Front Suspension Bang

[raeovine]

Hello everyone.  I recently replaced the entire front suspension on my mach 1.  This included upper/lower control arms, sway bar, strut rods, tie rods, shocks etc.  The kit is in and every time I go over a bump I hear a banging from the front.  Being new to this, I had difficulty getting the springs out/in.  Because of this, I eventually cut approximately three inches of coil from the bottom of the spring (not 3" of total height, coil length).  Based on viewing, the tires seem lower in the wheel well and when I look at the shocks, I am thinking the shocks are bottoming out because the ride is too low.  I've included pictures of the shocks to show how far they extend in the tower.  Also, the top bushing of the shocks got totally destroyed.  Not sure if that is related or another problem I haven't even discovered yet.

I'd love someone to tell me how dumb I was and I need to replace those cut spring with new, full length ones.  I just want to confirm a direction before I throw more money and effort at it.  The springs were a beast for me to do so I only want to fight them again if absolutely necessary.

I'd be happy to take more pictures if that helps!  Thank you all in advance

 

[Don C]

If you don't use a proper spring compressor you'll have problems with the springs, that's for sure. Here's a link

https://dazecars.com/dazed/spring.html

I don't think cutting 3" off the coils will cause your problem. It's likely the top of your shocks banging around causing the noise. It's been discussed before

https://www.7173mustangs.com/thread-front-shock-bushings?

 

[Hemikiller]

Agree with Don, replace the bushings with urethane parts from Energy Suspension. Also, make sure you have the bumpers on the outer shock tower.

 

[raeovine]

Thank you both for your quick replies. I do have the bumpers on the shock tower covers and agree that the sound seems like the shock is bottoming out. I used an internal claw type spring compressor to remove and install the springs. I did not read how the type of compressor can compromise the spring. Based on the pictures, is the spacing and such look correct. I took the shock out and lowered it on the springs only. Then I put the shock back in. I don’t see much clearance between the top of the shock and the top of the tower. I assume the spring is what is causing it but agree that only 3” shouldn’t cause this.

I can definitely add poly bushings to the shock but am not sure that will fix the problem of the bang.

 

[7173Vert]

I’m not convinced those are the correct front shocks based on the pics. What model and part # are these?

 

[raeovine]

I bought them from CJ pony parts. Site said they fit 1973 mustangs.

https://www.cjponyparts.com/scott-drake-performance-shock-front-1971-1973/p/FSHOCK2/

They matched in size the ones I took out. I was thinking the same though based on fitment.

 

[Bill73Ragtop]

Summit Prothane upper shock mount bushings: https://www.summitracing.com/parts/ptp-19-901-bl/overview/

On the other hand, you are using Scott Drake shocks....there have been reported issues with some Scott Drake products.

 

[Carolina_Mountain_Mustangs]

Taking the springs out with proper tool should not be a huge issue. Just some wrench time. Seems like you have to compress them about 4" to get them out.

On the shock bushings  everyone blames them tearing on sorry rubber. The biggest issue is that in the Ford manual they tell you not to lift the car and let the front wheels hang. Ford had a special tool to block the upper control arm from going all the way down and putting the full pressure of the coil spring on the rubber bushing.

The rubber is to isolate the shock not support the full pressure of the coil spring. It will crush it every time you lift the car. A simple block of wood between the upper control arm and the frame rail will stop the damage. Or you can make a pair of the tools.

Not blocking the suspension travel can also split the radius rod bushings in the front cross member.

You should be able to remove and replace every part on your Mustang and not be difficult. If it is wrong tool or wrong process.

special_Tool_Mustang.docx

 

[71fast]

I bought them from CJ pony parts. Site said they fit 1973 mustangs.

https://www.cjponyparts.com/scott-drake-performance-shock-front-1971-1973/p/FSHOCK2/

They matched in size the ones I took out. I was thinking the same though based on fitment.

The shocks listed are for the rear

 

[raeovine]

David is right. The shock bushings are damaged because I lifted the car without bracing the control arm. Mistake on my end. I’m still not 100% convinced that the little amount (at least in my inexperienced mind) that I removed from the spring would cause such a noise but I will gladly try new springs and get them In without removing any length of them. Could there be any other causes I should investigate? I very much appreciate all the input from the group. It has been very helpful.

Could I have done something really dumb like install the sway bar upside down or something? I don’t think so but I wouldn’t put it past me.

 

[Carolina_Mountain_Mustangs]

I do not thing the cut off spring would make it bump but never know. How the spring sits in the pockets would be changed if you cut them for sure.

I just had sway bar off one of mine to replace bushings and I do not think you can put on upside down?

If you change the springs again get a good compressor. Most of the auto parts stores rent them for free so you do not have to purchase one. A little grease on the screw threads helps a lot.

When you are taking the compressor off the spring I always lay a piece of plywood on the spring laying on the ground so if the fingers happen to slip on the spring it will not kill me. The amount of energy stored in the spring when compressed is a lethal weapon. Just be safe and it will be ok.

You should be able to compress the new spring and just sit in place and back off on the compressor with no problem.

 

[Hemikiller]

I doubt you can install the sway bar upside down, but if the end links are too long, it could hit the frame.

The Dorman description on Rock Auto shows the sleeve as 2 1/2" long.

https://www.rockauto.com/en/moreinfo.php?pk=8911144&cc=1132692&jsn=14

 

[raeovine]

I did double check the sway bar and it appears to be installed correctly. End link length is a match based on hemikiller’s measurements. New springs arrived from Rock Auto this weekend. Insulators arrive today and I have replacement bushings for the shocks. Hope to have a successful update for the group later in the week!

 

[raeovine]

I got everything installed and the suspension is much better than before. Ride height in the front has increased and the shock sits at the right height in the tower. Overall I believe the cut spring caused the problem! Thanks to all for helping me through the problem. Now I can enjoy driving it this summer

 

[Carolina_Mountain_Mustangs]

:bravo: Glad it all worked out.