Ponti-yacker
 
Join Date: Aug 2017
Location: Hills of WV
Posts: 662
Default

Quote:
Originally Posted by Tom Vaught View Post
Thanks Mike and Chris, Learned something new about "A-Body" parts today.

I really doubt that you could ever break a HO Racing rear sway bar but whatever.

Thanks again

Tom V.
Agreed, could've had something to do with that chatter issue as well.

http://forums.maxperformanceinc.com/...d.php?t=830810


Frank

__________________
Poncho Huggen, Gear Snatchen, Posi Piro.
  #10  
Old 07-19-2019, 11:45 PM
Ducks Goat's Avatar
Ducks Goat Ducks Goat is offline
Chief Ponti-yacker
 
Join Date: May 2005
Location: Gaffney, S.C.
Posts: 635
Default

I had a BMR bar on my '65 and it would move about 1/2' side to side. It never seemed to affect anything negatively that I could tell.

__________________
1999 WS6 Formula, 1 of 175
1967 GTO Linden Green 4 spd, A/C, survivor
1967 Lemans convt
1967 Firebird 400 bench seat, deluxe interior, auto
1965 GTO 462, KRE unported D-port heads, Bullet 234/244 cam, th400, tight 10" converter, 3.73 gears, 87 octane, 3440 lbs. empty,1.59 60ft, 7.159@95.33 (1/8), a real daily driver, been totaled, rolled 3 times, hit a tree airborne.
1961 Catalina 2 door htp
1960 Ventura 4 door htp wife's car
1960 B'ville 2 door htp
1960 Catalina Wagon wife's car too
  #11  
Old 07-20-2019, 12:11 PM
tjs72lemans tjs72lemans is offline
Ultimate Warrior
 
Join Date: Oct 2017
Location: Winona, MN
Posts: 1,157
Default

Makes you question if the rear end has an issue that is causing it to walk around.

  #12  
Old 07-20-2019, 12:19 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

One thing that can cause the rear axle on a "A-Body" to move around is if the upper and lower control arm bushings are shot. Same deal for the upper rear axle housing bushings.

I had bushings made from Bullit-proof Plexiglas and they will not fail due to impact or deform over time. They are a bit stiffer vs the Poly stuff though or the Rubber parts.

Tom V.

Ford was throwing out 2" thick sheets of the stuff 24" X 40" long.
When it gets a bit scratched then the cameras installed in the CRASH PIT cannot film the crash properly,
so they scrap the sheet. A sheet costs hundreds of dollars. You do NOT want a Rear Suspension System
with a lot of slop or you will get as was said Chatter.

__________________
"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.

Last edited by Tom Vaught; 07-20-2019 at 12:25 PM.
  #13  
Old 07-20-2019, 10:05 PM
Ducks Goat's Avatar
Ducks Goat Ducks Goat is offline
Chief Ponti-yacker
 
Join Date: May 2005
Location: Gaffney, S.C.
Posts: 635
Default

On my BMR it clamped to the housing then the ends were connected to spherical links attached to the frame. The rear end itself doesn't move around, I think what's happening is if the left corner of the chassis goes down like in a turn it'll push the bar slightly to the right and vice versa. It doesn't move that much but would leave a grease mark on the bar like the OP's. When driving straight it wouldn't move at all side to side.

__________________
1999 WS6 Formula, 1 of 175
1967 GTO Linden Green 4 spd, A/C, survivor
1967 Lemans convt
1967 Firebird 400 bench seat, deluxe interior, auto
1965 GTO 462, KRE unported D-port heads, Bullet 234/244 cam, th400, tight 10" converter, 3.73 gears, 87 octane, 3440 lbs. empty,1.59 60ft, 7.159@95.33 (1/8), a real daily driver, been totaled, rolled 3 times, hit a tree airborne.
1961 Catalina 2 door htp
1960 Ventura 4 door htp wife's car
1960 B'ville 2 door htp
1960 Catalina Wagon wife's car too
  #14  
Old 07-21-2019, 12:28 AM
Schurkey Schurkey is offline
Ultimate Warrior
 
Join Date: Aug 2002
Location: The Seasonally Frozen Wastelands
Posts: 5,891
Default

If this were me--and it isn't--I'd hang the bar from the body/frame above the axle, with links dropping down to the axle or the control arms. This would drop the unsprung weight considerably.

