spring loading or axle wrap

[tractoriden1]

does anyone else experience a spring binding and unbinding during launch? i feel it in the seat of pants when taking off and can see the hogshead rise a little, then it feels as if the springs unloading and set for the ride. i doubt it is hurting much, but it is the most annoying thing to try and trace. i even thought it may be in the sway bushings etc. i am aware of some of the aftermarket alternatives but am really interested if someone else has similiar problems. i have not driven another truck with the same problem and have met no other CTD driver that can relate.





the truck is a 00, 3500 4by with the extended cab so it also has the two piece driveshaft.



thanks in advance for any words of wisdom passed my way.

 

[Devildog]

The guys with the Bombs like myself experiance the same problems with axle wrap, There are aftermarket solutions i'm still doing research for the best one for my truck.

 

[BK]

The 4x4's are prone to it since they have that tall riser block between the rear axle and leaf springs. It acts as a lever increasing the torque/twisting load on the springs.



It can hurt a lot. It does help in weaking the springs = the problem getting worse...

It also helps accelerate wear on the Ujoints.



If you insist on using the power, get some track bars.

Of course putting on track bars means your rear gears will feel the loading more sharply...



Past posts have pointed at fabtech as having some of the better aftermarket off the self track bars.



Search on "track bar" or fabtech to find the past, but recent threads.



Bob

 

[BK]

Just ran across the recent thread I was thinking of



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=24022



Bob

 

[SFord]

I have had the same problem with my 93 4x4 Suburban and thought it was axle wrap but it turned out to be a low t-case fluid level. The fluid level wasnt high enough to lube the driveshaft splines causing a annoying thud when you take off from a stop. Just something to look for... ... ...

 

[BLACKRAM]

I had axle wrap problems until I installed the SS Ladder Bars.



Your post did not say how BOMB'ed your engine was, but with Cummins torque, everybody will get spring wrap. My launches are faster now, with zero wrap since the SS Bars.

 

[tractoriden1]

folks, thanks for taking the time to reply. i must clearify a little - the truck is bone stock- no bombs yet, and yes i do still have the wrap. i have looked at steves bars and the fab. bars and am impressed with both. the problem is that i feel i have to find what is causing the loading and unloading sensation. i do realize it is inherent that all the beasts have some wrap, but after driving some of the same truck today at my local 5star, it is clear that they all do not have this binding (if you will) sensation. sense the truck is under warranty i am putting the burden on dealer. the mechanic is willing to help and has taking many test rides with me. tc, trans, transfer case and dana 80 all new, the on component left is the two piece driveshaft and springs. my mission here is not to possibly mask a problem by stopping axle wrap, but to find the thump and after all is peachy then spend the money and enjoy the true benefits of the ss or fabritechs.





the mechanic said now that he may try that middle slip yolk since there are no grease fittings and maybe there may some bind there when hoghead raises on launch. i will let them try, since they are willing. hope i made some sense and certainly appreciate you scratching you hat hangers along with me.

 

[BK]

Since you say you see the Axle actually wrapping I dont see how it could be any thing up stream from axle. A binding from the input of the axle up to the transfer case would inhibit torque from being applied to the axle, which means it wouldnt warp.

I could see the if the UJ was binding at the axle... put thats as far "up" the drive line I could see.

You say the axle is new... all new, even the ring/pinion/spiders/axle shafts??

Maybe the carrier or a spider is binding?



If the axle has a clean bill of health and so does the UJ. . and you still see the axle turning. . check the Ubolts holding the axle on. . the plate that supposed to be welded to the axle, that locates the axle to the springs... Cracks springs? Bad bushings in the hangers for the leaf spring pack?



If the rear suspension has a clean bill of health, Frame?

Cross memebers?



Front brakes hanging up? Rear brakes hanging up? Have you taken the rear drums off. rear brakes miss adjusted?



For the axle to wrap it either is moving because whats supposed to be holding into place is busted, or theres a lot of torque causing to to wrap as it trys to over come what ever is holding it back?



When it comes to thinking, to hold out for most dealer mechanics todo that. They get paid "more" if they get a job done faster... no one wants the hard ones, and they'll skip over it to get the hours for an easier job...

Sorry but I really think your gonna have to tell them what to fix.

 

[Bad340fish]

When the axle wraps it extends that slip yoke at the front of the second driveshaft. If it possibly were dry or had some kind of bur that may be his bery problem. Sounds like your dealer is really trying to help you out here. Have you replaced the rear shocks yet?? One could have a bent shaft or a binding piston and cause the same symptoms(I would think) keep us posted

Clark

 

[tractoriden1]

just a reply to let all know that the problem was loose u-bolts. can you believe that. this was even after the 5star replaced my dana 80 the springs were not torgued down enough. looks like they just took the nuts down with an air wrench and did not wrench them down the rest of the way. it took a lot of looking under other trucks and just plain comparing. hope this will help someone else as well. thanks to all who shared their opinions.

 

[BK]

Thanks for letting us know...

Glad to hear you got it fixed.