My Chilton manual says to inspect, service, and lubricate my idler arm on my 2000 Ford F-150 4x4 every 5,000 miles (as this is the only thing that isn't permanently lubricated during manufacture). So really, around how often should I lube it (i.e. how much does "inspecting" tell me), if I'm not driving through deep mud/water and off-roading all the time?

Also, it says verbatim re/ Drive axles, "Drain and refill the front and rear axle housing every 24,000 miles, or anytime the vehicle is operated in deep water." I buy the deep water part, but do any of you change your axle fluid every 24,000 miles?

Heck, I know some people who don't change their oil that often...I was thinking of 100,000 miles + for the axles....
This isn't a typo in Chilton is it? If so, I'm lucky I'm not sophisticated enough to really get involved in retooling something. I'd hate to read that I should only touch the striped wire from the secondary coil, only to find out that there was a typo and zapppo...

 

Sorry, can't really help with the idler arm, if in doubt, lube it. Call me the fool, but I do change my rear diff, T-case and tranny fluids around that many miles or just a few more. The front I will usually only do every other time, due to having a part-time 'case(and having to remove the cover to do it!). The main reason I do this is concern over condensation more than contaminates or fluid break down. Every time it's taken out on longer runs, that heats up the fluid and it expands a little, when it cools back down it draws outside air in to take up that space and along with that, any moisture that's in the air. In my opinion, I have to much invested to take a chance on something as relativly cheap as a fluid change, even if it doesn't really need it. Of course I'm only pushing 300,000 miles and just over 10,000 hrs. but do expect to double that easily with proper care and feeding!

'79 F-150 (badged as a Crown Vic) SWB Flairside 4x4 468 ci ThunderJet C-6 NP205 TruTracs front and rear

 

As I should have done first, I checked my service manual, and Ford actual only has front and real axle lubricant replacement at 150,000. But then apparently contradicting itself a page or two later, it says "Rear axles containing synthetic lubricant and light duty trucks equipped with Ford-design axles are lubricated for life. These lubricants are not to be checked or changed unless a leak is suspected, service is required, or the axle assembly has been submerged in water." I assume that would apply to the front axle, but maybe not.

Very weird. I've got Chilton saying change axle lubrication at 24,000, then a few pages later it says 100,000. Then in the Ford Service Manual for 2000 Trucks, it says 150,000, then a few pages later it says never....

Oh well...

 

Yeah, should have asked if you had the synth lube and sealed axles seein' how it's basically a brand new truck. That's what I have been told, the newer ones are sealed for "life", unless there is a problem or water contamination. I don't think yours uses a breather for the diffs, but rather has a bladder of some sort which would allow for the expansion and contraction of the fluids, making it a sealed system. Might want to check around on the rear for a hose that would run up to the frame but doesn't go to anything as such. If it would have one, then this would be the breather. If it doesn't have one, and I don't think it will, the only thing to be careful of is quick submersion when hot into cold water, when it is over the axles and above the pinion, this could cause the seals to allow a little water past them. I did look on the work van, a '01 E-350 SD and that has the breather on the standard location, the brake line "T". The reason that there has to be some place for expansion is that if there is not, the seals would have to hold pressure, very slight at that, but a pressure none the less. The seals are not made to hold this and will weep, I know this from first hand experience with a blocked breather, weeped out the pinion and axle seals! The Chilton/Haynes type manuals are kinda a catch-all unless it's specific for your year and model, plus they have been known to have some conflicting/incorrect info as compared to what the factory calls for, take it with a grain of salt? as they say. Have a good one, hope your enjoyin' your ride!

 

2000 trucks have a extended life synthetic 75w140 gear oil in the rear and sometimes the front differentials.