Tough day on the trail- 2x CVs blown out

Did you take a look at the pictures? The rollers exceeded the cup length and popped out of the cup. The OE cup was cracked when I cleaned it up and had a good look at it. That could have been when I was trying to get off the trail and out of the way to make the repair or the reason it failed to begin with, not sure. The boot is clearly toast, the axle shafts all survived until I took an angle grinder to it so I could get home.

 

I'd move this to the long travle bs thread, personally. You're likely to get some more informed answers. My money is on binding at droop but we'll need some measurements.

 

Ok, so I think you are saying the CV joint itself pulled apart; not that the entire CV axle pulled out of the diff.

I would not have expected that, but I’ve never broken one, installed one, or taken one apart. Albeit I would expect it to have a limited range of motion.

 

After talking to CVJ here in denver where I got my remaned axles from, here is what I learned. Out of the diff end comes the cup. inside the cup are 3 rollers that live in a chase, attached to the shaft. There is nothing keeping the rollers in the cup but the relationship between the diff and the hub except the boot and the clamps. If the cv was uninstalled and we each grabbed an end, it would pull out if we were stronger than the boot and the clamps. So if there is excessive travel, longer than the rollers can handle, they pop out, destroy the boot and sometimes the cup with all the force it takes right as it pulls out. So if the internal bump in the shock is blown, it would allow for more down travel bringing the rollers to the very edge of the cup. CVs have a certain point if they articulate too much they wont turn any longer. So it either just popped out of the cup or reached the point where the cv wouldnt turn bc it was past its angle that would allow turning and then tried to turn and BOOM- CV dead.

The CV cup never left the DIFF side- luckily- take a close look at the pics and you can see the 3 rollers that should be in the cup all tangled up in the boot

 

Is that a Dirt King long travel kit you're running?

I'd really encourage upgrading to RCV axles or JD's 934 axle. A stock CV has 21 degrees of movement. Once you exceed that, you're liable to pop or break. JD Fab's allow for 28. RCV is similar.

 

believe me I would love to run RCV or JD Fab but damn are they pricey. For what I do in my truck, limit straps will most likely be what I end up doing. Good suggestions though, just out of my price range.

also not LT, standard length DK lowers.

 

UPDATE: I got the axle back from CVJ and an OE on the way, found a new OE on ebay for a good price. I figured it would be good to put an axle in it so I can try to figure out whats going on. After pulling the bluetooth axle pieces out and swapping the new one here is what I found:
Passenger side axle is about 1/4 to 3/8 off the LCA. Driver side is sitting at about an inch. I added back my limit straps back until I can truely figure out whats going on so I don't blow up another CV. I talked to a few people in the industry and they all have said similar things. Either my internals are blown on the shock or my passenger side spindle is bent. The spindle has the welded gussets and I didn't see any noticeable cracks or bends. I have spare spindles and gussets to weld in. I will weld em up on monday and see if that changes anything.

pics taken at full droop - 1/4" with the straps

 

spindles

 

That spacing can vary significantly with alignment cam bolt positioning. Are your driver and passenger side cam bolts clocked the same way?

 

I will check em out and snap some pics. I am taking it to TRU auto next week for an alignment check and let the techs poke around a bit since I am stumped

 

I'd check your alignment. That CV is way too close to that LCA and there's no way that isn't touching under load. Remember that limit straps stretch roughly 1" per 12" of strap and have an elastic effect so even if you're strapped, you're probably still hitting. Likewise as that bump fully compresses on hard hits.

The spindle looks OK but hard to tell in those shots. Agree that there's something else going on here.

 

Undo the limit straps and measure the length of exposed chrome shaft on each coilover at full droop. That'll tell you quickly if one of them is overextended.

 

Curious to know what happens with this? Give us an update after your alignment

 

I’m totally new to the Taco ownership world but man are you guys hard core! Replacing CV shafts on location.

 

Once you have done one, its really easy. for your records here are the steps:
remove wheel
remove dust cap over axle nut - pry with a screwdriver or thin pry tool
remove cotter pin and axle nut retainer cap
35 mm removes the axle nut
remove sway bar links if ya got em
under the spindle, on either side of the ball joint, remove the x2 24mm bolts
now the axle shaft will just slip out of the splines and can be set aside, resting on a bottle jack or some other support, swing it towards the front of vehicle
remove front skid plate- x 6 17mm
use a pry bar, large screwdriver or something you can get seated into the lip of the CV cup. There are detents on the front and back of every CV cup for this reason
Hit the cv cup and rotate every few hits until the cv starts to move away from the vehicle.
grab something to catch any gear oil.
grab replacement cv and get it ready to stab back into the diff
remove old cv and as quickly as possible install the new one. you will bleed less oil if you are ready to get the new one in. You can also adjust you jacks and stands to the diff is leaning away from the side you are working on.
line it up and slowly rotate until you feel the splines like up and find their seat
use the same tools and hit and rotate the CV as it reseats, hitting it towards the center of the vehicle
hit until completely seated against the diff housing
clean up drips of gear oil
grab the spindle and sleeve it back on to the new axle
tighten axle nut (35mm) 173 torqued- then axle nut retainer and cotter
tighten 24mm lower spindle nuts 118 torqued
reinstall sway bar if ya got em
lower to ground
reinstall wheel torqued to 95

done

 

sure thing, I am taking it to TRU Automotive (Denver's best off road shop) on wed and they are going to get it figured. I am stumped. Some people have been saying alignment and that very well could be the case since 4WP completely effed my alignment last time they were under there. They tightened the CAM bolt ON TOP of my cam tab gussets instead of seated between em. I took it back after I noticed and who knows if they actually aligned it after getting the bolt tab seated correctly, they said they did... but ya know... I need to learn how to do an alignment on my own.

 

With the limit straps off and at full droop I had exactly 4" of shaft exposed on both sides. When lowering to the ground the passenger side hit first every time I lifted and lowered when I was measuring and turning wheels looking to anything out of place. Shock might be okay, alignment might be bad or something else that I can't see yet.

 

nice write up! I have done CV shafts on my old Subaru and Honda sedans. Comfortably in my garage though.
Never thought of doing it on the spot. I’d have used AAA for a tow home.
But I guess if you guys are out in the middle of nowhere, you don’t have a choice. Kudos to you guys for getting that kind of job done.

 

Thats wild..

 

Limit straps. Also remember that straps will stretch.