Back too high...

[Jean-Pierre]

Hi guys,


Well, I just arrived and introduced myself that I already have a question: I find that my fastback has the back too high.

Other guys have noticed it too. I know that the leaf springs have been changed before I buy it and maybe that's why. 

The rear suspension is hard too. I found a picture of the car of 2010. Next to a photo of 2018, we see the difference. 

I looked under the car but I do not see anything wrong. 

Do you have an idea?...




 










 

 

[Jean-Pierre]

Another...

 

[Hemikiller]

First thing would be to remove the overload shocks. Those were a popular item to raise the rear of sagging leaf spring cars.

Second is it looks like your springs have been replaced with a "high lift" type spring. The non OEM style square cut edges of the leafs is a clue. Also looks like they never bothered to remove the packing slip off the driver's leaf spring.

Also, what size tires are you running? They look awful small to me. Factory tires were in the 25.5" ~ 26" diameter range.

 

[Stanglover]

I can't see from the pictures, but longer rear shackles were a popular add-on to raise the back end. The 72 I had had these, but were very obvious. However, rethinking this, I agree with Hemikiller, those shocks are the most likely cause as everything else looks pretty stock.

Also on my current 71, I replaced the rear springs with standard eye 4.5 leaf aftermarket ones and found they were 1.5" higher than the old worn out ones I took off. My solution was to put 1" lowering blocks until the springs settle, which could take some time. Done correctly with longer and stronger U bolts, I have zero negative handling issues and the car looks 'right' again. I could have chosen springs with a different eye configuration to achieve the same thing...……. until they settle, then the backend might be too low.

Geoff.

 

[c9zx]

The car sits too high in the front as well. It seems the previous owner installed the wrong springs, front and rear. The correct springs can be purchased from Eaton Detroit Springs. Chuck

 

[Don C]

I agree, get rid of the shocks, good starting point. From what I can see in the picture, it looks like aftermarket adjustable spring shackles, too. Make sure they're in the bolt holes that lowers the rear as much as possible.

Is there anything in the front springs? Twist in spring adjusters that raised the front used to be popular for sagging coil springs.

 

[Stanglover]

The car sits too high in the front as well. It seems the previous owner installed the wrong springs, front and rear. The correct springs can be purchased from Eaton Detroit Springs. Chuck

 Wrong front springs! Too easily done if one buys aftermarket "kits" as I did. The kit I bought was a frakin Scott Drake abortion. The front springs they included for a 71 Mach 1, were a, the wrong height, b, the wrong gauge steel and c, the wrong spring rate for MY car. The front sat 2.5 " higher than it should have. ( and they get away with selling this junk!!)

I sent them back for a refund and after a complete inspection, I reinstalled the original Eaton Springs ones as they were still perfectly in spec.

I totally agree with you Chuck, spend a few extra bucks and buy Eaton Springs. If you call them (or email) they will spec the exact springs for your  car.

 

[Stanglover]

Another...

Hate to be too critical, but did you know your car is not a Mach 1? No staggered rear shocks, but that's ok too as it looks the part and most will never know.

 

[mudbilly]

Back in 73 that car would have been sitting just perfect jacked up like that where I grew up.........

 

[donkost]

Back in 73 that car would have been sitting just perfect jacked up like that where I grew up.........

You got that right, same here.  lol  It would have had aluminum slots and N50's on the back though.  In the before picture we see the Mustang script on the front fender, and it is of course personal preference to run with the Mach 1 decal in the recent pic.  I do believe though that the Mach 1 with the base 302 would not have had the competition suspension with the staggered shocks.  I'm at the point where I don't get overly critical with the choices on certain cars, because in many cases people bought them that way and perhaps haven't had time or money to remove non-stock features.  Or they like them that way, it's all good as long as someone isn't trying to pass off a tribute type of car for big bucks.  It's more important now to just keep these cars on the road rather than rusting in a junkyard. ::thumb::

 

[NOT A T5]

Nothing wrong with the rear being up like that but the front needs to be lower in my opinion to give it a little rake! Back in the day I cut my front springs 1 full turn, couldn't even get a jack under the front  :whistling:

 

[Jean-Pierre]

Ok guys,

Thank you for all your answers that help me a lot.

First, for a simple start, I ordered 1" lowering blocks.

Then, you tell me to remove the overload shocks. Ok but what can i put in the place? size, diameter?

I'm not bad in méchanics but not enough in shock absorbers.

There are too many choices...

https://www.eatondetroitspring.com/db/es-partsinquiry2.php?syear=1973&smake=Ford&smodel=Mustang&sbody=Fastback&seng=V8%205.8L%20-%20351%202bbl

I don't think that the rear shackles are longers but I would check.

My tyres are 215/75x14 and indeed, I find them too small.

 

[Jean-Pierre]

And what do you think about adjustable overload shocks like that...

 

[luxstang]

As for shock absorbers I always recommend KYB shocks. Really great quality at an affordable price. I’ve used them extensively and I love them!

 

[Jean-Pierre]

I thought adjustable because even if they are a little more expensive, I can adapt the ride height to my liking...

 

[Hemikiller]

Hate to be too critical, but did you know your car is not a Mach 1? No staggered rear shocks, but that's ok too as it looks the part and most will never know.

Not all Machs came with staggered rear shocks, only the 4V 351 & all 429 cars. 2V 351 (H) and 302 (F) didn't get them.

 

[timachone]

+1 on Luxstang, can recommend KYB-shocks, best price-worth-ratio - will them buy, too and get rid of the old hi-jackers...

Be aware that hi-jackers and other, similar shock constructions can affect your upper mounting spots in a bad way...

 

[c9zx]

There is no good reason to have overload shocks on your mustang. The shock mounting points are designed to accept a shock absorber not an additional spring. The upper mounting socket is just sheet metal. For the money the KYB shocks are a good value and work well. Does the previous owner still have the original springs? Chuck

 

[Jean-Pierre]

Ok guys, finally I understand what you say (whaooo, my english is reallly bad)

I leave only the shock absorber in place or I change for that : 



And I remove the springs, that's right ?...