frame when using m105 springs

[tobyS]

What is the distance that the frame is extended down when using m105 springs and mounts when bobbing or making 4x4. You can see a bolt at about 4" from the bottom on the 5" trailer frame.

I dont want want the mount bolt in line with the frame flange, so could go 5" or 3". I want to sit slightly rear high but I'm concerned it will be too high.

Which do I go, 3 or 5?

Im having a 1/4" plate 8' long bent to an L to lap the side of the frame and really want to get it right.

 

[gentrysgarage]

I went with 5 as all the research I did showed the guys putting 4 plus inch spacers when they mounted them to the frame. If you went 3 you always have the option of adding a spacer (1-2 inches much better than 4+) under the springs or rearching (which is what I will do when I get rid of my temporary top spring and have bed, tanks, spares mounted. Did you see my last youtube video? That was with 5 inches but the rear rear of the truck is stripped of all weight.

 

[tobyS]

I went with 5 as all the research I did showed the guys putting 4 plus inch spacers when they mounted them to the frame. If you went 3 you always have the option of adding a spacer (1-2 inches much better than 4+) under the springs or rearching (which is what I will do when I get rid of my temporary top spring and have bed, tanks, spares mounted. Did you see my last youtube video? That was with 5 inches but the rear rear of the truck is stripped of all weight.

How did the 5" dimension work out? I have not seen the video. Put a link to it here...thanks

 

[gentrysgarage]

Here is the last video:
https://youtu.be/2S6XkoXEJIU

I am happy with the 5 inches. I had also deliberated with mounting underneath the frame and using aftermarket RockCrawler hangers...but in the end, I chose stability over a little more flex. I touched on the thought process as I posted videos...link in my signature to all of them.

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[tobyS]

Thanks GG. I watched the video. I measured the distance on the M105 frame to the bottom of the spring pack and went to each axle to compare. At the rear I have an average of 2" difference as it sits and on the front, 3". So my rear must have sagged a little. That's without altering the 105 spring. My dilemma is to be flat would take 3" and 5 " is 2" higher. I'm not sure empty I want a full 2" higher on the rear. But if I removed about 3 leaves, that would only be 1.25" higher.

Did you soften the spring up any (remove some leafs) or use the spring as-is? Does it seem to ride hard? Would you take some out if you did it again?

 

[gentrysgarage]

Thanks GG. I watched the video. I measured the distance on the M105 frame to the bottom of the spring pack and went to each axle to compare. At the rear I have an average of 2" difference as it sits and on the front, 3". So my rear must have sagged a little. That's without altering the 105 spring. My dilemma is to be flat would take 3" and 5 " is 2" higher. I'm not sure empty I want a full 2" higher on the rear. But if I removed about 3 leaves, that would only be 1.25" higher.

Did you soften the spring up any (remove some leafs) or use the spring as-is? Does it seem to ride hard? Would you take some out if you did it again?

Hi Toby,
What is the saying, Your mileage will vary? Before I pulled the trigger on my build I researched the heck out of all the Bobber and singling threads I could find for well over a year. What I found is that if they did not make their own perches they added 4 to 4 1/2 inch spacers to bring it up level. I went 1 inch higher as there is a great article in the lost reaches of the web written by a guy who repaired frames and he had 2 rules of thumb that pertain to this modification: Always avoid holes in the last 1 nch of the web and holes in the top flange. Thus with the M105 perches you would be stuck with (off the top of my head approximately 2 inch spacer or the 5 inch with a flange. I want to use my truck as a truck so I don't want to decrease the payload capability with removing springs. Speaking of the springs, the springs I used came off a G506 stationed on the locomotive "Pit Line" at Mira Loma then was a concrete truck for 47 more years and believe it or not were in better shape than the G7123 that spent the same amount of time carrying grapes!

In my dreams my truck rides and corners like a 1969 Camaro Z28, but we shall see what it ends up as. As my springs are undoubtedly toast I planned on having them rearched with a new top spring (the G506 springs have a smaller spring eye) or get new springs altogether once I get the Cummins/Eaton and build a bed for it. For what its worth in all my pictures from the porch my frame is level with it sitting on the G506 springs but with the slope of my drive way who knows how leve it is. I am working as fast as I can to get this done, but MONEY followed by time is slowing my Road and Track review down! LOL!!!

With all this being said in your case if you are going to avoid going to a spring shop I would suggest you look into a hanger perch that would put the top bolts of the M105 perches 1 1/4 up on the web of your frame channel and use a axle spacer to trim to level.

Man I need to save this as it is alot to type and I am sure I will always want other bobbers and singlers to benefit from my countless hours of research so they don't have to waste their time cursing the now ugly commercialized search engines that are near worthless if the can't make a buck on the result!

 

[tobyS]

The spring pack on my 105 is huge and includes the overload. While removing a few springs would soften it slightly (and reduce height 3/4" if I'm using the 5"), I'm undecided about keeping the overload. If it really has a load, I might be glad I kept it.

Here is the question of the day, how about mounting this Geithner shelter behind the cab and then shorten a 105 bed for the very back. I would have pintle and could do a gooseneck trailer to a ball under the bed surface.

 

[tobyS]

I bought steel for my truck frame today that will lap the side of the existing frame and stick down 3" beyond. I didn't want to go 5". It is 1/4" plate with a 90* L shape, 11" x 3" x 10'0". It laps a full 8" on the OE frame, from the back of the cab back 10'.

I'm not mounting the above enclosure, there will be a spare tire and Roll Over Protection (ROP) structure, that will have a winch above the tire and a top cover extend over all of the cab as part of the ROP. And an M105 bed.

This frame reinforcement extends to the ROP/ tire and winch mount, just behind the cab. I'm sticking a 395 tire up there but don't want it to stick too far past the M105 bed sides

I found my bottom angles for the spare tire frame and the ROP frame. Look how a 5 ton spare holder uses angle maybe 2x2x 1/4". I'm using a heavy angle 3 1/2" x 5" x 1/2" thick as the main frame of the ROP/ spare tire and winch frame. The spare tire holder has to have 16" width and with the angles turned in, the 5" will be up, giving it incredible strength, right at the front of the frame reinforcement.

Finish on the metal has to be done before the frame is assembled so I don't have raw metal sandwiched together. I bought red rustoleum primer and flat black oil based rustoleum. I'm having a shot of blue put into the flat black to try to make it look like black FS 37030. I'm staying with oil base flat black on the frame and undercarriage.