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View Full Version : Air Shocks vs Extra Leaf



Kato
03-14-2016, 09:05 PM
I know this has been discussed here before but the car is coming out of storage soon and I must decide which way to go. My 62GT has a tire rubbing issue when the car is loaded. The real issue is likely that the rims are not the ideal offset but I like them and want to keep them. I have 205/75s on the rear so there's not much to be done with tire size. When I drive the car alone or even with my wife there is rarely an issue unless on a very rough road. The problem arises when I put anyone in the back seat or if I were to load the trunk with luggage I would think, I then get quite a bit of rubbing while accelerating, going up a hill or with any uneven road at all.

I am trying to decide between installing an extra spring or adding air shocks. The rear springs are almost new so it is not a weak spring situation and the car rides and handles beautifully. I know I have read here that the upper shock mounts are not robust enough to handle too much weight so I am reluctant to go that route but my concern with the extra spring option is that I believe these cars look best and are meant to have a bit of that "low-rider" stance or at least not jacked up in the rear.

So my questions are has anyone actually used air shocks and caused damage to the upper mount? I must stress that the vast majority of the time I wouldn't be using the air shocks to raise the car, only on the rare occasion that I have rear seat passengers. How much higher would the rear of the car raise with one long extra spring installed and would this likely be enough to strengthen the rear so as not to sag with back seat passengers, enough to eliminate the tire rubbing? Here's a shot of the car showing it's current stance.

52318

Bills R2
03-14-2016, 09:15 PM
If the springs are original, do not rule out replacing them. You will gain 3 things:
A much smoother ride, new bushings & restored load carrying capacity.
Money well spent.

studegary
03-14-2016, 09:27 PM
Where is the rub occurring? If it is on the backside of the tires, you could just use spacers and longer lugs. This would allow you to keep the same wheels. If it is on the outer side of the tire, you can "roll" the wheel opening in the fender. If they are rubbing in the tread area, you could "adjust" the inner fender area.

Shocks are meant to control movement, not to raise the vehicle. I installed air shocks on a 1963 Daytona Wagonaire. It did not change the ride height, but did give better handling. I had them on for several years with no mount problems.

Your Hawk looks like it sits properly now.

Kato
03-14-2016, 10:32 PM
Where is the rub occurring? If it is on the backside of the tires, you could just use spacers and longer lugs. This would allow you to keep the same wheels. If it is on the outer side of the tire, you can "roll" the wheel opening in the fender. If they are rubbing in the tread area, you could "adjust" the inner fender area.

Shocks are meant to control movement, not to raise the vehicle. I installed air shocks on a 1963 Daytona Wagonaire. It did not change the ride height, but did give better handling. I had them on for several years with no mount problems.

Your Hawk looks like it sits properly now.

The rub is occurring on the outside of the tire and seems worse on the left side than the right. It doesn't rub by much as there is very little evidence on the car or the tire. How do you roll the wheel opening? Yes I like the stance the car has and I would like to keep it that way.

Kato
03-14-2016, 10:35 PM
If the springs are original, do not rule out replacing them. You will gain 3 things:
A much smoother ride, new bushings & restored load carrying capacity.
Money well spent.

The springs and bushings have all been replaced within the past 5 years and it rides very well. The real problem is the rims so I think that the load carrying is probably what it should be. It rubs on the outside of the tire and not the top.

GrumpyOne
03-14-2016, 11:14 PM
I know this has been discussed here before but the car is coming out of storage soon and I must decide which way to go. My 62GT has a tire rubbing issue when the car is loaded. The real issue is likely that the rims are not the ideal offset but I like them and want to keep them. I have 205/75s on the rear so there's not much to be done with tire size. When I drive the car alone or even with my wife there is rarely an issue unless on a very rough road. The problem arises when I put anyone in the back seat or if I were to load the trunk with luggage I would think, I then get quite a bit of rubbing while accelerating, going up a hill or with any uneven road at all.

I am trying to decide between installing an extra spring or adding air shocks. The rear springs are almost new so it is not a weak spring situation and the car rides and handles beautifully. I know I have read here that the upper shock mounts are not robust enough to handle too much weight so I am reluctant to go that route but my concern with the extra spring option is that I believe these cars look best and are meant to have a bit of that "low-rider" stance or at least not jacked up in the rear.

