Unlocking the Truth Behind Automatic Lockers

Here is the deal. Whenever there seems to be growth in a segment of the aftermarket world whether it is the street world, off road world, even the race world, not long after a product reaches the end users the rumors start. Some of these rumors are based on truth, some are based on end user error, some of them are based in hypothetic knowledge vs. direct knowledge, most rumors are based in the never ending side talk focused on “us vs. them” with no practical knowledge to begin with.  The debate about Automatic Lockers is nothing new, since almost the inception of the Locker, the conversation for and against the Locker has been had around many a campfire, barstool or garage talk. This article is going to move some of that conversation out of the myths and into the facts and personal experience.

Anatomy of a Detroit Locker

Anatomy of a Detroit Locker

FACT: An Automatic Locking differential is a differential where the coupler gears of the left and right axle shafts are locked together in unison as power is applied to the axle through the pinion gear. The “Locking” Mechanism is normally a center section of the differential, most commonly called driver gears or a driver assembly that are placed under spring tension. The Pressure from springs forces these driver gears into the side coupler gears making the whole axle turn together at the same speed.

Pros of an Automatic Locker- Because a locked axle turns together in unison and there is no slip between the left or right tire, the tires are actually receiving 100% of the power being sent to the axle. Other traction devices such as Posi-Traction or Limited-Slip Designs at most can transfer only 65%-70% of the power given to them to the ground. If you have ever had the chance to experience the difference, it is absurd. A locking diff vs. a Limited slip diff is more than noticeable, it can make a driver laugh hysterically while stating terms of invincibility as they idle over previously challenging obstacles. 

Most commonly in some gear driven limited slips, the differential has to allow one tire to slip, causing a ratcheting effect in the differential which transfers power to the other side. This slippage equates to loss of power and to loss of momentum as the differential transfers power. With Posi-Traction differentials which instead of gears inside have clutches, this differentials has no “ratcheting effect”, instead power is transferred between each wheel through the use of a clutch pack. The inherent problem with clutches is that “slippage” between axles equates again, to a loss in power. This is why in this aspect a locker has zero mechanic slip and therefore transfers 100% of the power it is given.

These mechanical traits are only highlighted further with a locker when you start driving a vehicle with one. When driving a vehicle with a locker you start to notice certain things that are no longer happening when off road, like the fact you do not hear tires slip, you also will notice that you will not feel one tire break free and then transfer power to the other. With each tire turning together at the same RPM’s or Revolution Per Minute. There is noticeably less abuse on the whole drive train with a locker.

Cons of an Automatic Locker- Because the unit is “automatic” the driver cannot dictate how and the when the unit LOCKS or UNLOCKS. While there have been some wild accusations and urban legends of people flying off rainy roads, sliding through ice, and “lockers making vehicles wildly undrivable in poor conditions.” I would like to take time and ask….then why would anyone want them if they make a vehicle so uncontrollable to drive?  This is when the “no personal experience” keyboard warriors seem to come out in droves… I have driven an automatic locker in every terrain imaginable, fresh rain, down pours, sleet, snow, mud, sand, rock. About the biggest down fall of an automatic locker is they can chirp tires on pavement when making tight turns, they can make clunking or clicking noises making tight turns in parking lots and they can make a vehicle want to oversteer (Drift)  if you apply too much power in a low traction situation. The most common side effect of a locker is at times the differential will unlock and lock around a corner which can feel like a jostle in the cab.  Most common con thrown out on the forums aside from DEATH with an automatic locker is that with lots of street use an Automatic Locker will also cause your rear tires to wear “more” than without a locker (from the chirping, scrubbing of the slower moving tire through a turn.) There has been no research to my knowledge to prove just how much “more” tire wear that is. I am trying to document this through my daily driven RAM 2500, and so far…my tires are not melting away as suggested by the keyboard keepers of the off road realm. But more on this later.

Why would you want an Auto-locker?

