My 34 truck sits very low and I like that. Trouble is I have about an inch of front suspension travel before the axle hits the spring plate. I would like double that. I was thinking of going with a reverse eye mono leaf and eliminating all but one top spacer and using a good quality bolt to hold the center to the frame crossmember. (My spring is a little flat) I will be adding a panhard and my frame is notched for spring clearance. Basically I need to eliminate the spring ubolt plate completely. Thoughts?
I’ve never held a spring without the clamp. I’ve swapped the spacer to the other side of the spring before to lower it I don’t like the idea of placing the spring into a single shear with all the leverage from the spring.
I have a monoleaf too but I wouldn't mount it by the center hole - they have a reputation. You can eliminate the stock style u bolts and plate with a thinner plate that bolts to ears welded to the crossmember ( see p& j??). Notching the crossmember can allow clearance to the now raised plate. A 32 rear bump stop can sit nicely between the plate and the axle. I won't tell you how much travel I haven't got above my axle! Been meaning to fix it but I can't stop driving it. 60k in already. Might get to it one day! The simple bump stop made a night and day difference I must say. Chris
There are forces being held in check by the original design , if the factory could have gotten away with one bolt , they would have !
I have done that to my coupe, I plan to fab a seat for the top radius of the spring to prevent roll or maybe a thin wedge screwed on either side of the mount bolt. Grade 8 bolt just in case. I also have a pan hard bar which locates the front axle instead of the spring, so even if the bolt shears I can make it home.
The steel mono leaf springs had a spring rate of 500 lbs/in per side for a total of 1000 lbs/in. It takes 1000lbs to move the front end one inch. The stock springs were about 140 lbs/ in per side. Most aftermarket springs are about 250 a side. I rode in a roadster with a steel monoleaf. My arm that I had on the door started hurting. Going over tar strips was so violent it was beating my arm up. I put my arm in my lap.
I screwed up, I don’t have a mono-spring, but I plan to vary the spring stack to get the ride height I want, then get the correct bolt length to retain the spring pack! Maybe even re drill the holes and up the size of the bolt! I like the spare bolt idea too!!! I plan on carrying spares, points, condenser, etc!!
The spring must be rigidly clamped in the center 3 or 4 inches. If it is allowed to flex in the middle it will eventually crack through the bolt hole. This is a common failure (especially on mono leafs) and is usually the result if improper installation.
There is no way I would run a spring held only by the centre bolt! Also no way I would make the bolt hole any bigger. May as well cut the spring in two.
All of this talk of retaining the front spring by the center bolt has, in my opinion, just created a new version of a suicide front end.
Let us know when you are going on the road with it, so we can all stay home....This is a horrible Idea
This sounds like a bad solution to a problem that actually doesn’t even exist. Extra points is needed mostly due to the poor quality of modern points purchased today. Carrying an extra suspension bolt/s is evidence of poor design.
No way I’d do it. Also, forget the spare bolt idea - you’d never get one in with the radiator in place.
You asked for advice. Sorry you didn’t get what you think you wanted. Honest advice isn’t being an asshole
I've done a number of customer chassis with a monoleaf and have used the P&J weld on spring clamp. Even though they were clamped tight there have been several failures thru the center hole. Only mono leaf I use today is the Posie Dual Flex.
I asked for a discussion of mechanical concepts. Not "are you building a rat rod" " Let us know when you are out so we can stay home"
And? That happens. My junk get the “RAt rOd” label often. It is what it is. There are more constructive and informative comments than those. Forums are open to discussion. There are responses here from experienced builders and engineers. That’s worth filtering the comments that may be less constructive.
I understand what you guys are getting at! The pan hard bar is the game changer, no side(shear) loads to deal with. With the weight of the car on that area it can’t possibly come out and it can’t move around thanks to the hairpins and pan hard bar locating the front end, and that eliminates the side loads on the spring mount in a turn. I think I will make some larger mount area doubler to prevent frame failure. Or start over !!! A coil over puts up with the same loads, but it relies on the radius rods and pan hard bar to keep the rear inline! Kinda the same thing? And she might be considered a rat rod , so be it!!
"Are you building a rat rod" was a valid question, leaf springs have been used for what a hundred and twenty years in the automobile. If the clamping force provided by the U bolt was not needed it would have disappeared from use long ago.
True but only when no pan hard bar was used and the mount had to deal with side loads from turning? I think it also prevented body roll when cornering. It’s sort of rat rod hot rod mix! Hot rat rod? So I plan to use several springs of different lengths till I find the right mix to achieve the ride height I want! That will give more support than a mono spring at different points.
If the scrubline is infringed upon it is squarely in the "ratrod" category. Otherwise, I will be interested in any solutions that would be considered safe and workable.
Maybe I have too much shiny stuff down low to be a rat rod! I am not familiar with the rat rod requirements.