Diff Drop/Limiting Straps Question

Hey y'all, i'll try and keep this short but its been quite a long process and would like to provide every detail possible to try and get an accurate diagnosis.

Last August I installed a Wheelers 4pack + a 2" AAL. I also rebuilt my Foxs, added 700lbs springs, converted them to ext. travel and installed some Camburg UCAs (along with break lines and all that jazz). I've heard of Taco lean, but my truck is extremely stiff, and the passenger side sits TWO INCHES taller than the drivers side. Since I plan on SASing the truck eventually, I blew it off. The coilovers are set at the same height, but the driver's side leaf pack is almost as flat as my OEM leafs, while the passenger side has plenty of arch. You can also tell the front is leaning by the control arm angles.

My first trip out after the lift, I broke my spider gears and my passenger side CV up taking a pretty nasty line. I decided to install an Aussie locker, and replaced the CV with an Autozone one, since I couldn't afford an OEM after the locker. I'm an engineer, what can I say. The Aussie, even after two diff flushes (

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 Royal Purple, hardly any metal flaking) it still persisted. It also lead to serious power steering issues. I broke the Autozone CV, then three O'Riley's CVs. The second one broke when I attempted to flex up on my driver's side (down on my passenger's side, the side that keeps breaking). The third broke literally 10 feet after installing the second one, in 2wd. I looked under the truck and found a crooked differential. Fun.



We pulled the old diff but never had time to crack it open as I had to go to school the next day. The brackets and the bushings inside seemed absolutely fine. Since I was so short on time, I bit the bullet and had a professional fab shop do the work.

The truck sat for almost two months without me touching it. I drove it almost six hours today back to school in 2WD and everything was fine. I attempted to flex on my buddy's new tires (up on his passenger side so my driver's side was up, my passenger was down) and after struggling a little to grip, she starts to walk up then BANG, another CV. I'm now on #6. I never floor it off road, always crawl. I don't huck my truck or bomb over curbs.

It might be worth noting 4/6, and the less dramatic breaks, all happened because the upper three ball lookin' things came out of the buckets, obviously ripping the boots.

Now i'm trying to spit ball, and the conclusions I can come up with are:

• Something is wrong with the differential I can't see
• The leaf spring disproportion is so off, my passenger side is having to move WAY too much, causing the CV to over extend. However, despite one leaf pack being flat and the other arched, I have no idea what the problem could be. Haven't had time to pull them off yet. It is worth noting I have also blown a stock passenger break line the night I put my lift on wheeling, drivers side was flexed up, passenger down

So I was wondering if anyone had any advise moving forward. A differential drop? I've heard those cause long term driveline issues, and the truck is used almost exclusively for road trips and off roading now. The other solution might be a limiting strap to keep the CV from coming down so far? Would love what y'all have to say. Thanks!

 

Hate to say it but the UCAs allowing some more downtravel are probably what is murdering your aftermarket CVs. A diff drop won't help you much as it only lowers your CVs by a half inch or so. I mean it would help a little. I wouldn't worry about long term driveline issues considering the front DS only spins when in 4wd.

Regarding your springs, maybe they are on the wrong side and need to be swapped.

 

I think the plan right now is for sure to flip the springs. And limiting straps would solve the down travel problem yeh?

Even on flat ground the passenger CV angle is much higher than the driver's side

 

That would seem in line with your crooked diff findings. Have you been able to figure out the problem there?

Also, are your front COs set at the same height unloaded? As in they both have the same amount of threads showing? I usually have to crank the driver side a little more than the passenger to get an even ride height in the front

 

No. unfortunately, my priority right now is a test on Wednesday. Just need it solid by Saturday when I have a wheeling trip. Ordering the straps and diff drop after class though.

And yeah, the front passenger side sits higher (can even tell in the control arms) but they're at the same setting, approx 2.85". 700lbs springs

 

Hmm. Yeah usually if you have the coilovers at the same setting, one side will sit lower. You'll probably need to lower or raise the side that needs attention to level it out. 2" is obviously way off so you should swap the leafs first then adjust the COs if it's better.

 

That's the plan right now. Only issue I'm having is the suspension is so off right now I have no idea of how long of straps to order. But I need to order them soon to get them soon

 

It may be faster to see what's going on with your diff first. You may lose a lot of wheelability (it's a new word I made up) if it's not giving you a lot of travel before your CVs grenade themselves. Could be something really off with your diff that limiting straps may not even be able to help you with.

 

Get rid of the aussie locker and stop buying shit parts house cvs and the constant snappage will stop.

 

Old locked diff is already out and nothing seems wrong. New diff was inspected by professionals then installed. I'll keep the Aussie out happily if it means the CV streak stops, but I just broke one with the open diff just trying to flex the truck.

Aussie is already gone and I've broken an OEM CV. Although the shitty autozone CVs don't help the problem they're not the cause. Will have angle pics up in 5 min

 

What size tires?

 

Regular ol 285/75r16s

Drivers side:


Passenger

 

Can you take a pic showing what the inner boot looks like? It's easier to reference the CV angle by seeing if there is any fin rubbing. The driver side angle looks ok but not 100% sure.

 

For sure, give me a few minutes. Yeah, the driver's side looks ok to me, its the passenger thats rough..

 

Driver (OEM)


Passenger


Could only get pics from underneath where it's sitting now

 

I'm guessing your wheels are turned? Either way your passenger side angle is gnarly

 

Nope wheels are straight but it's parked in a dirt lot

 

Yeah I would definitely start by switching your leafs. If that reduces the lean bias then good. Then you can fine tune that passenger side coilover and crank it down some to get your angles better. Ideally you do not want the inner boot fins to rub. They're pretty sandwiched at the moment lol

 

Looking at the first page of your build thread along with this thread.... I'd say your star-crossed. I'd accept it.




















Save monnies for solid axle. Save monnies to reinforce and gusset EVERYTHING.

 

Flipped the leafs and leans about 5cm now, not bad but noticeable if you really look. CVs still at a pretty gnarly angle... gonna try and make a diff drop on Thursday I think in hopes of having her wheel-able by Saturday