Front Suspension drop

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Jan 8, 2023
Messages
12
Reaction score
14
Location
Antioch, TN
My Car
1973 Mustang Convertible 351C 2V
Guys,

Thanks in advance for your input on this. I have a 73 vert that is extremely low in the front. I put 1" Eaton springs drop springs and leafs on the car and the car sits to low. What is weird is that the control arm to bump stop gap is only about 1/4 of an inch, yes 1/4 of an inch. Its got new Q1 single adjustable shocks on it set to level 9. I wouldn't think that a 1" drop in springs wouldn't cause such low tolerance. My 69 mach1 has 5 1/2" distance between the control arm and bump stop. I bought the car used last year. Any where i can look and measure to see what happened? I measured the distance between the pinch welds under the rocker to the ground its it's just over 7". The rear is 8".

Thanks,

Cip
 
Pinch weld to ground - mine measures 7-1/2" just forward of the door/fender line, and 7-3/4" at the front leaf spring eye. Bump stop to UCA is roughly 2".
 
Assuming you got all the parts back together properly, I'd think Eaton made a mistake. Contact them, describe the problem, and send some pictures. They have a good reputation and should be able to help you resolve the problem. Chuck
 
I had a similar experience with springs from Eaton. I asked for a spring to drop my front 1”, the guy helping me took all the details, car year, model, etc….. sent me some springs that were about two inches shorter just sitting on the bench. I expected they were different steel, coil spacing or due to some other technical reason they’d appear that different while on the bench, but still couldn’t justify it in my mind. Called them back the fella I spoke to (maybe Tony?) said they were the right ones.
Installed them and sure enough the car dropped nearly two inches. I’ve heard to expect more sag as the springs adapt to the weight of the car(?) that was too much drop for me. Got no help when I called them back, so I installed a coil spring spacer to bring it up to my desired height.
 
Is the tail of the spring touching the stop on the lower perch?

Any chance someone did the Shelby drop?

Summit sells poly spacers you can add up top to raise it some?

Also, look at your lower arm. Is it parallel to the ground?
 
I had a similar experience with springs from Eaton. I asked for a spring to drop my front 1”, the guy helping me took all the details, car year, model, etc….. sent me some springs that were about two inches shorter just sitting on the bench. I expected they were different steel, coil spacing or due to some other technical reason they’d appear that different while on the bench, but still couldn’t justify it in my mind. Called them back the fella I spoke to (maybe Tony?) said they were the right ones.
Installed them and sure enough the car dropped nearly two inches. I’ve heard to expect more sag as the springs adapt to the weight of the car(?) that was too much drop for me. Got no help when I called them back, so I installed a coil spring spacer to bring it up to my desired height.
Sorry to hear that about Eaton spring and lack of customer support. I guess things have changed for the worse. Chuck
 
I 1st rebuilt this front end using the 1" lowered spring which is also thicker, anyway I ended up adding the 3/8" polyurethane spacer/insulators. Which almost doubles the height let's say 3/4" ht. While I was at it, I added the saddles, that have grease fittings, they are sealed and rotate 360. They are labeled Boss. This seems like the best route short of all out bearing saddles. I needed the height for the slight rub on a hard right down the driveway. I also had an annoying squeak, from the other new saddles. This was pretty easy until the stupid rubber pads kept coming off while I put the spring on. They have lil rubber **** that stick through a hole and don't hold worth a sh!t. I'm adding safety wire to the other side to hold them. Good ol aircraft safety wire pliers n stainless wire will save me 8 cuss words.

Attachments​

  • IMG_4556.JPG
    IMG_4556.JPG
    679 KB · Views: 1
  • IMG_4558.JPG
    IMG_4558.JPG
    1.2 MB · Views: 1
  • IMG_4565.JPG
    IMG_4565.JPG
    1.1 MB · Views: 1
  • IMG_4568.JPG
    IMG_4568.JPG
  • IMG_4553.JPG
I finally nailed the suspension. When I raised the front up w/ the new spacers the rear needed just a little more, so I added the 1 1/2 " shackles (3/4" difference in ht) I used some old shackles, found my stock spacing, grabbed that 1 1/2" hole above it and chopped the rest off. The front end doubles the effect while the rearend gives you 50% of what you space it with. 1 1/2" is 3/4" in ht. It took multiple attempts to get this suspension right. I drove it through some hard corners this evening. It corners great. I have dished wheels "which I wanted personally" and is a no no on these. You can go inward on these another inch w/back spacing. I had my mind set on this old school slot appearance. I had to have that dish on the wheels, so I had to build the suspension @ them. + I have fairly wide tires & it's worth it when cornering. This drives like a lighter/smaller car. It's 1" drop springs in front .720 vs .650 thicker add a 3/8" urethane spacer/insulators. HD saddles w/grease fittings. Rear 5 leaf springs (std eye) with 1 1/2 shackles. This was a year ago. I've driven this 100's of times since and wouldn't change a thing.
 

Attachments

  • IMG_4590.JPG
    IMG_4590.JPG
    1.8 MB
Last edited:
Why are dished wheels a 'no-no'?
 
Why are dished wheels a 'no-no'?
The farther you push the wheels out from center the faster you will rub the fenders when turning.

Radial tires want more caster. Most of us either added shims on the upper an arm or replaced them with ones that have caster built in.

Stock alignment specs were for bias ply tires

Everything is a trade off.
 
The farther you push the wheels out from center the faster you will rub the fenders when turning.

Radial tires want more caster. Most of us either added shims on the upper an arm or replaced them with ones that have caster built in.

Stock alignment specs were for bias ply tires

Everything is a trade off.
Ah, yep, I know what you mean. I always heard that referred to as a deep dish wheel. An aluminum slot of standard width and stockish backspacing were still called dished wheels, as I recall.
 
Why are dished wheels a 'no-no'?
The center part is concaved on the wheel. The wheel protrudes outward from the hub the more dish you have. This wheel at 9 1/2 fits inside the wheel well just 1/4" I wanted to see a dish on the wheel but wanted it reasonably inside the wheel well. The tire has a convex curve, so the tire will go in the wells only couple of inches before they hit. I don't like to butcher the wheel wells especially since I had to remake the ones, they cut out of the GTO I just sold. With the back wheels you can go inward with the back spacing 1 more inch instead of going outward. The front slot wheels also have a slight dish to them and most only have 3 1/2 " back space. new slots can be ordered in 4" B.S. which helps when you are using wider than stock 70 series tires. Bear in mind all slots stick outward like most Mag wheels requiring you to remove all the lugs and replace them with longer ones. If you buy new lugs most come in 3" lengths, I found it easier to cut 1/4" off to make them 2 7/8" so you can fenagle them in without removing or drilling the backing plates.
 

Attachments

  • IMG_9280.JPG
    IMG_9280.JPG
    43.3 KB
I never ran wheels that wide. Mine were 15x7 slots on my 70 fastback. Probably had a standard-ish backspace of 3 3/4" to 4 1/4". Full width of wheel was probably 8". I think I had 235/60/15 tires, so no issues with fenderwell clearance.

The slots I had used the shank type lugs that reach down inside the wheel and probably had more thread engagement than the stock lug nuts.

Running a wider wheel and less backspace would definitely be a reason for longer (safer) wheel studs.

Not enough people running slots these days. A polished set looks so nice with the metallic copper/bronze, golds, greens and blues of that era. Never cared for the two piece chromey Cragar look...too flash. TorqueThrusts, on the other hand...
 
Back
Top