frame when using m105 springs

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 said:

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.

Click to expand...

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

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?

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.

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.