Uhhh......this is not good.

[brute4c]

The fording system on the trucks helps to keep water out of the systems of the truck by using crankcase pressure to pressurize the transmission, tcase, axles, and brakes so that instead of water seeping in, pressure would blow out instead.

A perfect system, probably not, but would certainly help to keep water out of those items.

[Nailhead]

Guys,

Here in Colorado, I will occasionally be crossing creeks and what not.

Is there a good source for the proper plug? Thought I would ask before I go and check all the MV part sites.

Thanks. RB

I took my M37 through hood-deep water once, and had to service trans, t-case, both axles, and the front wheel bearings. I left the brakes alone, given they're a closed system, and they never gave me any trouble for it.

I did not, however, have to clean the floorboards...

[k8icu]

Well I'm going to chime in here and give my $.005 worth. It use to be $.02 but inflation and all. Anyway. If you are going to cross a creek or stream that is 8 inches or less in depth then you don't need to worry about the plug and your maintenance should be at your regular intervals. If you are in water deeper than that, say up to the cab then you will probably need to go through the drive system and replace fluids etc. If you are going to be in deep water middle of doors or higher then you need the plug and really should be using the fording kit.

Just my observations from doing this hobby for 30+ years.

[ColoradoSpringsRob]

Guys,

Here is the compiled knowledge regarding the bellhousing plug, fording kit, and servicing of fluids, etc. Let me know if I need edits and I will amend.

1. The bellhousing plug stays out unless fording water > 8" deep or so, you can likely get away without servicing fluids/brakes, unless there is a lot of grit in the water.

2. The bellhousing plug goes in if fording water > 8" but <= the rockers. You have to service everything and clean the brakes.

3. If fording deeper than the rockers, install the fording kit, and service it all.


K8ICU, I have been in the hobby for like three weeks, so your wisdom is worth quite a bit to me!

[Barrman]

You summed it up real well. Just think of basic physics. A warmed up truck moving will have all of the components warmer than ambient air temperature. Any snow melt creek you cross will cool those components down in a hurry. The cooling will cause a low air pressure inside the components. Even with good air vents. They might not be able to let enough air in fast enough.

If they can’t, then air will come in through any seal or gasket that will let it in. If that part happens to be under water. The water will come in with the air. That is why we are all suggesting oil and grease get changed out after being under water.

I was thinking brake shoes and silt. However, if the brakes are hot. Water could get in the wheel cylinders too.

I had my M715 up to the rockers for a good bit in mud and then in water trying to get the mud off during the 2006 FE. I took everything apart then to clean and went back with fresh lubricants. I haven’t been in deep anything since. Yet, a few months ago I pulled the hubs to look things over and some of that nasty Tennessee mud/silt was still in there.

Learning from that. I haven’t taken either m35 into water on purpose. I calculated it to be about $200 in lubricants and 12 hours to clean up if I ever do.

[kwai]

Drove my M35 through 3-4 foot flood waters during Harvey. My front diff had a gallon of water in it. The rears hardly had any. I think the water came in mostly through the steering knuckles. Trans and x-fer case were also dry.