'73 Duster Rear Shocks

[Rodney Barto]

Looking for some advice on my '73 Duster. I'm replacing the rear shocks. The original shocks have a maximum extended length of 23.375" (these seem to match the length: 31131 :: e-Catalog :: MONROE® SHOCKS & STRUTS) and the replacement air shocks I want to use are about 2" shorter with a maximum extended length of 21.250" (These are the replacement shocks: MA704 :: e-Catalog :: MONROE® SHOCKS & STRUTS). With the car off the ground, I can't mount the air shocks without using a jack and lifting the rear end about half an inch. Could this cause issues with the shocks supporting the entire weight of the massive Ford 9 inch rear end I have?

Pic for attention

I can upload additional pictures if that would be beneficial.

 

[72bluNblu]

Looking for some advice on my '73 Duster. I'm replacing the rear shocks. The original shocks have a maximum extended length of 23.375" (these seem to match the length: 31131 :: e-Catalog :: MONROE® SHOCKS & STRUTS) and the replacement air shocks I want to use are about 2" shorter with a maximum extended length of 21.250" (These are the replacement shocks: MA704 :: e-Catalog :: MONROE® SHOCKS & STRUTS). With the car off the ground, I can't mount the air shocks without using a jack and lifting the rear end about half an inch. Could this cause issues with the shocks supporting the entire weight of the massive Ford 9 inch rear end I have?

Pic for attentionView attachment 1715323535

I can upload additional pictures if that would be beneficial.

If the shocks are too short and you unload the rear suspension rapidly you'll overextend them, which could blow the shocks apart. Or rip the mounts off. Or both. Catastrophic failure is probably unlikely, but with them being over 2" shorter you could definitely ruin the shocks.

The other thing is, why do you want air shocks? If the purpose is lifting the car, you'll ruin the shock mounts. The upper shock mounts were not intended to support the weight of the car, just the resistance that comes from the shocks. If you raise the car with the shocks you're putting the weight of the car on the shocks, and the shock mounts will fail eventually. There's a lot of cars out there with screwed up shock mounts because of the whole 70's air shock craze.

If you want to raise the rear of the car, look at getting the rear springs re-arched. Or new springs entirely with a higher arch. Air shocks and extended shackles are band aids, and both will cause damage in the long run to raise the car in the short term.

 

[Rodney Barto]

If the shocks are too short and you unload the rear suspension rapidly you'll overextend them, which could blow the shocks apart. Or rip the mounts off. Or both. Catastrophic failure is probably unlikely, but with them being over 2" shorter you could definitely ruin the shocks.

The other thing is, why do you want air shocks? If the purpose is lifting the car, you'll ruin the shock mounts. The upper shock mounts were not intended to support the weight of the car, just the resistance that comes from the shocks. If you raise the car with the shocks you're putting the weight of the car on the shocks, and the shock mounts will fail eventually. There's a lot of cars out there with screwed up shock mounts because of the whole 70's air shock craze.

If you want to raise the rear of the car, look at getting the rear springs re-arched. Or new springs entirely with a higher arch. Air shocks and extended shackles are band aids, and both will cause damage in the long run to raise the car in the short term.

Those were the failures I was concerned about. Thanks for the confirmation.

The main reason I wanted air shocks was to set one side a little stiffer to compensate for a leaning body due to a weak leaf spring - but you're right, that's just the band-aid way of "fixing" the issue. I needed new shocks anyway and figured I would try to fix two issues at the same time.

I'll probably look into getting a new set of leaf springs with a slightly higher arch. Have any recommendations?

Thanks for the reply and advice!