Tie rod thread engagement...

[aarvig]

Hey guys,
I am wondering what the minimum depth of threads are required for a tie rod to be safe. I measured the depth of my tie rods to be just shy of 2 inches. (Capable of being screwed onto tie rods about 2"). The drivers side tie rod end has about 1 1/4 inches of thread inside it while the passenger side has about 1 1/16 inches of threads inside. Is this safe enough thread engagement? With these settings the rotors measure pretty close to parallel. I am just concerned that tie rods don't have enough thread engagement to develop maximum strength. Looking for advice guys. Thanks!

[mikeinatlanta]

Generally speaking, about one bolt diameter on steel and 1.5 on aluminum, so the tie rod is fine at one diameter. This Fastenal link explains in more detail. Clearest illustration of thread loading is this picture showing how much load each individual thread carries.
load-distribution-chart.jpg

[CraigS]

Your 1 1/16- 1 1/4 will be fine. IMHO the rule of thumb Mike posted works fine but I see it as a bare minimum in a tie rod application. I think about bouncing off a curb when the tie rod is put into compression and only a 1/2 inch of thread engagement makes me nervous.

[edwardb]

The other thing to watch for with tie rod ends is that they're adjustable so the threads you have engaged now might not be the same after alignment. The guidelines mentioned are fine, just make sure that's what you still have after alignment. That's one of the reason I like the Moog tie rod ends. The way they're designed you always have full engagement and it's easy to see.