BANG and grind in 4wd in Sand

[John87]

Hey All,
I probably should have posted and introduced myself long ago, but just been lurking since 2013. I'm the original owner of a 2014 Screw with 68k miles. It's been put through the paces with plenty of dirt miles together with rather meticulous maintenance.

So yesterday on the way home from SoCal I stopped to play at Pismo for a couple of hours. A nice enough looking guy had his rental quad completely burried trying to come out of a bowl. I pulled him out and buried all 4 tires in the process. I was in 4-high with the rear locked. After I had him free and took the strap off, I started rocking it in and out of my ruts, steering back and forth, making about 6" more progress forward each time. I've done this several times (though not recently) in the truck without experiencing anything close to what happened yesterday.

Turning about 3500 RPM, after 20-30 seconds of tires spinning, the front end would make a loud bang followed by a gear grinding noise (like trying to pull a manual transmission into gear without the clutch). As soon as this would happen, I'd let off the throttle, so it's hard to say which tire it was coming from. Safe to say, as soon as the bang would happen, the truck stopped forward progress. When I would get back on the gas, everything seemed to function as it should with all 4 tires pulling until it did it again. I repeated this process probably a good ten "bangs". I drove around for another hour in 4wd after this without it happening again or anything seeming to malfunction. At this point it seems a part is beginning to fail, and I'd like to catch it before I leave myself stranded.

Does this sound like anything y'all have gone through before? Doesn't seem like the IWE failures I've heard of others having, but maybe? Is the front Torsen on its way out? Or is one IWE gone, and is this the poor Torsen trying to compensate? I'm not scared of diving into any of it myself, I'm just hoping not to waste too much time going the wrong direction.

Thanks all in advance!


I need to update my signature, but until I do:
2014 SCREW with ICON RXT leaf springs and bump kit, and Icon 3.0 fronts. AutoFab traction bars. ADD heim UCA (soon to be Camburg). 37" KO2s on Icon wheels. 4.56 gears. RPG Tie Rods. Forged Offroad bed brace. Foutz skid plates and LCA slot delete plates. SVC tune with Pedal Commander. Lee Power Steering.

 

[Dane]

It sounds like your IWE. It also sounds like a CV, but a CV breaks and stays broken (ask me how I know). Replace your IWEs and I'd recommend testing or replacing your vacuum lines since there's a good possibility those are what caused the failure. I had this problem many times before switching to the thicker RCV IWE ring (not one problem since).

On a side note, if you're replacing your IWE it's a great time to also replace brakes/bearings/shocks if needed - since you are already there.

 

[John87]

That would be awesome if it was only that... The male set of splines that the IWE engages to is on the CV? Or do both sides get replaced as part of the assembly? I'll definitely upgrade to the thicker RCV ones... I was contemplating eliminating them completely, but vibrations drive me crazy, so I was hesitant.

 

[Dane]

The males on the CV stay. It's the IWE that tends to get torn up from partial engagement and then fails like you are describing. I was advised against the eliminators in my climate, so I went with the thick cut ones. Getting into the IWE is the trickier part (not that tricky, just some work). Once you are there, replacing the IWE is cake, you'll see.

Tip about the thicker RCV rings. You don't get instructions, but I had to use a couple washers on my IWE bolts to gain the proper clearance to avoid engagement in 2WD. So, once you complete your install, keep your truck on the jack in 2WD (you may want to start it to get the vacuum going or use a vacuum gauge to apply vacuum and disengage the IWEs). Once this is done spin the tire. If you have axle engagement, you may have to use 1-2 washers for each of the three IWE bolts. You can carefully slip these in after you have completed your install and reassembled by removing one bolt at a time, dropping the washer accidentally three times, swearing profusely, and eventually getting the washer lined up and bolt reinstalled.