Ok Chris. I will send you a seized VC--I'll even pay for the shipping.
Put it in your rig and see how far down the road you get.
Report back.
Dude,
Chris doesn't get far down the road when everything is WORKING on his truck.
VC = Viscous Coupler Caused Damage
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Dude,
Chris doesn't get far down the road when everything is WORKING on his truck.
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Beno can verify but it was like $1200-$1300. I got his used one at a discount. I was going to no NO VC.
https://forum.ih8mud.com/80-series-tech/124794-tutorial-removing-viscous-coupler-photos.html
But seeing as how this is my winter DD and we have a lot of slopy days after snows I thought a VC might be a good idea.
https://forum.ih8mud.com/80-series-tech/124794-tutorial-removing-viscous-coupler-photos.html
But seeing as how this is my winter DD and we have a lot of slopy days after snows I thought a VC might be a good idea.
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Why did the carrier need to be replaced?
I agree that the locked VC was a contributor, but my bet is it wasn't the root cause of the diff problem. There have been way too many run locked for for way too long without damage.
In my observation, most diffs with issues have poor fluid change in common. The fluid has two main functions, lube and cooling. A fleet rag had an article on diff additives, they ran a clear diff cover and temp sensor to monitor ring gear temp. When running additives that thickened the fluid, they noted much higher gear temps. With the thicker fluid, they found much more fluid foaming, and less fluid to gear contact. The fluid cools by contacting the gear and carrying/transferring the heat to the housing. Air entrapment/foam is a good insulator, reducing heat carrying ability. It also thickens the fluid, making it more likely to stay"flung away" from the gears, so less gear contact.
Lucas gear oil additive was one of the worst in the test. This is why I wont run it, but not blaming it on your problem, my guess is it was added after the problem started.
More specific to the '80 series is moly migrating from the knuckles. Most "normal" owners don't change gear oil, check breathers, etc, leading to excessive moly in the gear oil. Grease is a great thickener, I have seen '80 front axles where the black "oil" took forever to drain, have checked level after a run and found the housing full of thick foam. This will cause big time gear/bearing heating and greatly reduced lubrication. All of the '80 diffs that I have seen failed, ether had this issue when failed or in their immediate history.
Obviously I can't see your rig, but my guess is your failure was a combination of problems. The fluid maybe be original from the factory, may have had a plugged breather, the fluid was thick with moly, causing bearing and/or gear wear problem(s). This caused the whine, a whine is telling you that the gears and/or bearing(s) are not happy and there will be failure if not addressed. The added load from the locked VC didn't help, but my guess wasn't the root problem.
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If you have ever wheeled in a place like Moab, the slick rock has very high traction, my guess higher than pavement. I have many times and seen plenty of others spin all 4 tires, fully locked on slick rock. Mine has 37" tires, so guessing that the forces would be much higher doing this than simply driving locked on pavement. If the '80 parts were so weak that, locked use on high traction surfaces would cause part failure, wheeling at places like Moab would be impossible. Every year many '80's do it and breakage is rare.
Agree.
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The oil coming out was dark but the consistency was that of oil and not moly grease. I pulled the fill plug first and very little oil came out so it was the right ammount. It could have been origional oil didn't have records of maintenance. I didn't get to see the carrier my buddy(Toyota Tech) who did the swap took the core in and swaped for another good one. He said it was bad, that's all I know about the carrier. I have a box full of bearings and gaskets and such from the swap and knucle rebuild.
What causes the VC to lock up? Seems odd........
Wrench
One Bashed Up 80
Useless post. FAIL!
Spinning all four tires while fully locked would indicate low traction, not high. Plus the name itself (slick rock) would indicate the same.
That'd be the opposite of pavement. Pavement is where the tire has enough traction that it can't/won't spin, causing drive train windup and increasing the chance of breaking something if locked. Slick rock allowing tires to spin easily would eliminate drive train windup, meaning very little chance of breaking something (at least due to that particular cause).
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You have obviously never been to Moab. The name "slick rock" was given a long time ago, for steel covered wagon wheels and steel horse shoes it was reported to be slick. It's solid sandstone, where/when it's clean it has fantastic traction for rubber tires, similar to course sandpaper. Yes rigs get very bound up, turning sharp and/or blipping the throttle causes tire(s) to slip/spin temporally releasing the bind. This is accompanied by loud tire barks, this is referred to as Moab seals barking.
If you have never experienced it, at least watch some Moab videos, when there are a lot of rigs working on slick rock obstacles there will be almost constant barking. I test my lockers before most every trip in the parking lot and find it much easier to bark the tires on pavement than Moab slick rock.
Even assuming all that is true, I've never spun 4 tires on pavement. Nor do I think anyone is doing 65 mph on slick rock.
Even if slick rock is far grippier than pavement, it's still an apples to oranges comparison. It'd be like saying "I've never rolled my Cruiser by cranking the wheel over as hard as I can....at 5 MPH."
