Hot Rods Tranverse Springs Tech Info.

I am setting up this thread, so folks can add any tit bits of information that may have which could make life easier for others who follow.
Tell us about your experiences or show off your knowledge with regard to transverse springs used on hot rod projects.

I will offer the first point as I know it;
When using a dead perch setup, I am of the belief that one side of your spring needs to be approx 3/8" shorter to accommodate the perch and keep the chassis central on the axle and sitting level side to side.

and also ponder a question that somebody else my know the answer to;
When re-curving a stock spring to obtain the reverse eye setup, does the spring become shorter or longer between the eyes if the same curvature is maintained???

Please correct me if I am wrong.

 

The main leaf becomes longer eye to eye if the same arch is maintained.

 

about the dead perch idea, would the shorter side of the spring be stiffer? shorter spring would be stiffer when all other things are the same right? Now only 3/8" may not make much difference but could you just keep the frame centered by taking up that 3/8" at the spring perches? I don't know, and have never set one of them up, just a thought.

 

I figure you are probably correct with respect to dead perch spring stiffness increasing, but it must be negligible in real terms.
So with reversing spring eyes and the spring gets longer, is that not really a good choice as the spring will hang on the shackles in a manner that I suspect ain't quite right...

 

I see this thread as a relevant aid.
I used a similar method to hold up the coil springs in my 64 Falcon while doing the Shelby top arm relocation, just used a larger rod.
https://www.jalopyjournal.com/forum/threads/re-visiting-the-very-cheesy-1-79-spring-tool.646689/

 

I had this issue, from a spring that was too long, so instead of using reproduction shackles, which were 40mm centre to centre, (1&1/2” in theory but actually slightly more), I made new ones at 34mm centre to centre. (1/4” difference).
Doesn’t seem like much, but just tweaked it enough to bring it back to where it should be.

 

Great, these are the type of things that folks need to know about when trouble shooting a project problem with transverse springs.
What methods are used to help leaves slide between each other?

 

For what it’s worth;
re post 6 above,
The axle that my spring was to be used on was a ‘32 light axle. Turned out that between perch bolts it is about 1/2” or 15 mm narrower than a ‘32 heavy axle.
Added to this we had some BB Truck perch bolts that we turned down to fit the smaller diameter perch bolt holes, not realising that the truck perch bolts were slightly different as they ‘leaned’ over more, that is the eyes were closer together than if we had used car perch bolts.
All little things that I have had to learn the hard way.
Clemens.

 

Here's the recommended procedure for painting the transverse springs I sell.

PROPER PROCEDURES FOR PREP AND PAINT OF LEAF SPRINGS Disassemble spring Prior to painting prep we highly recommend removing ALL sharp edges from the factory sheered tips of all the leaves, both top and bottom sides. I also recommend the areas at the tips of the undersides to have a gentle “sweep” so that scaring or gouging will be kept to a minimum when your spring has been painted and installed. Clean springs thoroughly with wax and grease remover or Pre-Kleener Mask off shackle bushings Spray spring with one medium coat of self-etching primer (RM 834 ZIP Primer). (This is a rust inhibitive, self-etching primer with excellent adhesion properties) Extreme care must be taken NOT to paint the contact surfaces where the leaves lay on top of each other. Only a very light “fogging” layer is acceptable. The reason for this is that any build- up of paint between the leaf springs will eventually pulverize over time and the leaves and center bolt can end up loose and potential failure may occur. Allow at least 30 to 60 minutes for “flash” time after prime coat has been applied. Spray spring with 2 (Two) medium coats of black single stage urethane paint (PPG Concept 9000 is an excellent, high quality single stage paint for this type of application.) Use a light coat of EP (extreme pressure) grease or graphite on the underside of each leaf prior to re-assembly. This will allow for a smoother action between the leaves and provide for a softer ride. Clean excess grease off after assembly with a wax grease remover and CLEAN towels.

 

Obviously center bolt integrity is paramount, meaning the center bolt head should be a snug fit in the cross member hole and sit all the way in.
The center bolt should be done up tight and if using a under plate for U bolts, the under plate needs a hole large enough to clear the center bolt nut.

Maybe somebody can tells us the procedure for installing and tightening U bolts for the best results...

 

Found this some time ago, thought it was interesting;

Installation Tips
Do not re-use old U-bolts on springs. All U-bolts have yield type threads, therefore they have a recommended torque setting, that ‘stretches’ or ‘yields’ the thread to ensure they hold firm. If old (previously torqued) U-bolts are re-torqued there is a risk that the thread will be beyond there yield strength thus weakening and causing them to work loose.

