Sunk my rear end for about 10 minutes... how urgent is a rear diff fluid change?

Just pull the fill plug and dip your finger in the oil like said. Why make a big deal out of changing it if it is clean? Sure change it when you can to be safe but if you drove it more than a mile it is going to be mixed and have a hazy milk look to it or be full on mud colored so it should be obvious.

 

Grandmas been around long enough to know you don't go into a water filled mud pit without some extended breathers and not wait 3 weeks to do a simple lube job.

 

I'm always curious why we don't see more diff failures if this is the case, how many trucks are used to launch boats dozens of times a year? Are these people adding diff breathers or checking their fluid after every launch? I seriously doubt it.

 

I think very few people submerge their diff when launching. I’ve been launching my various boats for 50 years and never submerged the diff. Actually one time I did but I was launching from shore and not a launch ramp. Wheels went in a hole and the back of the truck was pretty deep. It was an old Ford, nothing affected that truck.

 

It's more of a possibility than a high probability. The physics of it are definitely true. The negative pressure needs to exceed the axle seals, how hot the diff is to start and the temperature it cools to are the variables that need to be just right to create enough vacuum.

 

You'll be fine till you can flush it. Let us know if you find any evidence of water when you get around to it

 

https://www.ebay.com/itm/405717442222

These come in handyfor differential fluid and transfer case oil changes .

 

Just a bit of friendly advice- if your 4wd doesn’t engage anymore in a couple weeks, check the transfer case actuator - it may have flooded from the fun and its internal parts are corroded.

 

Good way to trash the rear drums there. Clean them thoroughly asap.

 

How is that going to trash the rear drums? The mud and water will drain out and they will be fine.

 

Dirt and pebbles will make their way inside the drum and scuff up the shoes and score the drums.

 

Yeah thats a really good point. Happened to me once. Water and some of the mud will drain out, but a ton of fines and grit will be left behind. A ton. Ask me how I know

 

Good Lord, some of you talk like these trucks are made from paper mâché and will disintegrate if used for it's intended purpose! Get out there and get muddy! And if something gets mucked up because of it, then you fix it!

I pretty much just described my childhood where we slowly destroyed my FJ-55 Landcruiser during my high school years. We beat the ever-loving shit out of that vehicle on a daily basis and had the great time doing it. And when something broke from all that abuse, we fixed it and headed right back out to those muddy trails.

 

Older vehicles were much more resilient and repairable
Just sayin'

 

Is this just your opinion or can you back that statement up with some facts / data?

Just sayin"

 

Right! My first was a 97 Tacoma I got practically new when I was in high school. I went out of my way to drive through streams and rivers. Mud, whatever we were up to and I would clean it up once done. Did regular maintainence but never once would consider diff fluids or any of that. I once happened into one of the Jeep camps that Jeep used to host. I was inebriated and it was after it had "closed" for the day but I arrived with a Jeep owner I knew who was camping. I woke up the next morning under my truck with people walking by and jeeps crawling through this course barely moving. People were like "hey man, you are alive. You are crazy." My buddy was like man you went through that course in 3rd gear last night. Jumping shit. I can't believe you didn't destroy your truck. I was like, well shit. I do not remember that but everything looks fine. Got in and drove away and never thought about it again. Sold that truck with almost 200K on it and it ran as good as the day I bought it.

 

Probably not that many launching boats because you need HP to tow a boat! LOL... I joke, I joke.

 

As some one who repairs her own vehicles
I have a lot of hands on experience that had proven this is a fact..

What I wouldn't give for my 97 BMW
Or my 97 Civic back
Both were tanks compared to my newer vehicles
And simple to repair as well (tho they needed a lot less repairs/attention)


But really, we all know this is a fact..
New shit isn't meant to last
All manufacturers have gone the way of - if we make it like shit, then people will buy more of our shit

I have a 25 yr old washer/dryer - same deal as the old cars; I can fix either one with 20$ and an afternoon.
Can't do that with new models..

 

Diffs and brakes are the same as they were 40 years ago. If the brake starts making a noise take the drum off and check it. If the diff oil looks like it has water change it. But pulling things apart just to make sure they look okay just because you drove through some mud and water is crazy to me. Growing up in the country driving your truck through the mud is what you did for fun. A lot of farmers drive through mud and dirt for miles daily. These trucks are way tougher than they are being given credit for.