So my questions are has anyone actually used air shocks and caused damage to the upper mount? I must stress that the vast majority of the time I wouldn't be using the air shocks to raise the car, only on the rare occasion that I have rear seat passengers. How much higher would the rear of the car raise with one long extra spring installed and would this likely be enough to strengthen the rear so as not to sag with back seat passengers, enough to eliminate the tire rubbing? Here's a shot of the car showing it's current stance.

52318

By "new" do you mean new manufactured or re-arching?

If new manufactured, you can add a leaf and if re-arched, you could do the same but the most likely culprit is the main spring and there' s no real way to fix that except for replacement.

Another consideration, on the older Stude rear axles, the tires are not exactly centered. The driver's side is closer to the fender opening which I believe is to offset the driver's weight. I know on my '55 Prez with 215x75x15 tires, left side is too close for me to use the fender skirts.

Regarding air shocks, they can be an aid but sooner or later they will fail... Probably sooner. So I've opted to install new manufacture springs with an extra leaf as I tend to carry extra parts/tools in the trunk anyway.

Your solutions may vary...

GrumpyOne
03-14-2016, 11:17 PM
If the springs are original, do not rule out replacing them. You will gain 3 things:
A much smoother ride, new bushings & restored load carrying capacity.
Money well spent.

Yep, I agree 100%. A lot of the old "NOS" Stude stuff from Standard Surplus etc were re-arched and I got stuck with a set of these on my '55 Prez as they turned out to be worse than the originals...

Kato
03-15-2016, 08:08 AM
By "new" do you mean new manufactured or re-arching?

If new manufactured, you can add a leaf and if re-arched, you could do the same but the most likely culprit is the main spring and there' s no real way to fix that except for replacement.

Another consideration, on the older Stude rear axles, the tires are not exactly centered. The driver's side is closer to the fender opening which I believe is to offset the driver's weight. I know on my '55 Prez with 215x75x15 tires, left side is too close for me to use the fender skirts.

Regarding air shocks, they can be an aid but sooner or later they will fail... Probably sooner. So I've opted to install new manufacture springs with an extra leaf as I tend to carry extra parts/tools in the trunk anyway.

Your solutions may vary...

I bought the car last summer and the previous owner told me they were new springs. They have fresh paint on them so I assume they are new and not re arched but I suppose they could have been re-arched and then painted. The car rides well and doesn't feel "soft" at all. Yes the driver's side does most if not all of the rubbing so what you say makes sense. My concern with an additional spring is raising the back end too much but that may be the only option if I stick with these rims.

Kato
03-15-2016, 08:10 AM
Yep, I agree 100%. A lot of the old "NOS" Stude stuff from Standard Surplus etc were re-arched and I got stuck with a set of these on my '55 Prez as they turned out to be worse than the originals...

Because I didn't have the work done I am not exactly sure what I have so I'll have to do a little more digging.

swvalcon
03-15-2016, 08:11 AM
If you have ever seen a hawk frame with out the body on it so you could see the top shock mount good you would not even think of air shocks, Either go new or HD springs.

Gunslinger
03-15-2016, 09:08 AM
Talk to Flex-a-form about their composite leaf springs. They cost slightly more than steel springs but weigh a fraction of steel so the savings in shipping makes overall costs a wash.

Kato
03-15-2016, 09:44 AM
If you have ever seen a hawk frame with out the body on it so you could see the top shock mount good you would not even think of air shocks, Either go new or HD springs.

Yes, so I've been told..

- - - Updated - - -


Talk to Flex-a-form about their composite leaf springs. They cost slightly more than steel springs but weigh a fraction of steel so the savings in shipping makes overall costs a wash.

Thanks, I'll look into that.

PackardV8
03-15-2016, 09:51 AM
If everything else is as good as you say, why not consider moving the axle to give equal tire clearance on both sides of the outer fenders? It's not a particularly difficult task.

jack vines

t walgamuth
03-15-2016, 09:56 AM
An air shock will make the car ride rougher along with the other negatives mentioned already. Perhaps one of those air bags between the axle and frame might work....any body do that with a stude before?

BILT4ME
03-15-2016, 10:18 AM
In order to center the axle, it is also possible that the springs are sliding sideways on the spring bushings. If needed, can the springs be disassembled at the hangers and have a washer placed on the OUTSIDE of the bushing on the left side of the car and on the INSIDE of the right side of the car, thus, allowing less horizontal movement of the springs and rear axle during operation?

