Hit Water at Highway Speed

Hey all, new here.
In short, the highway in my town had horrific flooding that wasn’t visible until there was no time for corrective actions.
I hit the puddle at roughly 60 mph.
Puddle doesn’t really accurately describe the body of water. It was a solid 8 inches deep.
My truck felt like it hit a brick wall. It slammed to stop. I’m amazed the airbags didn’t deploy.
Limped it off the road.
No engine stalling.
No visible damage after I crawled around/under it.

Now it’s making a loud grinding noise (almost like the sound of plastic dragging under the truck) at low speed in first gear.
It doesn’t make the sound in reverse, at higher speeds, or while idling.

My suspicion is water intrusion in the rear differential compartment.

I don’t have the setup to investigate myself, and it needs to be road trip worthy in three weeks, so off to a mechanic I go.

Anyone have any other ideas that could be causing that noise?

Update: spent over an hour with the truck jacked up grabbing at every piece of shielding I could reach to see if anything was loose, bent, etc. Nothing looks out of whack.

I had a my friend help me pinpoint the noise source as best we could.

It’s 100% coming from the back undercarriage.

It literally only occurs going straight forward at low speed, not effected by wheel turning.

Absolutely zero sound when reversing at any speed.

It’s not louder on one particular side, and sound like it’s in the dead center, right around the middle of the rear axel.

Mechanic isn’t open till tomorrow, so until I head there, anyone wanna try and make another guess!

 

I’d say it more likely some skid plate or plastic shroud got bent and is dragging on something.

check the metal guards around the front disc brakes. They bend easy and hit the brake disc

Iv hit my fair share of puddles at speed and folded many license plates, stock skids, plastic fan shrouds… hasn’t ever been anything major

 

Most likely a broken/loose plastic part.
Post some photos of the under side of the front of the truck.

 

Check the motor fan in front of the engine for damage...hitting water at high speed can really mangle the plastic fan

 

It sounds like something relatively benign. Don’t let your head get the best of you. I highly doubt your rear differential was damaged by high pressure water.

I also once hit a puddle on a flooded freeway at 60ish mph. Wow, the deceleration was intense. The car was fine for years afterward.

I’ll bet you will avoid similar situations the rear of your life. Low lying areas during it shortly after heavy rain can be dangerous. They are generally easy to identify though

 

At 60 mph, there was no time for water intrusion in your differential! Something probably got bent or broke loose.

 

Not to mention that water intrusion into the diff does not cause immediate damage. It would take some serious water pressure to damage steel gears. Titanic levels?

 

There are many pieces of heat shielding around the exhaust pipes and catalytic converters. They are press formed out of paper thin aluminum sheets. Check all of them.

 

Fortunately people dunk Tacomas in deeper water all the time when off roading, so there's a wealth of experience here.

Most likely one of the plastic pieces in the front fenderwell had come loose and is rubbing on something.

Leading edge of fuel tank scatter shield could also be bent and rubbing on driveshaft. It's easy enough to bend back or cut off with tin snips.

 

Check by fuel tank. There is a shield between fuel tank and drive shaft, that bends easily. It will come in contact with drice shaft.

 

Be glad it didn’t cause an accident and you were not hurt. It’s probably something simple a good mechanic will sort it out quickly and you can be safely on your upcoming road trip.

 

Thanks for the suggestions and info everyone! Definitely puts my mind at ease a bit.
Gonna crawl underneath it tomorrow and see if anything is horridly bent or loose.
If I can’t find anything obvious, I’ll just bring it the local shop and see if they can find the source of the noise.

 

Can you hit the puddle in reverse at the same speed? Maybe reverse the damage?

 

I dont know about from water pressure but your front brake rotor backing plates can get bent & rub on the backside of your brake rotors..
so when wheels are turning, you here a scraping sound.
also pop the hood while making the noise, make sure it not coming from any of your belts, they can get squeaky when theyre wet...

As stated, be grateful you didnt lunch your engine...
going through deep water, it can get into the engine through the air intake & hydrolock / destroy your engine...

 

Update: spent over an hour with the truck jacked up grabbing at every piece of shielding I could reach to see if anything was loose, bent, etc. Nothing looks out of whack.

I had a my friend help me pinpoint the noise source as best we could.

It’s 100% coming from the back undercarriage.

It literally only occurs going straight forward at low speed, not effected by wheel turning.

Absolutely zero sound when reversing at any speed.

It’s not louder on one particular side, and sound like it’s in the dead center, right around the middle of the rear axel.

Mechanic isn’t open till tomorrow, so until I head there, anyone wanna try and make another guess!

 

It sure seems like it would be something simple at least hopefully it’ll end up being simple, looking forward to hearing what your mechanic says

 

Maybe a rock or rocks inside the brake drum?

 

Maybe the water pressure bent the rear pinion seal debris guard. I had this happen rock crawling. The guard then rubs on the diff housing with each driveshaft revolution. Once you get up to speed, the sound gets lost in the tire road noise.

 

I'm sure that you did, but just in case, did you look at the front right corner of the gas tank? The front end of the metallic shield can get bent into the driveshaft spline accordion boot. It will slice that accordion boot. Good recommendation to just get rid of that cantilevered section. Mine did slice the boot but it was a simple fix with some self-sealing tape.

I do not see this making noise, but it might in some cases?

Here's a post about it:

https://www.tacomaworld.com/threads/drive-shaft-boot-torn.825366/#post-29595752

This part does the cutting. Kind of odd that there are marks on this one but no evidence of being bent.

 

This is a good reason to invest in taller tires (33" pizza cutters). You're Taco will get you through just about anything, with gobs of ground clearance...