MGM Submarine -- what to check?

[chester4Run]

SE FL got some serious rain over the past couple days and I had to drive in it. I was in water up to 2.5 feet deep, and got hit by waves from oncoming trucks that took that up over the hood. I had to navigate through several flooded sections of road, probably about a mile in total. The truck had no issues, and continues to start and run fine. I checked the airbox and it was wet, but had no water in it. Engine oil appears fine as well. I need to drive it this week. The bottom is pretty filthy with debris. Here's my plan, and I'm looking for any additional suggestions:

- Pull the skids and clean debris off everything (hose it all down).
- lube chassis -- I have zerks on UCA, LBJ, and drive shafts.
- change diff oil F&R
- check brakes (just look them over and check for issues). These were not hot going in, so should be fine.

 

[02SE]

First on my list I'd check the transmission fluid for signs of water contamination, ASAP. If water contamination is found, don't continue to drive it. Have it towed to get the transmission fluid flushed completely. Water in the transmission will destroy it in short order.

Then I'd check the T-case, and change the gear oil in it.

If water got into the passenger compartment, I'd be pulling the carpet and checking all electrical connectors for water. If water is found, start drying everything.

 

[chester4Run]

It's sitting in the garage today with the windows all open because it smells damp. Carpets feel dry under the mats. I'll add Tcase and Trans to the list. I checked out the bottom and the only damage appears to be a strip of foam that washed back from up front.

Thanks!

 

[Humble Leader]

so some thoughts for you from someone who has offroaded and went too deep into water

- the vehicle has breathers for front diff and transmission that go into the engine bay. so you're probably OK. the rear diff has a breather but it wouldnt hurt to change the rear diff fluid if you're due because that breather doesn't route to high ground in the engine bay. the 4runner can be driven through deep water despite what everyone tells you
- if you are smelling damp in the vehicle water may have gotten under the carpet and has soaked the jute backing. I would recommend you pull the carpet up and inspect. if the jute is wet, just remove it and let he rest of the carpet dry. then you can place higher quality foam back under the carpet. jute absorbs a lot of water. trying to dry it is not going to work
- I removed all my jute backing and didnt have to remove any seats. would have made my life a bit easier and resulted in less bloody knuckles, but I got the job done
- I spent about 3 hrs in deep water, and even got stuck at one point. I changed the rear diff fluid and it was perfectly clean. I had just changed it maybe a year ago too. obv Im one data point but sinking the rear diff wont destroy your vehicle 19/20 times

 

[chester4Run]

Thanks! I'll prioritize the rear diff and trans for fluid changes. Neither are due yet, but my amsoil arrived today so I'm ready to go. I'll pull up the carpet tonight and see what's going on. Maybe I'll pull the seats and do a deep clean while I'm at it. If the schools stay closed I can keep using my wife's car this week.

 

[El Dusty]

+1 for All of your drivetrain components that have breathers being checked for water ingress. When you car comes up to temp and cools off the fluids heat and cool, pressure needs to escape when things heat up and return to normal as things cool down. The risk you run driving in to high water is the rapid cooling of your drivetrain as it comes down from operating temps by the colder water temp. This creates negative pressure inside your diffs, trans and t-case which will suck air and water in to the breathers depending on if they are submerged.

 

[02SE]

so some thoughts for you from someone who has offroaded and went too deep into water

- the vehicle has breathers for front diff and transmission that go into the engine bay. so you're probably OK. the rear diff has a breather but it wouldnt hurt to change the rear diff fluid if you're due because that breather doesn't route to high ground in the engine bay. the 4runner can be driven through deep water despite what everyone tells you
- if you are smelling damp in the vehicle water may have gotten under the carpet and has soaked the jute backing. I would recommend you pull the carpet up and inspect. if the jute is wet, just remove it and let he rest of the carpet dry. then you can place higher quality foam back under the carpet. jute absorbs a lot of water. trying to dry it is not going to work
- I removed all my jute backing and didnt have to remove any seats. would have made my life a bit easier and resulted in less bloody knuckles, but I got the job done
- I spent about 3 hrs in deep water, and even got stuck at one point. I changed the rear diff fluid and it was perfectly clean. I had just changed it maybe a year ago too. obv Im one data point but sinking the rear diff wont destroy your vehicle 19/20 times

Yes, hopefully no water got into the drivetrain, but the first thing to do is to confirm whether or not they suffered water ingress. The diffs and T-case can tolerate water getting in them better than the transmission can.

Back in the days of being a Master Tech, flood cars were the worst. The problems flooded cars can experience ranges from the immediate, to possibly months down the road when electrical connectors/ECU's/ BCM's/etc. that got wet, and went undetected, corrode to the point of no longer conducting electricity.

All those problems can get really expensive to diagnose and fix, which is why insurance usually totals flood cars.

 

[chester4Run]

That's a good reminder @02SE. I'll get some QD and clean any low-lying electrical connections while I have the skids off.

 

[4RunnerAquasport]

That's a good reminder @02SE. I'll get some QD and clean any low-lying electrical connections while I have the skids off.

60 years in Brevard county, flood events are common, but the Melbourne/Palm Bay area was the worst Ive ever seen. One note on electrical, after you clean the connections, put some dielectric grease in all of them. This won't be the last time you see high water in this state and the dielectric will help to keep the water out next time. Might want to pull the carpet to sit in the Sun and put some fans inside the truck, if you discover anything wet in there. Some tubs of damp rid might help also.