Cold hard facts? First, an Auto-Locker is dirt cheap next to comparable selectable lockers like ARB, OX, Eaton E-Locker, etc. Just in hard parts for a Dana 80 rear end. An Automatic Locker can be had for about 700 dollars (lunch box lockers can be had for sub-$400’s) Where for the same unit from ARB, OX etc. with the needed compressor, Cables, levers, can quickly add up to 1500 dollars+. Thats firgure is just parts, we havent even talked about install. 2nd reason, the Auto-Locker design has been around since WWII,  95% of the Locker’s available today are damn near bomb proof. While almost every off road forum will tell you that its Toyota E-Lockers or ARB air lockers till the messiah returns, the fact is…You will never need an electrical relay or an air solenoid in the middle of the desert with an auto locker. With no need for any supporting modifications (air system, electrical wiring) an auto-locker always works. I own 2 rigs with lockers, one being my Jeep YJ with ARB’s front and rear and the other is my Trail Pig, a 99 Dodge Cummins 4x4 with a Lock Right in the rear. Only one has led me to modify an off road trip because a locker was not functioning properly. Hint: It was not the Lock Right. Double Hint: I love my ARB’s and would not change them for anything in my jeep. Wisdom to be learned? All things have a purpose when we understand INTENT. Back to the Automatic locker, the next point is maintenance.  Automatic Locker’s are like crockpot’s, set them and forget them. Air and Electronic selectable lockers have wires that can chafe, airlines that can crack, O-rings that can go bad in the units. Do not read that automatic Locker’s are infallible, but I have talked to a lot of Detroit and Yukon Grizzly owners and short of trying to be King of the Hammers, or throw 600 hp onto a rock face, automatic lockers have a very low fail rate in the wild. Normally what kills a locker is something else breaking and taking out the side gears in the locker.

So let’s sum this up again, Reason why an Auto locker would be appealing? Lower Cost of ownership than other Traction Devices (Electronic, Air, even some Limited Slip Diffs.) NO need for supporting mods (air tanks, compressors, electronic wiring.) Low Maintenance (No special oil additives, no clutch fibers to replace.)


Myth #1- Locker’s make your vehicle un-drivable on the street.

False*-  I use an asterisks because in the world of the interwebs, half truths become whole lies and the Forums (the meeting hubs of the largely uninformed) are divine instruction. I also want to walk through some of the exaggerations mentioned on the internet. This myth is one of the previously mentioned half truths perpetuated by many individuals with no direct knowledge or experience with a locker at all.

An automatic locker will not make your vehicle un-drivable for “daily driving” duties. I have one in my truck, I drive 400 miles a week in Orange County and LA. I park on narrow streets, I make U-Turns by the hour. I haven’t wanted to throw it all in the trash yet. Not once has the Locker tried to kill me (this has been disappointing.) People say an Automatic Locker behind a manual transmission will make your vehicle “change lanes” between shifts. WRONG, People say you will be followed constantly by, clanks and bangs and your vehicle jumping and jostling at every turn. Not ALWAYS true. Once you drive with a locker you learn how to drive WITH  a locker. Like any modification to a vehicle, you learn how to drive a vehicle differently. You have to adjust your driving when your vehicle is lifted from stock, why is it so much different when you upgrade something like your differential? Once you have a few days in your vehicle You learn how to add and remove power to get the differential to unlock. The only time the diff makes noise for me is when I am making U-turns or sharp turns in parking lots.  Another example is when making right and left turns from stoplights normally the only sound I hear is a tire chirp over a paint strip. Never have I felt the locker make my rig unsafe. 90% of the time I have no idea the locker is there. For those warming up the war drums, I have driven my own vehicle a ¾ ton Dodge Cummins and a Jeep XJ with Lock-Rights in the rear axles, both sticks, and both over at least 1000 miles. My experiences were the same. Yes a Locker in a heavier vehicle feels smoother because of the weight of that vehicle leveraging against the differential, but I never experienced the exaggerated symptoms I have heard about on the interwebs.

Myth #2- An automatic Locker causes increased tire wear

Half-Truth-  The logic behind this comes from the fact that since both rear tires are locked together one wheel has to “scrub, or chirp” to catch up to the faster moving tire. The logic is correct. This goes back to the “learning how to drive with a locker.” If I power through a turn, the differential locks up and I get the chirp. If I allow myself to cost through a corner, the differential unlocks and I do not chirp a tire, then no additional tire wear happens. However, once you have a locker installed…it seems some side effects of “hoonage” happens, which means….for a short while, most people like chirping tires around turns or the fact that your peg leg vehicle is now a drift ready metal missile. So sorta like the MPG message… your miles may vary just as much as how many drifts you would like to do….


Myth #3- An Automatic Locker in Snow Equals Automatic Death.

