Okay. I didn't think that would be a good idea. When I get s chance I try the left side and see what happens. She feels great though'. Really rides smooth very impressed!
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Shelby drop and lowering spring
- Thread starter 67stang
- Start date
Okay. I didn't think that would be a good idea. When I get s chance I try the left side and see what happens. She feels great though'. Really rides smooth very impressed!
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Hey everyone. Thank you again for all the tips!! And help. A friend of mine also has a 67 fastback and was wondering about if a 4 link rear suspension would help from the car going. He has a mustang 2 front suspension and standard air shocks in the rear with original leaf springs. He says when he is going above 50mph over small rises in the road and as the car settles back down it will sway left to right. Would a 4 link rear suspension stop this? Or this this just the charastics of a 67 fastback?
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Air shocks do not belong on a mustang. The metal at the top mounting hole is not strong enough and will tear eventually. That swaying is almost assuredly also do to the air shocks.
A 4 link is designed to control rotation of the rearend under acceleration and maintain drive angle, etc. Leaf spring will "wrap-up" (twist like a "s") under hard launch which causes loss of energy to propel the car forward. A 4-link has nothing to do with the "swaying" he is experiencing as this is the body moving on the suspension. A proper set of correctly designed shocks is what he needs. And maybe a new set of leaf springs if his are original and VERY old. Not likely he needs more than good shocks.
A 4 link is designed to control rotation of the rearend under acceleration and maintain drive angle, etc. Leaf spring will "wrap-up" (twist like a "s") under hard launch which causes loss of energy to propel the car forward. A 4-link has nothing to do with the "swaying" he is experiencing as this is the body moving on the suspension. A proper set of correctly designed shocks is what he needs. And maybe a new set of leaf springs if his are original and VERY old. Not likely he needs more than good shocks.
Grabber70Mach
Well-Known Member
Agree with Terry on his analysis and give a big second to the No Air Shocks statement.
Also wondering if he may be experiencing bumpsteer issues.
Also wondering if he may be experiencing bumpsteer issues.
I think someone mentioned bilistein shocks are good. Any specific model?
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JeffTepper
Well-Known Member
There are several posts in this thread (I just read this for the first time now) that cause me concern.
First, the pics of your car depict Coy's C67 wheels which, if I am not mistaken, are 17" x 8" with 4.75" backspacing. If they are indeed that configuration, there should be no reason correct factory upper control arms and ball joints would come close to making contact with the wheel rim and no reason for wheel spacers. The fact that this appears to be a real concern leads me to question what upper control arms and ball joints were on the car before you tackled your front end project?
Second, shims on the upper control arm mounting studs are found on pre '67 Mustangs. They should not be needed or used on the '67 for alignment purposes. Their presence on your car raises red flags for me.
Third, the difficulty in getting the correct lower control arm installed on one side should not be an issue unless the frame components are damaged.
For these reasons, I would suspect the car was smacked hard enough to damage the front frame and suspension at some point and whoever repaired it cut corners and used incorrect parts to get everything to "fit". I suggest that a close inspection with a tape measure and the frame alignment specs drawing would be a prudent step to confirm that all front suspension attachment points and the shock towers are within spec.
As far as the 4 link and other high end "solutions" to the ass-wiggle issue your friend is experiencing, I suggest that before he throws parts/money at the problem, a thorough inspection of what he has would be appropriate. For example, the rubber bushings at the front end of the leaf spring wear out over time that may result in too much play in the front mounts. Another example is the rear leaf spring shackles and shackle bushings. Again same issue on the bushings. On the shackles, some aftermarket extended shackles intended to compensate for sagging rear leaf springs can twist when torque is applied resulting in a side to side wiggle.
There is no such thing as "Standard" air shocks for '67 Mustangs. The rear upper shock mounts are a thin piece of sheetmetal not designed to carry the weight of the rear end of the car. In some cases the sheet metal flexes to the point that it tears rendering the upper mount unstable. Last but not least, sloppy or short cut repairs to the rear frame rails in the past may have loaded or unloaded one side of the car creating an unstable platform. Unless the car will be seeing track time, the cost/benefit ratio for a 4 link is hard to justify for many folks. Tape measure and frame alignment spec drawing might be helpful in determining if this is an issue for your friend. Putting the car on a frame alignment rack would allow both front and rear structural alignment to be determined. At that point the problem(s) are identified and repairs and upgrades would be easier to determine.
First, the pics of your car depict Coy's C67 wheels which, if I am not mistaken, are 17" x 8" with 4.75" backspacing. If they are indeed that configuration, there should be no reason correct factory upper control arms and ball joints would come close to making contact with the wheel rim and no reason for wheel spacers. The fact that this appears to be a real concern leads me to question what upper control arms and ball joints were on the car before you tackled your front end project?
Second, shims on the upper control arm mounting studs are found on pre '67 Mustangs. They should not be needed or used on the '67 for alignment purposes. Their presence on your car raises red flags for me.
Third, the difficulty in getting the correct lower control arm installed on one side should not be an issue unless the frame components are damaged.
For these reasons, I would suspect the car was smacked hard enough to damage the front frame and suspension at some point and whoever repaired it cut corners and used incorrect parts to get everything to "fit". I suggest that a close inspection with a tape measure and the frame alignment specs drawing would be a prudent step to confirm that all front suspension attachment points and the shock towers are within spec.