Obviously, the tire choice has pushed the limit of the fenderwell opening. The other possibility is to change tires to a slightly narrower tire.

You can also loosent the U-Bolts that hold the rear axle to the springs and shift the axle all the way to the right, then tighten down the u-bolts again in order to take up ALL the toperances to the right side of the car instead of the left.

Just a little tweaking first, before spending a bunch of money.

I have a 59 Lark and have helper leaves as well as coil over shocks on the rear to handle the load and to keep the rear elevated where I want it to be. With it in its "stock" position, it felt like a low-rider to me, as well as having worn-out springs (which i know is NOT the case for you)

Your issue is not necessarily with load carrying capacity, but with rear axle movement. As the car leans left, the body tilts and it rubs. Do you have a sway bar on the rear? if so, it may need adjustment. If not, it may benefit by having one in order to control the lateral movement.

It's also possible that the left spring and right spring were interchanged. If I recall correctly, the driver's side is different than the passenger side. Someone like @StudeRich can confirm that. The driver's side is arched more or or has heavier springs to compensate for the weight of the driver. I think.

Kato
03-15-2016, 10:31 AM
If everything else is as good as you say, why not consider moving the axle to give equal tire clearance on both sides of the outer fenders? It's not a particularly difficult task.

jack vines


An air shock will make the car ride rougher along with the other negatives mentioned already. Perhaps one of those air bags between the axle and frame might work....any body do that with a stude before?


In order to center the axle, it is also possible that the springs are sliding sideways on the spring bushings. If needed, can the springs be disassembled at the hangers and have a washer placed on the OUTSIDE of the bushing on the left side of the car and on the INSIDE of the right side of the car, thus, allowing less horizontal movement of the springs and rear axle during operation?

Obviously, the tire choice has pushed the limit of the fenderwell opening. The other possibility is to change tires to a slightly narrower tire.

You can also loosent the U-Bolts that hold the rear axle to the springs and shift the axle all the way to the right, then tighten down the u-bolts again in order to take up ALL the toperances to the right side of the car instead of the left.

Just a little tweaking first, before spending a bunch of money.

I have a 59 Lark and have helper leaves as well as coil over shocks on the rear to handle the load and to keep the rear elevated where I want it to be. With it in its "stock" position, it felt like a low-rider to me, as well as having worn-out springs (which i know is NOT the case for you)

Your issue is not necessarily with load carrying capacity, but with rear axle movement. As the car leans left, the body tilts and it rubs. Do you have a sway bar on the rear? if so, it may need adjustment. If not, it may benefit by having one in order to control the lateral movement.

It's also possible that the left spring and right spring were interchanged. If I recall correctly, the driver's side is different than the passenger side. Someone like @StudeRich can confirm that. The driver's side is arched more or or has heavier springs to compensate for the weight of the driver. I think.

These are all great suggestions and I will definitely investigate them. I had thought of a narrower tire as well which might help as that limit is definitely being pushed but I think the axle position and movement might be the first place to look. No there is no sway bar so that also might be a good option. Like was said some tweaking before spending $$$ is always a good idea. Thanks for these suggestions.

Captain Billy
03-15-2016, 11:08 AM
Private message sent

Dan Timberlake
03-15-2016, 12:10 PM
Did you mention the tire size?

Some folks have had some success machining the mounting surface of especially thick alloy wheels to reduce offset.
Some folks have thinned wheels they probably should not have.

JoeHall
03-15-2016, 12:23 PM
Instead of treating the symptom, I'd treat the cause, and simply install wheels that fit the car: 6" wide, with 3.75" backspace. With the resultant clearance, the rear axle will kiss the frame's rubber jounces occasionally, as it was designed to do, but never any rubbing by tire against inner fender.

Kato
03-15-2016, 01:00 PM
Instead of treating the symptom, I'd treat the cause, and simply install wheels that fit the car: 6" wide, with 3.75" backspace. With the resultant clearance, the rear axle will kiss the frame's rubber jounces occasionally, as it was designed to do, but never any rubbing by tire against inner fender.

Yes that is probably the wisest advice!