FALSE*- Almost always the first post after a, “Should I get a locker?” post is the race to be the first person to state that in the snow, “Your truck is going to immediately slide out of control.” So let’s take this one slowly. If you are the type of driver that would have killed yourself by now in life without traction control on every vehicle you have ever owned. I don’t have an answer for you. Stick to micro coffee brews and farmers markets. But I am going to assume that people CAN LEARN and can get progressively better at something. A vehicle with a locker in it on ice does require more focus to drive than one without, but interestingly enough, both vehicles are hard to drive, and if you are not focused on your driving in either vehicle, most likely your chances of a favorable ending to your adventure are not good. Driving a vehicle without any traction control or traction devices in the differential makes a vehicle constantly pull to whatever tire loses traction, where a vehicle with a locker will oversteer more in similar situations, normally pulling towards the direction of gravity. Oversteer is when the rear end of the vehicle wants to “physically pass” the front of the vehicle. Think drifting. Many people seem to forget that if you feel the rear end start to “step out “ or start to put the vehicle into a slide…. YOU CAN LET OFF THE GAS. Which will normally make the vehicle get back into line and solve that whole situation of an icy death. (again, certain off camber situations can get more interesting as again a locked vehicle will want to slide toward the direction of gravity.) But, NO, a locker will not make your vehicle un-drivable or unsafe in the snow.

 Even in my Wrangler which I have used for years as my go to snow machine, I have always left my ARB locked in my rear axle in some of the deepest snow situations I have ever been in and my vehicle has never acted out in a manner that made me unsafe. Even now with the Ram, I had the opportunity to drive on a very icy HWY 18 in Big Bear. The biggest thing I can recommend is driving at safe speeds and driving corners with the respect they deserve. I had 2 times in a 2 hour drive where the truck stepped out on me, both times all it took was rolling off the gas and rolling back on smoother.  For years ACROSS America, lockers have been used in snow plow rigs….if the MYTH of icy death was true….how the heck did Detroit sell so many for so long?

So in closing, I want to make one point 100% clear, YES, a Locker will make your vehicle feel different in certain situations. An Automatic Locker will be more noticeable during daily life than a selectable unit such as ARB, OX, Eaton, etc. With an automatic locker you will not want to take corners as fast in the rain, or ice, but you shouldn’t be Ricky racer in those situations anyways. Do I think that automatic lockers are for everyone? NO, if you are a super picky person, if you want your truck to drive like a Lexus, then an Automatic Locker is probably not for you. But if you are okay with wearing your jeans 2 days in a row and are 100% for instating the death penalty for Man buns, an automatic locker might be the right choice for you.

That’s my .02 cents


Purchasing an Overland Rig

With the growth of the phenomenon that is "Overlanding" comes some grey areas of the sport. While most of us spend our free days out on the trail enjoying every bit of what "overlanding" means to us, I also recognize a new segment of the population that is popping up. Most of us have been doing this before "overlanding" was coined but for the new segment drawn in by social media and trail rumors I have recognized some people are getting straight hosed. I mean this in a completely professional manner as well. For the past 11 years I have been either a fabricator, mechanic or salesmen for off road performance accessories by trade and as the landscape has changed so have the customers I have come to service. It was actually these very same customers who lead me to this site and community.  So as a daily mechanic/ service writer let me share with you the tips and tricks of buying a good rig or more importantly the right rig. 

Place of Purchase-New
Here you are pretty much forced to go to a dealer but first lets talk about the up-sales. See we all love the TRD pro's or maybe that trail hawk package has you stunned on the new Grand Cherokees. Whatever your poison is the dealer is always willing to add salt for taste. But what I am more concerned about is the fact that most of the people that show up looking to upgrade their rig after the purchase high wears off go straight for the extra "package" stuff they paid top dollar for and they throw it out. Now arguably what you will find is some things like locking diffs sometimes only come with the TRD packages, or the heavy duty, locking axles (rubicon/Powerwagon) only come with some of their packages, but do you your research, find the package you want, and make sure you are willing to dish out the extra 2500+8k plus for an option that results in pretty much stickers, shocks you are going to ditch in a year and rims you will have sold on craigslist. Or the “rock Sliders” that end up selling anyways cause there are these other ones that are thicker and have a step…..New is wonderful, new is nice, but do not be the guy sitting at a trail head in your shiny rig wondering if maybe you should have spent money on different aspects. Here is also my tip of the day, having worked with dealers in limited capacity for past SEMA work, find what you want on their website and then call for their online fleet manager. They will try their hardest to keep you away from this guy, but he or she is the candy man uh...woman. They are able to order at your request, check other dealer stocks and more importantly, they are a strictly numbers people. They want to have a car count in and car count out. You do not need to purchase 25 cars, they are more than willing to help anyone on the phone. My recommendation is have your vehicle picked out, the packages you want and if you can have the build sheet in hand while on the phone. The fleet managers have always gotten it done for me and at prices that didnt make me sit in an office for an hour while my salesman DIDNT ask his boss for a better deal. EXAMPLE: Recently I had a customer who wanted a Rock Warrior Tundra, he was licking his lips and wanting one so bad, but the price was just freaking too much to bear. He spent 2 days calling around to Fleet Managers and found a Limited Tundra, crew cab, configuration he wanted 4x4 of course, and was able to have the dealer swap alloy rims for steel wheels and get one with a LSD rear diff. At the end of the day he was 5 figures cheaper and spent roughly half that on building something that was his own. with the rims, tires and suspension he wanted. 

