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Help with Rear Suspension

Hey Guys, I've been a long time lurker of the forums and value all of your advice but I have a bit of a situation. I just recently installed the Dynotech Drive Shaft, which works great by the way, and decided to recheck the torque on the bolts that I had installed.

As I'm jack up the car, using the differential with chocks on the front tires the car's rear end wiggles from side to side. Kinda scary but I put my jack stands under the axle as usual and proceed to check the bolts. Drive shaft is fine but on my way out I notice that my panhard brace is diagonal and the panhard bar, which is directly below it, is parallel to the ground. I get out from under the car and my passenger rear suspension is lower than my driver side if that makes any sense. The rear sway bar seems twisted and I would dare say that the spring and damper seem fully extended on the passenger side? I don't know exactly what I broke in this situation.

I'm sorry to ask you guys such a newbie question but I can't seem to find the right info via google, so I turned to you guys for help.
 

pufferfish

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Hard to tell from the pics what is happening.

First thought is a spring broke. Check the non-extended side. A front spring could also be the culprit, which would make the body lean.

If you put it back on the ground, does all 4 corners sit at their normal ride height?

Not sure, but if one of the rear sway bar hangers let go, that might make this happen as well.

Longshot but, if its in gear with the parking brake on, maybe push in the clutch to see if the body levels out. I don't know how this would happen, but the drivetrain could be torqued with the engine on the beginning of a power stroke. I know it sounds weird, but at least it's easy to check?
 
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Larger pictures would help, and I think putting it down on the ground and checking ride height is the first step.
 
Kinda hard to tell for sure from the photos, but it looks like you've got something placed between the jack saddle and the differential housing. Perhaps that's what's contributing to the rocking side-to-side as you jack the car.

Instead, just let the diff housing sit directly on/in the jack saddle. If you position the saddle carefully under the the diff housing it should sit right down in/on it without any interference with the aluminum diff cover. Think you'll find it's much more stable that way.
 
Puffer, I'll check during lunch time to see if my spring are intact on the other three corners. Sway bar end links are intact as well, I checked that this morning. That panhard brace I thought would be more level but it is showing some serious bend underneath the car under load.

I would love to check the ride height but parking lot is uneven and wouldn't help much so during lunch I'll check that too.

Dabossinne, Yeah that's a piece of cardboard from a beer pallet... Just trying to lessen the metal to metal contact, it really should be a wooden block.

Boss Man, I see that bending in the rear sway bar too. I think it's bent partly due to the right side coming down lower which makes it look twisted. Unless you mean that the bending of the sway bar is the cause of the tilt and not just a consequence of it. Would it even be sturdy enough to accomplish that? Stock sway bar btw.

Thank you guys for the suggestions, please keep them coming, I'm still trying to work this all out and I'll report back later today about the things in question.
 
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sadil said:
Larger pictures would help, and I think putting it down on the ground and checking ride height is the first step.

Yep, the car should always be checked at normal ride height with the correct weight in the car. Keep in mind the panhard bar is just another arc, if you take weight off the rear (like you've done) in the pic, then the body will raise and the axle will swing towards the body side bracket. The PHB should always be parallel to the ground at normal ride height, with the rear centered, BTW

I might add , parallel to the axle as well
 

pufferfish

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blacksheep-1 said:
Yep, the car should always be checked at normal ride height with the correct weight in the car. Keep in mind the panhard bar is just another arc, if you take weight off the rear (like you've done) in the pic, then the body will raise and the axle will swing towards the body side bracket. The PHB should always be parallel to the ground at normal ride height, with the rear centered, BTW

I might add , parallel to the axle as well

its not unloaded. the jackstands are under the axle, not the body.

also, the leaning body relative to the axle will cause the sway bar to appear bent...or a bent sway bar could cause the body to lean.
 
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pufferfish said:
its not unloaded. the jackstands are under the axle, not the body.

also, the leaning body relative to the axle will cause the sway bar to appear bent...or a bent sway bar could cause the body to lean.

