I went through 2-2 1/2 feet of water (I'm guessing, but it was deep and water coming over the hood) 3 seperate times and each area of of standing water was probable 20-30 yards in length. Do I need the diffs drained/refilled? How often should it be done when not going through deep water?
I'd pull the plug (make sure you can get the fill plug loose first) for a second and let a small amount drain out, and see what it looks like. If water has gotten in, the fluid will look milky. Pump back in as much as you drain out.
If you haven't extended the breathers, you may want to look at doing that mod.
If you have not extended your diff lines I would change the fluid ASAP. You can easily have a look in the filler plug to check the condition of the fluid but it is a good idea after water as deep as you describe. I know of several people that have driven across deep water in their brand new SUVs and had brand new fawked differentials within a week. I just extended my breather lines and its a good thing too because I had to drive across a flooded river last night. Passed right by a stalled minivan and got across the bridge where it was roped off on the other side. Only about 20" deep but pretty quickly moving water about 80 yards across. I love this truck more and more every day!
Extended the front breather and changed the PCV valve on Black Friday.. took all of 10 minutes....still have to do the rear breather and should be good for now..
well, I did my front breather too, way back, but seems hard to believe that there would be no water coming in from the knuckle, hub etc, and yet a lot from the breather valve...
Well, at least it'll help with the vacuum, I guess.
E
Eric,
The design of the stock breather valve creates a vacuum in the diff. When the hot axle is submerged in cold water the water can be sucked in past the axle tube seal and into the diff. The "fix" is to remove the source of the vacuum by modifying the breather valve. Most people extend their breathers at the same time, since the modified valve could let water enter through the breather line if the valve is submerged.
The grease in the knuckle is effective in keeping water out and if it gets in, I think the water will be forced out of the wiper seals.
Hey,
when extending the lines what type of valve are you using?
I have read the threads on extending them but haven't seen anything on what the best valve for the end of the line is?
I modified the stock rear valve to remove the flapper. Since the rear breather was extended and T'd with the front breather, only 1 valve was needed. Others have used a generic fuel filter or a lawn mower fuel filter.
I'd also push for a check vs. a 'you must change' approach. Where I wheel, we spend a fair amount of time doing deep water crossings (deeper than 2'). When I've checked, my diff oil has been fine. That being said, I generally change my diff fluid 1X per year and I have the extended breathers.
An even better plan is to take out that crappy Toyota 1 way valve and throw it in the bushes. No sense modifying it. A generic fuel filter with the appropriate inlet size works great (and better than a modified flapper valve) and will last the life of the vehicle.
Concerning the original question, I don't see the sense of checking the diff oil for water contamination. By the time you are able to check it, you have done 99% of the work of changing it. If you are worried enough to check, which I would be given the description, just change out the gear oil and be happy. Then you can forget about it, and the gears will enjoy the fresh oil.