Place of Purchase- USED
So the vehicle is a few years old, or 20... give or take. Here is my recommendation as a mechanic, do not buy a used car from a dealer and do not care about what CARFAUX.. I mean CARFAX has to say. Now let me dial it back, I understand some of us need the financing and the dealer is the only game in town. But understand this, most used cars come from an auction, they were sent to an auction because some dealer took it in on a trade and then didn’t see the advantage of keeping it, it may need work, it may have needed work, for some reason it was deemed a liability. You also have no history on the vehicle that is tangible. It could have been lovingly cared for by a grandfather, or it could have been a 16 year old BJ Baldwin Wannabee. Just be aware of the limitations but that does not mean you are incapable of finding a sound rig. So back at the dealer, then my recommendation is when you find the vehicle you want you need to immediately ask the dealer for an inspection pass for the vehicle. Some dealers say take it for 24 hrs, others say 4 hours. But what you want to do is take a list of their "100/200 point Certified Pre-Owned (CPO)" check list and take it directly to a mechanic you trust. Why you are doing this is because dealers are not always honest and a check-list largely made up of menial stuff that does not matter to the health of the vehicle will not actually give you the clear bill of health EXAMPLE: Not an overland vehicle, but the shop I work at had a great customer come in with a CPO  2015 Mini Cooper, clean little car, clean carfax, super low miles and the thing was half the price of a new one... WOW, even I loved it... 2 seconds with my scan tool and boom, 42 codes, 12  stored engine codes, 7  pending brake codes, 23 body codes. Ended up finding the vehicle had been in 2 accidents that were not reported (body panels/ bumpers did not have manufacture body codes/vin). She was buying someone else's lemon.
The reason you want the pre purchase inspection is also an honest answer on how the vehicle is maintained. Many times the fluids will all be fresh (cheapest thing for a dealer to fix). But how about brake percentages? How about past repairs? Generally an independent shop can tell you when things have been replaced. Maybe valve cover gaskets dont match or there is silicone on something that shouldn’t have silicone. Most independents with a smog machine may be able to check previous tests? Has it had a history of failing smog? why did it fail smog? In fact you can check any car in CA by simply typing Vehicle Smog Test History in google and checking the first dmv link. (I would link but I was told it would block my post.) It is crucial to make sure your vehicle does not fail based on improperly installed cats, incorrect sensors, the list goes on. But again a good honest independent will help you steer clear. 

The next thing is having a truck up on a rack tells you things, a mechanic will be able to find bends and twists in things that shouldn’t be there, maybe you have accessory covers that are missing. Rocks make noises and leave kisses, its a sign of their affection. Maybe the tires are wearing funny, is this because of tie rods, ball joints? Bent arms? Improperly install lifts? Or just a bad alignment? How about diff fluid? These are hard to check at a dealer, but up on a rack much easier. Remember shiny objects whether they are in jewelry or engine/gear oil both mean the same thing. MONEY. Again, an honesty mechanic will be able to tell you if they feel anything is in danger or not. Now remember you can take your independent advice back to the dealer and some dealers will not care at all, their price is take it or leave it. But I have always experienced some dealers who are willing to go out of their way to make their customer feel satisfied. I had one Toyota dealer do a timing belt, waterpump and cam seals because the vehicle was right at the scheduled mileage and they didnt charge the customer, I had a dodge dealer replace front and rear brakes on a Ram3500 4x4 because what the rotors were undersized but the pads where "above 60%". Again, free because it was brought to their attention.

O no.....the dreaded upsale AGAIN. It is a used car so what they are going to hit you with either  a manufacture or aftermarket extended auto warranty. What you need to know is that the dealers make more off of the aftermarket warranties than the manufacture warranties. So they will most likely push an aftermarket, this is however, what you need to know regardless. Read every page of the warranty they put in front of you, check to see what it covers.  Skip to the "stated not covered repairs" what does it read? Does it replace ignition system components? emissions equipment? Head gaskets? Transmission failure? automatic shift solenoids? Again, your trust independent mechanic will most likely be able to tell you what the automobilese you are reading actually covers. But it is not all bad. Toyota, Ford, Chevy, Dodge and Jeep seem to have pretty good extended warranties, I have had transfer cases replaced, mode doors and actuators taken care of, but again there is a lot of mumbo jumbo out there where you end up paying 3800 dollars for an extended warranty that will replace a sun visor bulb but not an exhaust manifold.  The only two aftermarket extended warranties I have had any luck with have been Endurance and Carchex.  Both have replaced transmissions, suspension components and drive axles. Both require a deductable which was either 250 or 500 (check your warranty I am sure its related to level of coverage) but the nice thing was they paid us directly and the customer just walked in, gave us whatever the deductable was and off they went. (I am not a lawyer, double check yourself, I have no affiliation with them).

