...been poking around FABO, BBD and the /6 forum(s) looking to learn about leaf spring sliders.
There are a lot of interesting discussions out there, but there is one concept I haven't come across yet: factory-positioned springs using sliders.

looks like anybody running slider assemblies has also moved the springs inboard, and then mounted the slider housing on the under side of the frame rails (and moved spring perches on the axle housing, narrowed same, and in some cases tub/minitubbed) .

Are there any known instances of sliders on a late A body without moving the leafs inboard?

...putting together a gusseted bracket to provide a perch just outside the rail seems relatively straight forward- the 4x4 crowd is all over that; but 1) I don't yet trust my welding ability for something as critical as a suspension mount 2) seems like this wouldn't be an original idea- is there a solution to this question that I just haven't come across yet?
Surely I'm overlooking some things...

Slider brackets are used with other traction improvement additions (ladder bars, leaf link, etc.) so there is no binding caused by the different arks of motion.

You could build the new system using the current leaf spring location but that would drastically limit the improvement, due to the limited tire size / wheel opening found under the A Body Mopar chassis.

In general, the Mopar leaf spring rear suspension system is well designed with the major limitation being the amount of tire you can get under the car.
Based on this, the first step is usually moving the springs inboard and opening-up the wheel well... to get a bigger tire in there.

Once you have enough tire, then you re-evaluate to see if you need additional traction control devices.
DD

Thanks for your insight, DD

Guess I've never really been able to reach the limitations of the tires that fit without making extra room...

I had installed a set of the poly bushings in an attempt to add some stability to the car.
The improvement was significant compared to the 30-some year old rubber that came out!
But the noise... My word!
(Not trying to restart the big debate over bushing materials.)
Interestingly, it's only the bushings at the shackles that moan/groan& pop. The front doesn't make abnormal noises.

Guess I was just looking at sliders as a way to eliminate the noise, add some further stability, and as a (positive/negative depending on one's perspective) side effect a slight reduction in ride hight.

I've read conflicting stories about the sliders making noise-
Some say 'nah' plenty quiet. Others report loud bashing noises.
I'd suspect that big bangs would be the result of poor installation, and the slider car slamming into the ends of the housing during max travel in either direction.

So what's the verdict in this group?
Would it just be trading one noise for another?

I have sliders on my DeSoto with B/E leaf springs. It was an easy way for me to package longer springs .

The sliders are a nice way to get rear ride height right....you just block the sliders tilll you get what you want.

They make some noise when dirty......

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

Coming from the off road world where we see enough arc of shackle motion that a slider is appealing (in some ways) because with those the spring rate stays consistent thru the whole travel range.

In a compression shackle design (like my '65 Valiant's rear design) the minimum shackle length is the difference between the eye to eye straight line length of the main leaf and the eye to eye length along the unloaded curve of the main leaf. That is the minimum length that the shackle should be, not the max length.

Another factor in spring rate is the shackle's angle at rest. The more that it is laid over, the lower the spring rate will be. A slider will always have one spring rate, where a shackle has a variable rate within the range of motion and defined by the spring's actual rate and the starting angle of the shackle.

This may be easiest to visualize by picturing the at-rest shackle angle first to be straight up and down. Now mentally compress the leaf spring 2" and lets say that such a movement makes the spring 1" "longer." That moves the spring end of the shackle rearwards by 1". Since the shackle was vertical it now is angled back, but because it travels in an arc it also caused the spring eye to travel up a slight distance. So even though the spring deflected 2", the actual wheel movement may have been 2-1/8" If that is the case then the effective spring rate (commonly called the "Wheel Rate") will be less than the spring rate. If the spring has a 100lbs/in rate then it should have taken 200 lbs to compress it that 2" Since the wheel moved 2-1/8" that makes the Wheel Rate 94 lbs.

Take it to an extreme, let's say that the at rest shackle angle is 45° Now when the spring extends that 1" the starting point of the shackle means that the shackle end of the spring also moved up an inch. So a 200 lbs force on the tire compressed a suspension with a 100lbs/in spring 3" Which makes the Wheel Rate 66lbs.

Now picture this same suspension, but with a slider. When the wheel gets a 200 lbs. compressive force applied to it the 100lbs/in spring deflects 2" Making the Wheel Rate with a slider identical to the spring rate no matter where in the suspension's range of travel. Crucial is that the slider be mounted "flat." If mounted at an angle then it starts to have similar Wheel Rate issues as does the shackle.

I have taken some liberties with geometry and trigonometry in this explanation to make it simpler. Even with those things tossed back in the concepts are the same and the numbers won't differ by a large amount.

Perhaps there is another reason for using them, but it eludes me what it might be.

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Thom

Cross-threaded is tighter than Lock-tite

Let see, we don't like the poly bushing because they "squeak". But we want to replace them with a steel bearing that rides on a steel plate that probably has an aluminum bushing in the spring eye.

I don't think you are going to eliminate that "squeak".
.
15 years ago when I installed the poly bushing in my Darts leaf springs. I liberally coated them with bearing grease and they have never "squeaked.

The one set of sliders that I've seen in person (no idea where they came from or who made them) have aluminum "tires" pressed on the OD of the bearings and those are a close fit between the plates that they ride on. Probably still can clank a little, but with their minimal clearance likely not very loud.

A friend and his wife own a 4x4 repair business (she does the trans and transfer case rebuilds and I think that's awesome!). He once told me that in 20+ years of installing urethane bushings that when they squeak they need to be replaced. Does not matter if they went 10 feet or 10 years, they need to be replaced when they squeak.

He has had good results with the silicone grease that Energy Suspension sells and Baker Precision sells in larger tubs for a lot more staying in the bushing longer and working better than any other grease that he's tried.

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Thom

Cross-threaded is tighter than Lock-tite

When I say the sliders make some noise when they are dirty I did not mean to imply it was anything to worry about . The sound is definitely less annoying than squeaky bushings.

,,,,and you can always wash them.

The best part of the sliders so far has been the easy ride height adjustment.

I like the way the car handles with sliders ......but its not measurably better than a good shackle setup.

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Yeah....Im the one who destroyed this rare, vintage automobile.....