Spitfire Mk3 rear spring

[Plumcrazy]

Greetings,
i have a non internet savvy buddy who is having a problem with his 1969 Spitfire. The rear wheels when driving down the road have an incredible amount of positive camber. He continuously is replacing u joints. Self doubt crept in and he asked me to put together another half shaft assembly for him. He went 25 miles before the clicking returned. He has tried two new springs (one from The Roadster Factory and one from Victoria British). Both springs have the same result, massive positive camber. My theory is the spring is causing the u joints the fail because of either odd operating angles or the suspension is binding. When you push down on the rear of the car it seems to articulate through its travel without binding but maybe something is happening when the car actually gents driven.
I don't have a ton of experience with Spitfires but I do have a fair amount of experience with "new" springs and I'd say about 75% of the new springs I have installed are too stiff or too long so I am very skeptical about his replacement springs. I'd like to try and get to the bottom of this for him. Any suggestions or things to check would be appreciated. if you need more info please ask and I'll do my best to answer.
Regards
Craig

 

[dklawson]

There are "rubber" buttons between the leaves of the spring. They disintegrate over time resulting in too much curvature. The springs can be disassembled to replace the buttons. Instead of the rubber ones you can buy Nylon buttons on eBay. Search using the phrase "Triumph leaf spring buttons". The thicker the button, the flatter the assembled curve will be.

I made buttons for my car since I had access to a lathe. I made two change to the design you will see on eBay. I made the small diameter of the button "shorter" so it would sit in the spotfaces on my car's springs. I also drilled a 1/4" through hole in the center of each button and chamfered each side of that hole. Those changes allowed me to have the buttons rest flat on the leaves and it allowed me to squirt RTV into the center hole to hold the button in place during assembly.

I also suggest you take a look at Paul Geithner's website. He has some information on making your own buttons and what replacing them. (link below)
https://auskellian.com/paul/links_files/performance_enhancements.htm

This made a world of difference in my car.

 

[Andrew Mace]

Doug, unfortunately, your response does not answer the original question. Those "buttons," most often discussed these days in relation to the swing spring, help to eliminate the "spring sag" on the swing spring-equipped cars. In other words, they decrease the negative camber. Unless I'm missing something here, Craig is referring to the older style of "fixed" spring. That said, I have heard that excessive positive camber with new springs can be an issue.

Craig: two points. One, when each new spring is installed in the car in question, and/or whenever u-joints or other parts of the rear suspension are replaced on this car, is final tightening of all bolts (spring eye, shock, radius arm, etc., etc.) done in a "load" condition? That's easily done by having the car on stands, then carefully jacking on the bottom of the vertical link until the car just begins to rise off the stand(s). THEN all bolts can be tightened to spec. and the car lowered to the ground. This way, the various bushings aren't pre-loaded in "full droop" condition, which can tend to keep the rear suspension in a significant positive camber stance.

Two: if all else fails, there are lowering blocks available in .5", .75" and even 1" thicknesses. They go between the differential and spring and will reduce the positive camber, hopefully introducing the more desired slight negative camber. The spring could also be de-arched by a good spring shop (hopefully those still exist somewhere), which would have a similar effect.

 

[dklawson]

I'm sorry if I misunderstood the issue.

 

[Plumcrazy]

Thank you both for your replies. Doug, the website you linked looks like an absolute gold mine of information. I only got a chance to quickly scan the rear suspension section but the pictograms showing the the rear suspension in action are fabulous. With the positive camber this particular car exibits I can just imagine the u joints are really being stressed.
Andy I have to admit, I did not have the suspension loaded when things got torqued down. I'm going to try that first. I don't think it's going to get all of the camber out (probably +4 deg ??) but your absolutely correct that's the way it should have been done.
Regards
Craig