Rear end travel direction under compression

[RLDSL]

Does anyone happen to know if the rear axle travels forward or aft when the springs are under compression?
I just installed one of those nifty Mag Hitech diff covers and it only leaves about an inch of clearance at the top on the backside where a piece of channel comes down from a custom spare holder. It would be a fairly simple thng to cut it and re brace it, but it would be even easier to just leave it alone
Thanks-------Robert

 

[icanfixall]

Connect the truck to the 5th wheel and watch the springs travel either direction. I'm guessing it moves forwards but have no reason to give that a fact.. Just a WAG...

 

[chevytaHOE5674]

Moves rearward under compression...

 

[91idi]

Shouldn't move at all. If it does get more springs!

 

[MUDKICKR]

the axle is always going to move towards the shackle, be it in the front or rear. the other side is a fixed point for the spring, which keeps everything in line when cycled (pivot point). so if the rear springs have the shackle on the rear part of the spring, then when cycled the axle will move rearward

 

[Exekiel69]

I'm going to have to disagree with the other 3 comments .

 

[MUDKICKR]

I'm going to have to disagree with the other 3 comments .

this is the internet, where everyone is correct.

 

[RLDSL]

this is the internet, where everyone is correct.

Aw cmon, can't we have a long drawn out fight over it..... PlEEEEAASE

 

[antiqueford]

Aw cmon, can't we have a long drawn out fight over it..... PlEEEEAASE

It will self-clearance!

 

[OLDBULL8]

Aw come on Robert, just drive the the big truckin, when the cover breaks and oil is on the front of the 5er, then you know the springs move rearward too far. Only after five gallons of oil is spilled is it a EPA issue.

 

[icanfixall]

Well I learned a couple of things from this post so far...
1] I was wrong
2] The differantial would seem to move towards the shackle
3] EPA wont bother us for an oil spill less than 5 gallons....

 

[KyleQ]

The shackle shouldn't be straight up and down - it should be canted back for forwards (I'm almost certain it is back) meaning that your springs will move backwards with weight applied.

 

[OLDBULL8]

Oh, come on, just look at the spline on the drive shaft at the tranny or support bearing, it's all the way in, then goes out when accellerating = axle wrap.

 

[subway]

the front of the spring is hard mounted - fact
the leaves are arched downward - fact
if the front of the spring is hard mounted and you flatten the arc the rest of the spring will move away from that point, at least until you start getting into a negative arch.

i would want a little extra for frame flex and bushing movement if it were me.