I beg to disagree, in the pics the rear of the car is raised, depositing several hundred pounds on the front tires from the rear of the car. If you want to do it that way find some (relatively) flat concrete, jack the car up, (on the suspension and as close to the outside of the car as you can, to simulate tire loading)and raise or lower the jack stands using tiles to get the car even. Then measure the height of the car at all four corners.
 
So I checked the ride height, fronts match and so do the rears. I drove it around, only 5 minutes away from work and the car seems fine, even pushed it a bit... legally and hesitantly.

Looked under the car without jacking it up and my lca relocation brackets seem even and the car seems level.

Is it possible for a damper to fully extend and "lock" while I jacked up the car during the drive shaft installation and only just now has settled out?

My knowledge of dampers is very limited so I apologize if that's a no brainer. I haven't jacked it up to see if my brace is still bent or not. Brace not the bar.

Thanks Puffer and Blacksheep for the info. You guys have been great.
 

isrboss

How did you set pinion angle? Which way is the bow, away from rear end, toward rear end, away from ground or toward ground?
 
Used a digital angle finder for that. Tranny flange was at 4.3, Pinion was at 2.3 thus I have the two degrees of offset for the acceleration accounted for. And to be honest I didn't adjust my lower control arms since I haven't lowered the car thus I thought it would be a direct drive shaft swap, but I checked it just in case upon install. Great question btw.

And the bow? If you are referring to the bow in the brace it would be bending up, away from the ground. Ha, going to sound like a retard if that wasn't your actual question.
 

isrboss

El Jefe 302 said:
Used a digital angle finder for that. Tranny flange was at 4.3, Pinion was at 2.3 thus I have the two degrees of offset for the acceleration accounted for. And to be honest I didn't adjust my lower control arms since I haven't lowered the car thus I thought it would be a direct drive shaft swap, but I checked it just in case upon install. Great question btw.

And the bow? If you are referring to the bow in the brace it would be bending up, away from the ground. Ha, going to sound like a retard if that wasn't your actual question.
I was referring to this comment, but you called it a bend. So the panhard is bowing/bending away from the ground in the center area of the bar? If this is the case, did you have the rear loaded prior to torquing the panhard?
That panhard brace I thought would be more level but it is showing some serious bend underneath the car under load.
 
Yes sir, I had jack stands underneath the axle when I swapped out the panhard brace and the bar when I installed them. I felt it would be best to have the car underload when I did this.

I always thought the panhard brace should be parallel with the car while the panhard bar takes on more a diagonal set up? I'm not trying to start a debate and like I said I don't claim to be an expert on the subject.

If I were to take these items out and reinstall them would it reset the suspension or not do anything?
 

isrboss

Sounds to me like we are confusing bend with angle. Maybe go to a dealership and get under a Mustang and take a look. Better yet if service has one on a lift. The panhard and panhard brace have there own angle if I remember correctly.
 
Yeah I think I will. I'm going to see if reinstalling these things will help out, and center the panhard bar again just to ensure everything is where it needs to be. I tried googling the bar and brace diagrams and didn't come to a decided conclusion so I'll just check it out at the dealership.

Thanks isrboss, hopefully once I do this tonight it'll start looking right. Even checked the front and rear mounts and everything looks good. Stumped but this is another excuse to work on the car.
 

pufferfish

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El Jefe 302 said:
I always thought the panhard brace should be parallel with the car while the panhard bar takes on more a diagonal set up? I'm not trying to start a debate and like I said I don't claim to be an expert on the subject.

the panhard bar should be positioned as close to parallel as possible with the suspension loaded and at rest. I go with a slightly downward angle (axle mount end lower) to account for passengers, since the suspension will be compressed more with people in it...even if its just the driver most of the time.
 
Yeah that makes a lot of sense, however I don't understand what you mean by changing the angle. I thought an adjustable panhard bar only has 1 location spot and by adjusting it you are aligning the outside of your wheels to your fenders?
 

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