I want to improve my FJ40's water crossing problems. Ive extended breathers and eventually will install a snorkel but Im working from the bottom up. TPI tells me they can sell me a pretty much water tite distributor/wires. What about the alternator? What happens when it is submerged or sprayed? All input is welcomed, Im learning as I go....J

I don't know of anyone who makes a sealed/waterproof alternator. Alternators run hot under load and require lots of air circulation to keep them cooled down.

I've done a few deep water crossings (deep enough to soak the stereo in the dash), but I haven't had any alternator problems as a result. Perhaps the speed at which the alternator turns causes enough cavitation to prevent it from getting too soaked to work.

I used to run a Mallory marine distributor and cap (marine caps are blue, and come with an o ring) on the SBC (salvaged from a Land Cruiser) that I ran in my Blazer. That, and a homemade snorkel kept it running in water deep enough to come around the windshield.

if it's just water i wouldn't worry about it, if it's sloppy mud slop water gunk then you might have issues, best bet is to mount it high, and hose it clean as soon as you get through the brown gook.

Great advice, how do I go about finding a GOOD marine distrib. that will work in my FJ40? Or do I just buy an FJ40 dist. and add the o-ring or is there more to it than just a blue top and an O-ring?

I wouldn't worry about it- never had a water Xing related problem with an alternator. The diodes get pretty hot, so I imagine dunking hot diodes in cold water *could* mess them up. The bearings and slip-rings are the only real "wearable" parts and they'll tolerate some water just fine. I've accidentally hit my alternator a few times with the pressure washer, so I can confirm that. By the time it would really be an issue I'd be more worried about freezing my nuts off. :eek:

On the subject of electrical parts, make sure your starter has adequate drains and it should be OK, muddy water shortens their life somewhat, but there really isn't a cost effective alternative, other than just replacing them a bit more often. Just buy a starter that comes with a lifetime warranty. I wasn't sure if you could restart an engine if the starter was completely submerged - I tried it - you can (at least on a small block chev). :D Some people give 'em a squirt of WD-40 once they're back on dry ground to help get the water out.

If your fan-to-radiator clearance is close, build a guard in case the fan decides it wants to eat the radiator. Ask anyone that runs demolition derby cars, and they can give you some pointers on design. You can limp home without a fan, but it's really hard to limp home with a foot-long gash in your radiator. Fans will usually survive a fair amout of abuse unless you enter the water "Dukes of Hazzard" style.

Most places I wheel, deep water crossings aren't necessary, so I simply avoid them. You can call me a puss, but after wasting an entire afternoon changing gear oil in two diffs/transfer case/repacking the hubs/greasing U-joints/pulling mud & pond muck "floaty things" out of my cab, there really isn't much enjoyment to be had from crossing streams in the long run. Keep in mind, you might have to do all of the above several times before you get clean oil.

Once you start getting into stuff that actually requires a roof-height snorkel - you're better off just buying a boat IMHO. Also, Make sure you have all 4 screws in your front license plate or the "wake" splashing on your front bumper will peel it right off - ask me how I know :shaking:.