Spring seat design

[New_Era]

Purchased 1963 SuperSkeeter with original trailer, manufacturer uncertain. Leaf springs are shot and ordered new ones. Trailer, before installing new springs, sitting pretty high with the spring on top of the axle. Noticed that the spring seat is welded to the bottom of the axle. Would the spring seat on the bottom of the axle indicate that the original design/intent was for the spring to be attached underneath or above the axle? If I mount spring undeneath axle is there anything I need to be aware of/concerned about?

Thanks,

Ron

 

[tashasdaddy]

Re: Spring seat design

it depends on the trailer, some are mount on top of the spring, some under.

 

[Silvertip]

Re: Spring seat design

If the spring seat is welded to the bottom of the axle, that's where the spring is supposed to be. The center bolt or rivet in a spring is supposed to be captured in the hole in the spring seat. Without that feature, the axle would be free to shift on the spring regardless how well it's clamped. There is nothing else you need to be concerned about. The rear shackle or slipper setup works the same either way. You might want to check the axle to see if it is a cambered style or not. Cambered meaning having a slight upward bend in the middle. Stand back about twenty feet from the back of the trailer and look very carefully at the center of the axle. If it appears bowed up, it is cambered. If it bows down the axle has been installed upside down or its bent. In your case since the spring seat is welded to the bottom of the axle, it is apparently installed upright, just below the spring rather than on top of it. It may have been that the prior owner needed a little more fender clearance for bigger tires so he mounted the axle under the spring. Another thought is that the prior owner replaced the axle with whatever he could find and didn't give the instation enough thought.

 

[NYBo]

Re: Spring seat design

Unless it's a drop axle, there is really no top or bottom, is there? You can just turn it to mount it either above or below the springs, correct? Kind of like the "710" cap on your car engine!

 

[Silvertip]

Re: Spring seat design

Drop axle or not -- the spring seat is always welded to the axle and the axle must be ordered for over slung or under slung application. The only way you have a choice is if you order an axle without spring seats. You then weld those on yourself or have a shop do it. Only then can you decide which way you want it.

 

[reelfishin]

Re: Spring seat design

There will only be a top or bottom of an axle if it's either a drop axle of if there's a set amount of camber built into the axle, in other words the axle is bent or curved to allow proper camber under load.
Many older trailers with straight axles or solid bar stock axle beams are built straight with no camber and I've found many that have sagged over the years as well. A good front end bending jig can also re-camber a solid axle. I've done it hundreds of times on small trailers and RVs, as well as on home built axles.
If you do flip the axle over ontop of the springs, be aware that it may limit axle travel since the axle is now closer to the frame. You will also have to most likely reverse the spring center pin or bolt to orient it towards the axle plate.
The round end or bolt head normally goes towards the axle unless the axle or plate has a large enough locating hole to clear the nutted end of the center bolt.