As far as the 4 link and other high end "solutions" to the ass-wiggle issue your friend is experiencing, I suggest that before he throws parts/money at the problem, a thorough inspection of what he has would be appropriate. For example, the rubber bushings at the front end of the leaf spring wear out over time that may result in too much play in the front mounts. Another example is the rear leaf spring shackles and shackle bushings. Again same issue on the bushings. On the shackles, some aftermarket extended shackles intended to compensate for sagging rear leaf springs can twist when torque is applied resulting in a side to side wiggle.
There is no such thing as "Standard" air shocks for '67 Mustangs. The rear upper shock mounts are a thin piece of sheetmetal not designed to carry the weight of the rear end of the car. In some cases the sheet metal flexes to the point that it tears rendering the upper mount unstable. Last but not least, sloppy or short cut repairs to the rear frame rails in the past may have loaded or unloaded one side of the car creating an unstable platform. Unless the car will be seeing track time, the cost/benefit ratio for a 4 link is hard to justify for many folks. Tape measure and frame alignment spec drawing might be helpful in determining if this is an issue for your friend. Putting the car on a frame alignment rack would allow both front and rear structural alignment to be determined. At that point the problem(s) are identified and repairs and upgrades would be easier to determine.
Holy smokes Jeff: the front end now seems awesome. I didn't check any frame alignments. But the wheel alignment was easy to set up and I did remove all the wheel spacers and shims. I did the string method as well to check the rear to the front before I did the toe in and all was square.
It's been running great and feels awesome with no uneven tire wear. Yes the bottom of the car where the lower control arms fits into looks like it was smacked at one point but I was able to get the new lower control arms in eventually. Once they were in place they were snug but night tight.
Just curious why does it really matter if the shock towers and frame are not exactly to new specs? I mean it is a 50 year old car.
The complete bottom sheet metal , engine bay, Dual torque boxes are all new. It has a 351w with a 9 inch rear and the car has little to no rust and drives straight and handles awesome on the road.
Thanks for the advice on my friends 67.
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JeffTepper
Well-Known Member
"Just curious why does it really matter if the shock towers and frame are not exactly to new specs? I mean it is a 50 year old car. "
Given the odd things in your earlier posts about what the PO did, I tend to operate on the premise that if he touched it, he likely screwed it up. Remember that "exact new specs" was far less precise 50 years ago than modern assembly methods allow, so if something if out of spec, it is likely REALLY out of spec! Glad to hear that it seems to be running straight and true now. Get out there and enjoy your car every chance you get!
Given the odd things in your earlier posts about what the PO did, I tend to operate on the premise that if he touched it, he likely screwed it up. Remember that "exact new specs" was far less precise 50 years ago than modern assembly methods allow, so if something if out of spec, it is likely REALLY out of spec! Glad to hear that it seems to be running straight and true now. Get out there and enjoy your car every chance you get!
Curious: now I'm thinking about new leaf springs. I assuming I have original and I do not want the rear end any higher then it is already. In fact I wouldn't mind if it was lowered (at most an inch). Would it be better to go mid eye or reverse eye? To have an even lowered stance. Any pros and cons between mid and reverse eye.
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First off, "struts" on these cars refers to the strut rods of the front suspension. You are referring to shocks, I presume. Modern cars use struts which are a completely different design of spring/shock combination set-up. Just wanted to clarify to avoid confusion. Our cars have springs (coil in front/leaf in back) and shocks at all four corners.
Most guys have used mid-eye springs to lower their cars. Myself included. I don't know how the Drake springs get the lowered effect whether it is flatter spring or modified mounting height like the mid-eyes. The two different approaches will likely provide different ride performance/feel. Not saying either is better or worse because I haven't the means to compare. My guess would be a flatter spring would provide a harsher feel. Just be aware that with any new spring it will need to settle to its final ride height. Some do so quickly and others may take a bit of driving.
Most guys have used mid-eye springs to lower their cars. Myself included. I don't know how the Drake springs get the lowered effect whether it is flatter spring or modified mounting height like the mid-eyes. The two different approaches will likely provide different ride performance/feel. Not saying either is better or worse because I haven't the means to compare. My guess would be a flatter spring would provide a harsher feel. Just be aware that with any new spring it will need to settle to its final ride height. Some do so quickly and others may take a bit of driving.
You added the pic just as I was typing I guess. Based on it I would think a mid-eye spring would work out just as you want.
Yes, Grab-a-Trak
Give me a day or two. I have it up off the ground on stands right now.
Patrick Stapler
Active Member
I installed Drake Mid-Eye leafs on my '66 GT replacing the OEM GT leafs. I loved the stance with the OEM leafs. I also installed Del-Alum bushings front and rear of the leafs. The SD leafs raised my car almost an inch in the rear. In fact, I ended up having to install 1" blocks on the rear just to get the rockers back level front to rear, which is where I wanted it. Wish I had gone with reverse eye. Don't car for the blocks as they tend to get in the way of adjusting the rear shoes and aren't ideal for track conditions.
Thats what I'm afraid of. I don't want to add lowering blocks. But I defiantly don't want to raise the car. Lol.
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Just to add: so I have been slowly improving the beast and the front is done. So with the rear I have added new shocks only. I don't do a lot of burns outs: number one just causes issues, but number two I have wheel bounce!! On certain pavements. So would you get leafs or cal tracks first. If I got new leafs then got cal tracs would the cal tracs just stiffen the ride anyways? Meaning do I need to get leafs and cal tracs? Or would new leafs most likely get rid of the wheel bounce. Just seeing if I really need both.
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