or more importantly, keep your fluids cool! - ATF - Power Steering - engine oil - diff oils - coolant 4x4's get worked hard.......even in -35 C temps. Summer temps are even worse.....long drives in low range up miles of steep grade mountain roads, all wreak havoc on your cooling system, engine oils, tranny fluids, power steering fluids and diff fluids. Add payload and towing and this pushes the boundaries even more. Often to failure , expensive tow bills, wrecked vacations, and expensive repair bills. when these fluids (excluding coolant for now - will go into that below) are constantly overheated, they break down rapidly and oxidize, and start building varnish on critical passages , esp in today's micron tolerance auto trannys. This leads to poor operation, sticky valves and more heat build up,and ultimately transmission and transfer case failure. vehicles from the factory, EVEN rugged 4x4's, are ONLY equiped with the "bare" minimum in the way of tranny and engine oil coolers and fans. Just enough to get the job done. (but poorly). 98% of people never touch their fluids, (changing them, upgrading to synthetics etc). You see this when you pull the dip stick and smell burnt tranny fluid, or pull the oil cap and see sticky sludge everywhere, or pull the cap on the powersteering system and it reeks of burnt and degraded fluids. Over the years of driving, there is one thing i always do on my rigs: - full swap to hi end synthetic fluids (engine oil, ATF, transfer case (often uses ATF), power steering fluid and diff oils). I run Redline Hi Temp ATF in the transfer case and auto trans , Redline 5W40 synthetic oil in the engine, Redline synthetic powersteering fluid and Redline 75-140 GL synthetic gear oil in the diffs. (your vehicle requirements may vary) Synthetic Oils cost more, yes. But the protection it gives your components extends their life by hundreds of thousands of klicks. In the case of engine oil, its a $100 oil change...HOWEVER....changing the filter every 7000KM's and topping it up, and using OIL ANALYSIS, I extend the drain interval. I recently passed the 100,000KM mark on my drain interval, and oil analysis reports indicate that oil good for another 25,000+. I use 1 micron Donaldson oil filters, swapped every 7000 KM and topped up 1/4 quart of new oil. My oil is CLEAR, like honey. So while the initial synthetic oil fill is expensive, over the long run , using oil analysis and high end Donaldson filters, its actually cheaper. My 250,000 KM engine tear down looked like a NEW engine, not a single deposit anywhere in the engine. The mazda engine has 365900 KM's on it , zero deposits, clean engine, no wear, and still has factory compression (28 year old engine) same with the auto tranny. I have a remote spin on Donaldson filter (coupled with the factory filters, this gives me 3 stage 10 micron, then 5 micron, then finally 1 micron filtration) . Again, oil analysis is used. I also install massive aftermarket plate and tube coolers, for the tranny and power steering cooling. These are BYPASS units, the fluids do not flow thru the main part of the cooler until a certain temp is reached. On the tracker, (2 liter engine) i have a Dana Corporation 30,000LB GVW plate and tube cooler (from a massive diesel tour bus). I have yet to go over 165 degrees in summer mountain driving up steep grades. Meanwhile my friends are pushing 220+ degs and burning their fluid and friction band material out. (most of them have upgraded now) I can maintain very low temps, even in 40 deg C Lytton temps, crawling up logging roads for hours at a time. Coupled with the synthetic fluids, this extends the life of the components. I also open up the hood with a vent grille, and let the heat rise out naturally, this also protects other components under the hood from excessive engine bay heat, and helps the engine shed more heat. onto the engine and diffs......aftermarket oil pans with cooling fins and added capacity are available, same with diff covers. This is called passive cooling. More oil is good. the cooling system in 95% of 4x4's is taxed to its limits daily, esp with air conditioning and cramped engine bays, just in daily driving . The solution is aftermarket electric fans, both pusher and puller fans. These move MUCH more air thru the radiator than the factory electric fans or mechanical fans. As well, you can add a switched timer to cool the truck down after you shut it off, to prevent sudden heat soak on the top end of the engine. Shut the truck down, turn in the timer and the fan will cool the engine and engine bay down for 10 15 or twenty minutes. A lot of people do not change their coolant enough. Some don;t change it for years. It builds up acids and loses it additives over time. I change mine twice a year, in the fall when i winterize the truck, in the spring before summer. Coolant is so cheap it not worth leaving in for years. Frequent changing will eliminate crud and deposits in your cooling system, this will prolong the life of the cabin heater and the rad. In turn your engines cooling system will work at peak efficiency, this will also prolong the life of your air conditioning system. food for thought. (note i do not work for nor am i sponsored by RedLine Oil. I pay for their products out of my own pocket. )
@Bushman5 -- Great information. If you take nothing else away from these comments take this -- HEAT KILLS. If you aren't up to such a rigorous maintenance schedule and the testing that Bushman advises then at least consider more frequent changes of fluids on the common ignorables; coolant/antifreeze, tranny fluid, and diff fluids.
