HFS Spring Packs too stiff?

[UNO_RACING]

Well I was chatting with a buddy of mine about the recent problems I've had with breaking the pinion pin and rear driveshaft. My buddy seems to believe that the spring pack from the HFS lift is the cause. He said the spring pack is way too thick and it's designed to pull a 12,000 pound trailer on a 1 ton truck.

Apparently the springs have no give when going up, across or thru challenging obstacles which then causes the axel to hop and things to break. He also said that building a traction bar won’t help because it will only make things stiffer.

Interesting comment he made is that when I accelerate my truck at highway speeds there is no give in the springs, i.e. the rear does not drop. Based upon all the stuff that has been broken on the truck, I’m beginning to think that he’s right.

What do you guys think???

[Spud]

I'm running the 4" HFS.

IMO it is way stiff. I think it is basically engineered/designed with the idea that you are running a 40 with modified bumpers, full cage etc., and all manner of extra weight. If that were the case, perhaps it would be not as stiff.

I removed one leaf in the fronts and it did make it a bit more plush. I am thinking about pulling a leaf from the rears too...

[UNO_RACING]

By removing a spring will I have lift problems. I'm running 35" tires and I don't want to have anymore rubbing than what I'm experiencing.

[camcruiser13]

isnt axle wrap what eats pinions, if its so stiff then i would assume no wrap and failure was caused by something else? idont know food for thought

[ranger]

Your friend is full of crap.........

[vfrer]

My 4" HFS flexes really well and I love the ride. No issues with wheel hop or anything like that when wheeling (mostly stock, 32's, locked in the rear). My shackles move very freely and actually are the limiting factor of my flex... the cross beam on the "H" style shackle hits the spring perches. I have about 6000 miles on them now and 5 or 6 wheeling trips. My only gripe is that stupid leveler block on the passenger rear spring... It caused my 40 to lean. Need to get back in there and tear it out. Probably do a U-bolt flip too as the spring pack is thick and hangs too low.

Drive around with some weight in the back to break them in some more. They do look thick and beefy but I think they flex well. Also just hop on the bumpers and bounce and see if your shackles move, should have some movement just from that. If your shackle bolts are too tight that could contribute.

Eric

[dgangle]

Originally Posted by ranger

Your friend is full of crap.........

That's what I think too. Soft, flexy springs are the one's that contribute to broken pinions, not the reverse.

The only ways of softening it up really are to 1. remove leaves 2. add weight or 3. relocate the rear spring hanger forward to increase shackle angle (assuming it's vertical or near it now). But then you have lift issues. You cannot have both. Either live with the ride or reduced clearance or buy smaller tires. 4" SUA will fit 35's but don't leave much leeway in the form of clearance. All springs will sag when they soften, it's just some do it sooner than others.

I am not saying they are wrong, but you may have to reevaluate your priorities.

[FJ40zen]

I say, Booshit! too. Although there may be lots of leaves in the pack, they flex very well for leaf springs. Heck, I can hit my stock bump stops sometimes. They don't ride like a car or a gooshy pickup, but they are not stiff. If they are, you have shackle angle problems or they have not been flexed enough. They may need to be flexed a few times on the trail. Criss-Cross a ditch a few times on an angle and let the axles droop for a few minutes each time. Do you have any pictures of your shackle angle on level ground?

Don't let your axles hop!! Hit the clutch!

[Spud]

With one leaf removed in front and running 33's, It does rub sometimes if I get it crossed up. Not too major rub, but rubbing none the less.

I dont recall any rub in the back...again I have all leaves still in place in the rear.

[Pin_Head]

Originally Posted by ranger

Your friend is full of crap.........

Sad, but true.


The center pin ejecting from your carrier is a freak occurance that is not related to wheel hop or spring wrap. Just get another differential and get on your way.

[UNO_RACING]

Originally Posted by FJ40zen

Don't let your axles hop!! Hit the clutch!

I need to take a lesson in 4x4ing.

When the pinion borke it seemed that the truck was slipping at the crest of the hill. I wanted to make it up, so I put the hammer down and the truck bounced---that's when I heard the pin broke. I make it up the hill though.

In terms of my shackle angle, it's actually really good and they flex too.

[Poser]

Originally Posted by UNO_RACING

I need to take a lesson in 4x4ing.

Ding ding!



Anything can be broken when beat on enough.

Originally Posted by UNO_RACING

When the pinion borke it seemed that the truck was slipping at the crest of the hill. I wanted to make it up, so I put the hammer down and the truck bounced---that's when I heard the pin break. I make it up the hill though.

Don't drive like an asshole, and you won't scatter parts.



Things can get really expensive when you allow your ego and testosterone to make driving decisions for you.


You will figure it out, or go bankrupt paying for all those life college credits.



Oh, and your friend is full of shit.

[UNO_RACING]

Thanks for the feedback.

So by upgrading to the fine spline and the detroit locker I should have better climbing capabiliites, right?---I'll take it easy on the throttle.

When I broke, I wasn't off road, per sey, but in an area where they are creating a large man made arroyo. I would never drive like a bung hole in on trails because of the errosion potential; and the potential for breaking far from home.

[Poser]

The Detroit will help with traction, but again, if you drive like an asshole, you can/will break anything.


Yes the fine spline pinion is stronger than a coarse spline component, but in the end, it is not going to make the difference between being running or broken in the event that you subject the pinion to a binding situation, which is why pinions fail.


You STILL have not posted up any pictures of your broken junk.

[bsmith123]

Live and learn

Lets face it at some point we have all stuck the pedal down for the fun of it and no harm done if in the right place

I have the HFS but am still building but without a top or any accessories it does feel a bit stiff--I kinda like a truck feel anyway so I don't mind but I do plan to put some weight in and try and wear em in a little.

Proper shackle install and grease should help I would think

I've also heard of people putting grease between leave or using teflon.