What leaf spring sliders are, and how you can build them in your Home Fabrication Shop.
What is better about leaf spring sliders?
Depending on setup, leaf spring sliders can provide great articulation and stability while also getting rid of big shackles that can hang down and drag on obstacles.
What kinds of leaf spring sliders are available?
Most leaf spring sliders are similar in design. All have a slot in which the bolt from the leaf spring can slide back and forth. some use small metal bearings and others use a hard type of plastic (UHMW, more on that later) to provide the sliding design.
There is no one right setup. It all depends on what you will be using the vehicle for. Now having had both the common shackle setup and the leaf spring sliders, I can readily say that both work well if set up correctly. The leaf spring sliders are a very tough design and I feel like they are more tight and predictable when used in the front suspension due to there being one less bushing and pivot point.
My favorite place to start researching is Google. You can and should start by searching “Leaf Spring Slider” but read on to learn how to make them yourself.
Everything starts with an idea, so after researching on Google quite a bit I came up with the highly accurate pencil drawing you see above (rulers are for chumps). One of these days I will learn CAD, but until then this is what we have to work with. You can see that I have the basic design laid out with some critical measurements. The thought is with the tube sleeve, I will be able to crank down on the leaf spring bolt without affecting the preload on the UHMW bushings or limiting suspension travel.
Next step is to start gathering supplies! I picked up a sheet of UHMW at ~$60 for the whole sheet from a local plastic supplier, it was an odd ball already cut sheet so he gave me a pretty good deal. Don’t be afraid to ask for “drops” or already cut pieces when you only need a small piece. I have gotten many significant discounts by doing this. I also picked up the 1/2×1/2 square solid stock and tubing. The only tubing that they had in the size I needed was chromoly. I think they overcharged me for it, but it was such a small amount that I spent <$20 for 8 ft of 1/2×1/2 and 2ft of the chromo.
Total so far, is up to ~$80 and should have leftover materials.
Here is a snippet that I have written up on UHMW, why it is awesome, and why it should be used for this project.
I have had this idea in my mind and have been doing passive research on it for a long time. I just realized that it was all in my head, and I hadn’t posted any of it to share.
There is a lot of discussion on the topic, but relatively few people that have actually done the sliders and even fewer who have posted results.
UHMW is a plastic, but as far as plastics go, it is probably one of the most high tech plastics available.Quote:
Originally Posted by WIKIPEDIA – UHMWUltra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. …It has extremely long chains, with a molecular weight usually between 2 and 6 million. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made. UHMWPE is odorless, tasteless, and nontoxic. It is highly resistant to corrosive chemicals except oxidizing acids; has extremely low moisture absorption and a very low coefficient of friction; is self-lubricating; and is highly resistant to abrasion, in some forms being 15 times more resistant to abrasion than carbon steel. Its coefficient of friction is significantly lower than that of nylon and acetal, and is comparable to that of polytetrafluoroethylene (PTFE, Teflon), but UHMWPE has better abrasion resistance than PTFE.
Most of it is way over my head, but the full Wiki article can be found HERE.
Essentially UHMW is made for bearing/sliding applications. They use if for everything from launching boats to fake knees and hips.
Self lubricating – greasing it would actually reduce the life because it would attract dust/grit which would wear it faster.
High impact resistance
Can be machined
Is not brittle, does not crack like plexiglass (excluding lexan)
It has a temperature range from -240*F to +266*F
It is still a wearable item. Hopefully it doesn’t wear out fast, but if it does, there is no risk of catastrophic failure due to the slot design.
Below are some links to threads that I have found useful about the shackle slider boxes:
Clearly the easiest way for me to do this would be to go buy the ones from Tim at Liquid Iron Industries.
But, if I buy the part, I get one part. If I buy the tools to make the part, I can make as many as I want, and I get a free lesson in the study of plastics.
If I were to do this again. Unfortunately I would probably just buy prefabricated leaf spring sliders. You can find them in a quick search for anywhere between $30-$100 dollars. I built my leaf spring sliders with long slots for lots of travel, but as it turns out the springs really don’t need that much room to travel. I built mine 9″ long with a 7″ slot but I easily could have made them with only a 5″ slot.
I hope this article helps. I know that when I was initially researching this subject there really wasn’t a lot of information. It took me a lot of time to get enough information together to build these. Please leave your questions/comments.