rear end jumping

[cpo223]

I took my truck into my dealer for (1) rear end jumping in wet mucky grass while backing my 5th wheel into my yard,& again jumping when going through loose sugar sand,almost getting stuck (2) cracked altenator bracket (3) air conditionining freezing up,& stops blowing untill it thaws, & repeats cycle.



I would appreciate some opinions as to what was told me. The jumping axle(rear end) is normal ,as this is a heavy duty rear end that locks into a solid unit when going through wet grass ,or sand and the wheels are fighting for traction causing the rear end to jump. alternator bracket replaced after a slight discussion of, was the crack just a weld spot,they agreed that it was stamped metal with no welds and replaced it. Air conditioning is again freezing up,& or, not blowing cold,& then blowing cold & freezing up. Has any one had similar a/c problems? Supposedly the replaced the evaporator word, and try again.



Thanks,Pat

 

[NDanecker]

I test drove a 04. 5 2500 with 6-speed and found the rear to hop the same way my Toyota Tacoma did when it didn't get good traction (truck parked in field with 2-3 inches of snow). I don't believe this is specifically inherent to heavy duty trucks, but to pick-up trucks in general running leaf springs.



Either way, I don't like it and wish there was a simple cure... .

 

[R.M.THOMPSON]

Spring wrap can kill parts fast !

 

[Firewalker]

Jumping rear end is the caust of the type of locker we have. Our limited slip realy showes it's true colors of fuction, while on sand... one wheel lips and then the other gets the power then that wheel slips and right weheel gets the power and back and forth and forth and back, keeps repeating this process and hat is one reason to wheel hop in sand. .



a simple fix is throw it in 4X4

 

[Firewalker]

Jumping rear end is the caust of the type of locker we have. Our limited slip realy showes it's true colors of fuction, while on sand... one wheel lips and then the other gets the power then that wheel slips and right weheel gets the power and back and forth and forth and back, keeps repeating this process and hat is one reason to wheel hop in sand. .



a simple fix is throw it in 4X4

 

[Firewalker]

Jumping rear end is the caust of the type of locker we have. Our limited slip realy showes it's true colors of fuction, while on sand... one wheel lips and then the other gets the power then that wheel slips and right weheel gets the power and back and forth and forth and back, keeps repeating this process and hat is one reason to wheel hop in sand. .



a simple fix is throw it in 4X4

 

[Mopar_Mudder]

Well not quiet.



The rear end "hoop" has nothing to do with the LSD rear, it can make is worse though do to more traction.



The "hoop" you are feeling is really called axle wrap and is caused by the long soft springs used in these trucks to get a nice ride when empty.



When you have enough traction the rear axle is trying to twist the springs. When it twists so much the springs fight back and snap the rear axle back into position, then the rear axle twists up again over and over. This cause the rear end to jump up and down and is very hard on parts.



Their is no fix for it that the dealer can do, the only way to cure it is with a traction bar of some sort, but these can really effect your ride and suspension travel. Their is a product called a "kicker shock" that is made to dapen this spring wrap effect and will not effect your ride, it may be worth a try. The more pin weight you can put on the rear the less the problem will be. Also if you can put it in 4x4 it is a big help.

 

[curatchko]

The main reason for the rear end jumping is spring wrap.



Much of it is to do with the spacer between the springs and the axle tube. This creates a lever type condition that just exaggerates the wrap... The wrap is the spring flexing and springing back between the front mount, and the axle.



The only thing the LSD does is make it worse because now 2 wheels are at it instead of one... .



The only way to fix it is with a ladder bar, or some type of traction bar device... .

 

[cpo223]

axle jump

Thanks for the info. My truck is a 2wd,so I can't go to 4wd. What you have told me is basically what the mechanic said,nature of the beast!Have to take it back in for the air conditioner,which is freezing up again. Other then that,it's a fantastic truck,& fun to drive too!

 

[DocDetonancour]

I have found that the LWB trucks are more prone to axel hop that the SWB, My SWB has not shown any "hop" as yet and it spins very easy in a little snow. Doc