Bobbed deuce 105 trailer spring u bolt size

I've been using the search function for a couple days trying to find this information but I'm having no luck.

I'm going to be bobbing a deuce using a 105 trailer frame section and springs bolted to the bottom of the deuce frame with gussets welded in to the trailer frame section for added strength. What I can't seem to find anywhere is what size u bolts people have used to mount the axle? I'm trying to gather up all the parts I need before I start because where I live it's not a quick trip to the store for parts. Any help would be appreciated!

Bueller?....Bueller?

This is just my perspective, but I've seen many Bobbers done by welding the M105 frame section to the truck frame and using the trailer springs, and I've seen ones done using M35A2 front springs instead. Gotta say I really don't like the looks of the ones done with the M105 frame section, or done by bolting the trailer springs directly to the truck frame and using 4" lift blocks. I wound up buying an M35A2 that had already been Bobbed by Boyce Equipment, using the M35A2 front springs. So glad I did. I really believe it gives the truck a much cleaner look. If I were doing the bob on my own, I'd hold out until I could get the front springs/mounts/bolts/plates set up.

Have a great weekend

MN

I need this information as well for my deuce 4x4 project but (the subject of this post) has not been answered (in this thread).

I'm using M105 springs and frame mounts and both of the steel plates at the axle connection.

The springs are 2.5" wide. The 4 bolt plate from the 105 is part of the perch/saddle and so is the other spacer plate (about 7/8" thick) with the hole to clear the spring pack bolt nut. The plate with the hole is having a 1 1/4" dia x 1/8" relief milled in to clear the washer that is part of the spring pack. I'm using an additional plate that tapers about 2.8 degree as part of the perch to make the face of the driveshaft closer to parallel than using the spring alone and flat plates. Pic is the angled part and when back from machining, I'll post up the 3 part perch weldment.

The M105 U-bolts appear to be 3/4"-16. I was planning a plate on top of the spring and using straight bolts but I'm going to price custom made U-bolts.

What have others done for the bolts? I'll post dimensions when I have all the info.

If you have 2 spare 105 spring plates and want to get rid of them, pm me. I'm using mine for the perch's.

thanks

Making changes that affect the U-bolt length so posting it here.

I'm reducing the spring pack, increasing the perch height and adding a flat under the U bolts to mount an air bag directly over the spring.

Tomorrow I take the springs apart and remove 5 leafs and modify (shorten) the lengths of some, keeping in mind that axle wrap can happen more with thinner spring pack and a higher perch. A few leafs may be cut shorter in the back than the front, because torsion (wrap) is acting mostly on the front of the spring. Air bags are standard 2500# x 2.

I want to maintain about 3" higher frame in the rear than the front (at the axle CL). I will use the thicker end of the wedge (cutting a new piece) above to reduce my pinion angle. Perch will then be about 4" from the top of the axle to the bottom of the spring. I'll post up what it actually comes out to be.

I'll have U bolts made from 3/4" to saddle the spring and the plate above it and thus need a second plate like above for under the axle, where the nuts are. I'll post up my perch assembly and spring and calculate the U bolt length on the next post.

Maybe nobody will do this but if you are using M105 springs, unloaded, you will have nearly no spring travel at all and a very rough ride. My back needs a softer ride and maybe someone else will want that too.

This is the mount that goes on top of the spring to attach the air bags. There is a 3/4" offset to keep the bags from rubbing the frame. The 1/2" cr flat will be held on by the shackles. Shackles are 3/4" .

The spring pack pack is a lot of work to clean, round off sharp ends, and primer. Never- seize will be used generously between the leafs then all gets paint flat camouflage black (enamel).