G2s Hot End and Build Plate alignment

[Plastic Wrap]

I need help with the leveling of the heated print bed. And, specifically the two hot ends to each other, and to the HBP.
I have the GS2 with two extruders.
I have followed the build instructions - the build was fairly straight forward.
I am about half way through the calibration. I am at the point where you level the two Hot Ends. This is where I am stuck.
When the print head assembly is at the Z axis (p2 script), the front Hot End (extruder 1) just touches the build plate, and the rear Hot End (extruder 2) is about one mm above the build plate. However, when the print head assembly is at the X or Y axis (p3 or p4 script), the rear Hot End touches the build plate and the front Hot End is about one mm above the build plate. This is opposite of what you would expect. And, I cannot figure out why this is, or what to do to fix it.
I have checked the build plate for level (equal distance above the acrylic all around). And, I have checked the build plate for warps. Both are fine (the HBP is level and is true/flat). It is like there is some geometry going on here that does not keep the print head assembly level to the build plate, as it moves around.
I did check a couple of the diagonal rods, to see if they are the same length. I found they could differ from each other by as much as one mm (give or take).
Is the difference in diagonal rod lengths a possible cause for the uneven level of the head assembly?
If so, how do I adjust the rod lengths? The rods seem to be a fixed length, and not adjustable.
I am not sure what my next step is.
Any help would be greatly appreciated.
Thanks in advance.

[Mark]

I think you need to re adjust the length of the diagonal rods, here is a method for you:
http://www.geeetech.com/forum/viewtopic ... 095#p30095

[Plastic Wrap]

Here is an update...
I adjusted the lengths of the diagonal rods. They are threaded, and glued. Lots of heat will soften the glue. And, because both ends of the rods are right-hand threads, I was only able to get the lengths close (within a half-turn's worth the threads).
In the end, this made a huge difference in the level of the Spider, to the HBP.
Thanks Mark for the link.