 

This is the plate that I made for under my spring.
I don’t believe that a flat plate is ideal under an arched spring, although that is exactly how all the others in the world are done !
Also shown, ford original.

 

Evenly, a little bit at a time, just like you torque a head ?

 

I have read on other threads here that by adjusting U bolts you can even level up the stance of a car should it be leaning to one side slightly.

 

Having worked in a spring and welding shop for about four years when in my late teens and early twenties ( 40 or so years ago) we never worried about reusing U bolts if an impact wrench took them off and not a blue flame wrench and never worried about torque values when re tightening. On car type applications generally nearly as tight as a fresh 1/2 impact would take them and requiring some arm to move with a long 1/2 breaker bar when checking. None ever came back loose. On LARGE U bolts ( one inch and larger) on 18 wheelers and such the torque spec was as tight as Jimmy ( me!) could get them with a five foot pipe on a three foot by one inch drive breaker bar could get them.also up to a certain point when tightening one the others loosen so keep going around or back and forth, just keep checking until all are tight. As far as leveling a car with u bolt torque if this were to work it would mean one side of the spring is not seated properly in the cross member in a cross spring application and that would be BAD ( unless you put a little " wedge " between the two....this is where the term wedge came from in regards to static weight loading in oval track racing incidentally!)

 

Maybe I should rephrase my earlier comment and say, that by incorrectly tightening the U bolts the level of the car can be set so it does not sit right.
Something I think I read on a Ford Barn post...

 

I guess you can't have a transverse spring thread without having a couple of pic's of transverse springs, can you!!!

 

Loosening u bolts or running uneven tension to compensate for uneven weight or a spring that has an asymmetrical spring rate is a recipe for disaster. All 4 bolts should be equally torqued and the spring pinched hard to the crossmember.
IF IF IF that's making the car sit funny there are ways to get it. A wedge on top of the spring is one.

 

I agree, when the car is setting at ride height on the ground, the cross member should read the same as your king pins for the correct caster and no spring bind. You can make a shim by comparing the two measurements or use adjustable spring perches.

 

Tightening u bolts has to do with left/right lean, not caster.

Caster changes as the suspension moves. Do those swivel perches move as well? Do the come loose?
They are a bandaid, yep with great fabric and good adhesive but still a bandaid.

 

I've never had them com loose but anythings possible. Either way there is some twist in the spring or on the spring perch when hitting a bump or uneven pavement.

 

Also there are some shackles out there that are manufactured incorrectly.
The shoulders on some are too short. Tightening the shackles crushes the bushings shoulders. It can also pinch and bind the shackles. The length of the shoulder should/must be slightly longer than width of the installed bushings.

Here's what I mean.
Below is a perfect example of crap that is NFG
Notice that the threads can't protrude past the face of the nuts, can't even engage the nylock

 

And if the shackel pin is not welded to the shackel plate, if can be a bitch to get the other shackel plate installed.

 

I'm curious how you shorten the spring by 3/8" on one side?

 

The springs main leaf would be made specifically shorter on one side, or else the eye of an existing main leaf could opened out and small amount of the material cut off and a new eye re-rolled making that side 3/8" shorter.

 

For a dead perch mount, that perch is made longer and lower to have the mount up hole in the approximate place where the spring eye would normally be with the shackle. Many early dead perches were made by simply welding the shackles.

The spring is the same, the mount is different . Here they are side by side, ( although the adjustable version) just picture the shackles in and that dead perch spring mount hole is pretty close.


there would be no need to shorten the spring and if shortened the spring eye would taken the wrong way. If anything making the spring longer would be better but that's not done either.

 

Since we are discussing transverse spring we might as well identify what they attach to and note the various differences between years and models.


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This information that I borrowed from a parts seller could also be helpful.
Measuring For A Spring

Method A: If you are using an axle with vertical perch bolts holes, you simply measure center to center of the spring perch bosses (taken from the top side of the axle) and deduct 5”. This will be the length you need on a spring-over application.

Method B: If you already have your axle, perches and shackles, you can assemble them and situate the shackles so they are horizontal. You can then measure from the centerline of one shackle pin to the opposite one as shown to the right. This will give you the length of spring you need.

 

Here's a chart I found several years ago, possibly from FordBarn, by someone named Marco.

 

Can anybody out there post some good oil on rear transverse springs including mounting methods to diff as well as chassis.