loke

While offroading I came across a diagonal washout on a trail. I lost traction climbing out. I tried to turn so I was hitting it perpendicular but the passenger tire still was climbing out first. It wasn't really the big so I just gathered a little more momentum and hit it again. With the passenger side hitting first the suspension compressed on that side and I heard a loud bang. Investigation revealed the axle had come apart at the upper CV joint.

Although challenging, I was able to make it out of the trail in 2wd. I had a local shop replace the axle. I drove the truck home and parked it. When I came out the next day I could smell the awful odor of diff fluid. It seems the axle had pulled out the half shaft. I took it back into the shop and was told the snap ring had broke and a number of teeth were sheared off the half shaft.

The replaced the half shaft, new snap ring, new seals. I drive it back home and once again the shaft has pullout out from the differential.

I'm waiting on a call back but as you can imagine this is pretty frustrating. I'm working 60-80 a week and my truck is my daily driver. Ain't no body got time for that! I'm wondering if the forums can make any suggestions. I have a 4 inch lift. I believe it's a Pro-comp kit. Is there anything special about that with regard to the axle? What could we be missing?

BigBluePile

iTrader: (3)

What year?

loke

1986.

loke

Anyone have any ideas?

BigBluePile

iTrader: (3)

Auto or manual hubs?

Co_94_PU

iTrader: (-1)

For those of us following along in the book, in this case the half shaft is the "side gear shaft" not to be confused with the U-jointed CV shaft wiki says he means

Sounds like a worn out side gear, or somebody put the clip on backasswards in which case they might of damaged the side gear.

The procedure to install these involes a slide hammer, always a bad sign in my book ADD equiped diff is a much "better" design that doesn't involve the "if it doesn't fit force it" rule..

loke

Manual hubs.

And yeah, I'm referring to the straight shaft the comes out of the differential and bolts to the CV shaft.

BigBluePile

iTrader: (3)

Conveted hubs? Aisin or warn?

loke

The hubs are Warn.

The shop pulled everything apart and couldn't find any issues. I had them make sure to inspect the diff and the side gears but they found no issue.

The replacement CV axle was an aftermarket. I requested an OEM one be installed. The shop complied without charging me anything. The owner tells me he compared the aftermarket CV with the new OEM one and didn't see much of a difference. The only thing was that the OEM had a much softer boot. Since everything looks to be ok now and there was no other smoking gun, the only idea he had was that the stiffer boot caused a little more pulling on the half shaft and it was enough to pop it out. I find that a little hard to believe but at this point no one has any other ideas. Anyone here?

BigBluePile

iTrader: (3)

Booo warn hubs. I would make sure that the proper washers are at the hub.

loke

After blowing apart the axle for the fourth time, I took the truck into a 4x4 shop. They were familiar with the lift and quickly saw one of the lowering brackets for the front diff was broken. They ordered a new bracket and as everything was going together, they determined the front differential was shifted 1/4" towards the drivers side. They found another bracket that was bent slightly (1/4" towards dr side). I haven't looked at it yet, but I'm being told they have no idea how this could have happened without an accident. The control arms, shocks, sway bar, all mounts look fine, so there's no other sign of damage. I've owned the truck for 5 years and never had any issues, so I can't explain it either.

I've been told the shops only idea is to take everything apart, cut, weld, fabricate, etc to get the diff back to the right spot and line everything up. I'm already fed up with this truck and tons of money into this problem. Anyone have any other thoughts?

loke

Had to taxi over to the shop and got to take a look. Like I said, everything look ok. The bracket they thought might be bent looks like it might be designed that way. And it doesn't look like it would move anything much if it was straightened. All the brackets related to the lift and diff drop were replaced and the guy said they all lined up perfectly when going in. That would have to mean the frame was bent or something we're not thinking about. The Warn hubs were mentioned. Could they be related?

Here's a quick video showing the "bent" bracket. Can anyone tell me if this looks ok or bent?

Co_94_PU

iTrader: (-1)

Yeah sounds like they found the root issue. They wouldn't of bend those in production they would of moved them over if they weren't inthe right location. I'd suspect there will be an impact point on the lower P-side of the diff, but I don't know the "warn washer" issue.

The newer Pro-comp kits have a gusset plate that ties those two brackets together that gets welded across the front. Should be a relatively easy retro fit.

Here is a random CL pic you can see the plate welded across the front.

loke

Thanks, but this doesn't explain why everything else is lined up. To get the diff over I would have to move or bend the other brackets, or drill out mounting holes. It just doesn't make sense to me.

Co_94_PU

iTrader: (-1)

These aren't the best pictures but I grow bored of looking for the right angle and good lighting.



The diff is the lowest spot during compression. So when you hit the cross cut at speed with the right tire leading, the controll arm compresses and the diff is now the lowest part of the front end. So just guessing at the heights here.. If the tire is sunk into the cut 3" you only need a 3" rock to smack the diff and shift it over.

If you had the reinforcement, maybe the whole drop arm assembly would of moved, maybe the diff cracked, or maybe it would have just made an impact noise. Hard to say.

Again just a guess/opinion. Check for scuff marks on the diff?

When I am crossing a cut, railroad tracks, or speed bumps. FWIW.. Going slow I want to take it one wheel at a time, eg diagonally, this keeps the other tires as support. If I'm going to hit those same obstacles at speed I want to hit them dead straight, to spread the impact load, and tap the brakes to precompress the suspension.

Just giving one mans view point, not trying to teach you to drive or offend

loke

Any input is appreciated. No scuffs anywhere. Also, I use a pretty beefy skid from the front bumper to the lower cross member. If something hit, it would have been on the skid and then dissipated out. Even a direct hit to the cross member at the right spot wouldn't have hit near the bracket.