Skybolt
03-15-2016, 01:04 PM
I had similar problems with my 59 Lark, it was mostly fine unless someone was in the back seat, although I do have 235-60 X 15's. Noting this is a base model six sedan. This was mainly a concern when cornering, the opposite side would rub. I installed shocks for a Plymouth Fury police car that came with helper springs for extra loads. Adding a sway bar on the rear also helped. I now have an extra leaf so no problem no matter what. I did try longer shackles but nothing beats the extra leaf and swaybar. Next set of tires will be 205's or maybe 215's. I also had problems with the front until I installed the Moog CC655 springs and HD swaybar. Now with the V8 going in, instead of the six, there will be a new round of tuning.

Len.

Kato
03-15-2016, 02:03 PM
I had similar problems with my 59 Lark, it was mostly fine unless someone was in the back seat, although I do have 235-60 X 15's. Noting this is a base model six sedan. This was mainly a concern when cornering, the opposite side would rub. I installed shocks for a Plymouth Fury police car that came with helper springs for extra loads. Adding a sway bar on the rear also helped. I now have an extra leaf so no problem no matter what. I did try longer shackles but nothing beats the extra leaf and swaybar. Next set of tires will be 205's or maybe 215's. I also had problems with the front until I installed the Moog CC655 springs and HD swaybar. Now with the V8 going in, instead of the six, there will be a new round of tuning.

Len.

I've had the spring assisted shocks suggested and may try that. I already have 205s on the rear and I think a sway bar is a good idea too. Did you find the back end height of the car increased a lot with that extra leaf?

Noxnabaker
03-15-2016, 04:26 PM
My left side rubber rubbed(!) the inside of the fender but not the one on the right side so I just pulled it out with my hands.
Nice-priced too! :)

Kato
03-15-2016, 05:03 PM
My left side rubber rubbed(!) the inside of the fender but not the one on the right side so I just pulled it out with my hands.
Nice-priced too! :)

Yes thank you.. I thinks someone else suggested a similar fix. That would be simple and FREE!

studegary
03-15-2016, 08:58 PM
It depends what point in the rear wheel opening is contacting the tire. Unless it is at the very top, raising the rear of the car (new/added springs, air shocks, shocks with springs) will not help. By rolling the fender, I did not mean to pull out the quarter panel. At the wheel opening, the fender "folds" in quite a bit. Reduce this section of metal or fold/roll it around to bring it away from the tire.

Kato
03-15-2016, 09:39 PM
It depends what point in the rear wheel opening is contacting the tire. Unless it is at the very top, raising the rear of the car (new/added springs, air shocks, shocks with springs) will not help. By rolling the fender, I did not mean to pull out the quarter panel. At the wheel opening, the fender "folds" in quite a bit. Reduce this section of metal or fold/roll it around to bring it away from the tire.

OK now I understand what you mean. Yes that might work. It does contact the fender at that point and not by much either I'll have a look at that in a few weeks when its out of storage. Thanks.

Mikado282
03-15-2016, 11:15 PM
When these cars were built frame and body tolerances were measured in tenths of an inch, around 1\8th of am inch. Why do you think the assembly lines were littered with buckets of shims and dead blow hammers and why they had a "Gorilla Guy" to fit things that didn't fit? People today tend to forget how these cars were actually built. Wake up

Skybolt
03-16-2016, 12:56 AM
I've had the spring assisted shocks suggested and may try that. I already have 205s on the rear and I think a sway bar is a good idea too. Did you find the back end height of the car increased a lot with that extra leaf?

Don't recall measuring it. I would have to take the springs of the shocks to get a proper measurement. The Lark probably has a different design under the fender as the wall is closers to the tire than the lip so mine rubbed on the wall, outer. Also it was mentioned earlier about one side being closers than the other. That is correct. With stock tires one would not notice it but when it's only one finger away it is tight and easy to see.

Len

Kato
03-16-2016, 08:18 AM
Don't recall measuring it. I would have to take the springs of the shocks to get a proper measurement. The Lark probably has a different design under the fender as the wall is closers to the tire than the lip so mine rubbed on the wall, outer. Also it was mentioned earlier about one side being closers than the other. That is correct. With stock tires one would not notice it but when it's only one finger away it is tight and easy to see.

Len

Yes, with the Hawk it rubs at the lip not the wall and only on the driver's side. As you say with the stock rims and tires one wouldn't notice how much closer the driver's side is. I like the wire wheels but they do cause issues. I've had a few interesting suggestions to try and solve the issue. That's why this hobby is so rewarding.. trying to solve the inevitable issues that arise with an older car!