4Hi binding on pavement

So I have the needle bearing issue with my truck so I was on a straight away and engaged 4hi to stop the vibrations and forgot to go back to 2wd before hand. I took a 90 degree turn going left and my truck binded into a complete stop. I was able to get back to 2wd and go to a parking lot and look at everything. My question is how screwed am I regarding front differential damage?

 

If you didn't hear anything go pop or bang your probably fine just don't make a habit of turning sharp in 4wd on a hard surface as it's very hard on driveline components.

 

If it were me, I'd drain the fluid and see if you have any metal chunks. If there are no metal chunks, then I'd change the fluid with fresh diff fluid, and get the needle bearing replaced. The only other option is to remove the front diff, disassemble and inspect it visually and with a dial indicator, to make sure it's within factory specs for runout, etc. Fluid inspection is the easiest. If you have chunks of metal, it's probably easier to buy a new front diff, do an overhaul, and replace your existing one. Worst case, drain the front diff, pull the cv axles and drive it as a 2wd until you can rebuild a replacement, then swap out.

 

You’re fine…don’t do it again though lol

 

And thirded. Don't over think this one.

 

Time to part it out!



Or not.

 

Yeah, it definitely was an accident.

You mean parts out and twin I beam in right?

 

The damage would be in the tcase if anything not the front diff. But agreed as long as its fine now no need to investigate further.

You mean Twin traction Beam?

 

Just put it in 4wd again on a straight and listen for clicky chunky sounds. If it’s quiet and smooth, no worries. The differential will tell you if you messed something up.

If you do end up draining it, don’t be worried if you find a few small pieces of metal, especially if you’ve never changed the fluid up to this point. It just matters whether the diff is smooth and quiet when engaged.

If you haven’t ever changed the fluid, it’s easy, and is a good idea to go ahead and do it. The diff gears shed the most metal in the first 1,000 miles of engagement as they’re breaking in.

Just make sure you use a digital torque wrench to tighten the drain plug; they easily strip. You can also replace the drain plug with the Lexus version, which has a male hex head instead of a 10mm allen keyhole, so it doesn’t strip as easily.

 

know the part # on that lexus plug?

 

I’ve seen plenty of diffs destroyed; haven’t heard of a T-case being damaged by binding before. Is this common?

At any rate, I would expect CV axles to go before the front diff, and the U-joints to go before the T-case.

OP, for what it’s worth, people drive in 4x4 on so-called “slick rock” in Moab all the time, which is just about as grippy as pavement. I do it with an autolocker in my front diff. Binding is not uncommon, and typically doesn’t result in damage unless you gas it hard to break the bind.

 

Common not sure, but if you think about it the binding is happening in the tcase. When turning the front driveshaft needs to spin faster than the rear and cannot. There shouldnt be any binding between the left and right wheels assuming it not a locked diff

I guess if the tcase is strong enough then it might transfer the load to the front then that would be the weakest link

 

The outside wheels also turn in a bigger radius than the inside wheels and that's where stress at the diff happens

 

Its an unlocked diff..... Its kinda the point of them. To have a differential in wheel speed.

 

Here you go:

https://ebay.us/m/UgeG5Z

Or go nuclear on it and weld a ratchet socket onto the OE drain plug. It’s the only thing that 100% will not strip.

 

The binding happens along the full length of the drivetrain. In the case of open front and rear diffs, the binding occurs from the rear tire with the least grip to the front tire with the least grip. The weakest link breaks first.

The weakest length is usually the traction of the tires. Then the CV’s. Then probably one of the differentials.

The torque exerted on all the components downstream of the transfer case is much higher, because the t-case reduces the drive ratio. The torque exerted on the axle shafts is higher still, because of the drive reduction in the third members. The planetary gears in the t-case are pretty stout.

 

Fair you got a point, the diffs themselves don't bind was my whole point. Both are open means no binding there( left vs right wheel). Its the speed differential between the front and rear driveshafts that's the issue

 

I meant this lol

 

The damage is cumulative. You rarely have a catastrophic failure, but it can happen. If you were in enough of a bind that the truck stopped moving you did some damage. It may not show up for years but internal components were stressed beyond what they were designed for.

The real damage was probably to the chain in the transfer case. If it is overstressed, it stretches. Letting things like this happen repeatedly it will eventually let the chain stretch enough that it will start slipping on the gears.