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The fact is you don't know what has been done to it? The PO could have heard/felt a noise and had the diff fluid changed before he sold it? When the diff fluid is heavily contaminated, the new fluid will turn gray/black pretty much immediately, it takes a couple of changes flush the moly out. Not saying this is what happened to your rig, but is a possibility.
I have worked on several rigs with locked VC and only one had diff issues, but it had lots of other maintenance issues, including heavily contaminated gear oil. Another that I helped with lately is a DD, has had a locked VC for a long time, developed a front pinion seal leak and needed axles resealed. The diffs were removed, had low/no pinion and carrier bearing preload. We disassembled them, everything looked great, got new seals and crush sleeves, reassembled with proper preload. They run quiet, have never made any noise, even with the locked VC.
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It's true, come to Cruise Moab next year, sign up for some 7+ trails and we will have some big fun, trust me, what could possibly go wrong?
Nor do I think anyone is doing 65 mph on slick rock.
Even if slick rock is far grippier than pavement, it's still an apples to oranges comparison. It'd be like saying "I've never rolled my Cruiser by cranking the wheel over as hard as I can....at 5 MPH."
Exactly my point. The subject is diff strength, most diffs are broken when wheeling, with good reason. The torque loads on a diff are orders of magnitude higher when wheeling in low range than when cruising in high gear. A diff that can take off road abuse, will be almost impossible to break on the street, in high range. The one exception would be heating, but this is a rare failure, not common in Cruiser diffs, the only time where I have seen it was very contaminated fluid.
I plead the 5th on the "doing 65 mph on slick rock" thing.
I'm not sure why it hasn't been mentioned but what's the nasty grease goo and rust on the pinion gear and pinion shaft?
I realize a seized V would put you in a constant state of 4WD but it wasn't that long ago many trucks were sold new with full time 4WD and those trucks didn't have major drama. I agree with Kevin, there was something else going on and the seized VC was the icing on the cake to cause breakage.
I realize a seized V would put you in a constant state of 4WD but it wasn't that long ago many trucks were sold new with full time 4WD and those trucks didn't have major drama. I agree with Kevin, there was something else going on and the seized VC was the icing on the cake to cause breakage.
Wrench
One Bashed Up 80
Yeah I saw that. It looks like it got super hot due to poor oil visc. Basically caramelizing the oil and whatever else was in the oil to it.
Anything with permanant 4WD (really AWD) has a center differential that is NOT locked. Or has some kind of mechanism to vary the front rear power distribution. A siezed VC would lock the front and rear axles so that they could not turn indepedently.
In a turn, something has to give...period. If you're lucky that give is in the tires, slipping, chirping, etc. If the tires cannot slip, something will break, depending on how much give or slack there is the in the drivetrain and how tight the turn is...and in this case (maybe)...how weak the drive train is due to wear or other damage.
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All the parts, bearings etc. from the birf job and the gear job were put in a box so alot of contamination happened after everything was taken apart.
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If you going to wheel even moderately aggressively on rock, it happens. The first video is of a step on Zuki Hill, it is a long complex of climbs/obstacles. With a big group there is often rigs working many obstacles at once, so a din of seals barking. The video makes it look flat, the pic does a better job of showing the climb that the ledge is on, where the yellow FJC is.
The second video is some obstacles with seals barking. Often, once an obstacle is cleared there is nothing but an expanse of slick rock, so to unlock you have to rock the steering wheel, blip the throttle, bark the tires to relieve the bind. This becomes second nature, when you have done this, the whole "never lock on high traction surfaces or you will break something" argument becomes
. YouTube - shannonburchardi's Channel
YouTube - Wedgie and Golden Crack- Cruise Moab 2010
If you going to wheel even moderately aggressively on rock, it happens. The first video is of a step on Zuki Hill, it is a long complex of climbs/obstacles. With a big group there is often rigs working many obstacles at once, so a din of seals barking. The video makes it look flat, the pic does a better job of showing the climb that the ledge is on, where the yellow FJC is.
The second video is some obstacles with seals barking. Often, once an obstacle is cleared there is nothing but an expanse of slick rock, so to unlock you have to rock the steering wheel, blip the throttle, bark the tires to relieve the bind. This becomes second nature, when you have done this, the whole "never lock on high traction surfaces or you will break something" argument becomes
I'd still say that is fairly slick rock (no pun intended). Either that or they have their tire pressure way too high. (Which they do look high in the video, but hard to tell.)
But I'm used to wheeling on mostly granite rock. The second video shows it well, the sandstone has been worn very smooth. Granite doesn't wear smooth like that, it tends to flake off or break. In this area, if you're spinning the tires like that you've lost traction. This could be due to being stuck, high centered, tires in a hole, PSI too high, or a layer of super fine dust sitting on the rock (makes it about as slick as ice).
You never spin tires like that due to too much traction. At least not where I wheel.