As is...I'll continue with my heavy-ass HO Racing rear bar that stretches from arm to arm like the OEM bar.

  #15  
Old 07-23-2019, 05:54 PM
KEN CROCIE KEN CROCIE is offline
Pontiac Performance Author
 
Join Date: Mar 2000
Location: Rancho Cucamonga Ca.
Posts: 1,522
Default

Check the upper cross member. If not equipped with reinforcement bars, it can flex, crack, or remove itself from the car.

__________________
GOOD IDEAS ARE OFTEN FOUND ABANDONED IN THE DUST OF PROCRASTINATION
  #16  
Old 07-23-2019, 10:04 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

YOU THE MAN MR CROCIE. We have been dancing around that possible torque steer issue and it never entered my mind to ask if he had installed the crossmember reinforcement brackets that GM used after the crossmembers cracked on the early cars.

(And I have installed those brackets on my car.)

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.
  #17  
Old 07-24-2019, 02:11 AM
4zpeed's Avatar
4zpeed 4zpeed is offline
Chief Ponti-yacker
 
Join Date: Aug 2017
Location: Hills of WV
Posts: 662
Default

If you read the thread on chatter you will see "Put it on the lift and try it, this will tell you."

"Please report back", never heard a peep, next thing you see is this thread, lol.



Frank

__________________
Poncho Huggen, Gear Snatchen, Posi Piro.
  #18  
Old 07-24-2019, 06:10 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,555
Default

Quote:
Originally Posted by alanmay0 View Post
Hello a few weeks ago I installed a Hotchkis sport suspension sway bar on the back of my 1967 GTO. Today I had it up on the hoist and noticed that the sway bar is sliding from side to side. This is evident by the grease relocation on each side of where the sway bar is attached the the rear axle. Look closely and you can see where it is sliding back and forth. Is this normal?? It seems like I have been experiencing torque steer recently. Could the two be connected somehow? If so How? Three pictures attached.

thank you in advance
alan
Is that the bar that bolts to the rear trailing arms or the frame?.....if it’s bolted too the arms I would bet some movement .....definitely take a gander at the uppers to make sure they are intact!

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
  #19  
Old 07-24-2019, 06:17 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

Quote:
Originally Posted by mchell View Post
Is that the bar that bolts to the rear trailing arms or the frame?.....if it’s bolted too the arms I would bet some movement .....definitely take a gander at the uppers to make sure they are intact!
AGREE WITH WHAT YOU ARE SAYING, TO CLARIFY FOR YOU:

He is a not using a GM sway bar mount system (where the bar mounts to the lower control arms).
The Sway Bar has heim lengths from the ends of the sway bar to the rear axle.

BAR DOES NOT MOUNT TO THE LOWER CONTROL ARMS.

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.
  #20  
Old 07-24-2019, 07:45 PM
mchell's Avatar
mchell mchell is offline
Ultimate Warrior
 
Join Date: Jul 2003
Location: North Port, FL
Posts: 2,555
Default

Hotchkis makes a bar that mounts to the axle housing with end links that bolt to the rear trailing arms.......see link below.... can’t tell in his pick if he’s using this particular one, but it looked like it.... looked at them a few time myself

https://www.hotchkis.net/product/196...&md=1089&sm=20

Some other brands of anti roll systems mount the bar to the axle and the end links attach to the frame .....bmr, hr parts etc...

__________________
71 GTO, 463, KRE 295 cfm heads ported by SD Performance, RPM intake, Qjet, Dougs Headers, Comp cams HR 246/252 ...11 to 1 , 3.55 cogs, 3985lbs.....day three- 11.04 at 120mph ....1.53 60', 6.98 1/8 mile
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 01:18 PM.

 

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