Craiglist Abyss

A lot of people give CL a bad rap, ooo its a bunch of bottom feeders, a bunch of con artists, a bunch of dishonest shysters. I am sorry... have you seen our politicians (composes self). What I am trying to say is for every Nigerian Prince with a 7 figure banking problem there is still 10 or so (statistic made up on site) good people selling good cars with good intentions. Again, Call them up, go look at the rig, ask them hey will you take a deposit? Can we go to a mechanic tomorrow for a pre purchase inspection? Most will happily oblige. I have always said, "hey let me pay 105 bucks(standard rate for an hour) and get a pre purchase inspection and if I decide to pass you can at least have the bill of health on your car for the next guy".  Most of the time again no problem. If the seller is really apprehensive of such a request, I personally would back away from the sale. People should understand whether its 5 grand or 50 grand it's a risk. However, maybe this is still not possible to here is your checklist

Coolant- there should be no "floaters" that is a professional term. Floaters will normally look like white scale or small little floating crystals, these show up when coolant has not been maintained.  Number one "AH HA Caught you moments" is normally when the radiator is full of fluid and the recovery bottle is empty. There is a leak somewhere, do not let someone tell you different. It is low for a reason. Most coolant drain and fills are about $150 bucks parts and labor. Also if there is any fluid floating on top of the coolant it can be multiple things, I have had teenagers put brake fluid in radiators because they did not know better, and I have also seen oil in coolant from head gasket failures. There should only be one fluid in a radiator (it’s radiator fluid)
Coolant Colors
Toyota- pre-03 red, post 03 pink (this is a blanket standard some got different colors sooner later) if it is green or orange it is wrong
Chevy/Dodge- Should be orange, each manufacture has their own name for it but it should be orange from 96-up.  The diesel's is where it gets complicated, it should technically be orange, but as long as the fluid is something like a fleet guard extended life diesel coolant it should be fine. 
Fords- pretty much 98 and up it should be Motorcraft Gold/yellow color, again diesels can go either way from the factory they should be gold/yellow, but you can run old fashion green in them with the proper additive, or the fleet style diesel coolants. 

Reason I list colors is because if you get any browns or purples you may be looking at a contaminated system which will require a flush and a new thermostat. Depending on the vehicle that can be a 250-500 dollar expense right out of the pocket book. Blending coolants can lead to scaling and corrosion in the cooling system, this eats water pumps, head gaskets and jumpstarts electrolysis. 

99% of the time this fluid should be bright red, fluid that is starting to turn will go from bright Red to roseish red, to orange, and then brown/black. YOU DO NOT WANT IT TO GET PAST ORANGE. What does this mean for your transmission... This is a crap shoot. I have customers that flush their transmissions every 30,000 miles and their fluid is dark dark brown each time and they have over 200k miles and still ticking. I have people who have never had dirty fluid in any of our inspections and have lost transmissions before 100k.  What we are really looking for is the law of averages here. 
1%- Allison Transmissions and pretty much anything european actually have clear looking transmission fluid.  BUT this also has changed a little the "Transynd " Allison specific fluid has changed in later years, the new bottles have more of a tint of red then the old stuff, so if you pull a dipstick and its nice and clean and clear. it may just be the original fluid, if it is red, ask the owner if they used Transynd, if they know nothing about it, keep this in mind. There are now "aftermarket" fluids that will work in the allisons but for the longest time and pretty much the industry standard, it is best to have the Allison fluid in them. 

Engine oil- Gas rigs, check the oil, is it low? Is it black? If you rub the dipstick on the back of your hand and cannot see your pores/your own skin color underneath, its too dark, is it black and low? This might be a sign of poor maintenance records or an engine that is not running properly. Is it low because it leaks? Is it low because it burns oil? Dark and low on oil can pretty much sum up stuck piston rings or bad valve stem seals. The more often the vehicle has had shotty oil changes the more aware you need to be about the possible need for future additives to try and loosen up stuck rings such as Rislone Stop Smoke Ring Repair additive, B&G, or Engine Restore. I have always had best luck with Rislone or with motors that have been abused I will run a quart of ATF (it is a detergent) with my next 3 oil changes. normally the ATF will help clean the inside of the motor and help get the gunk out.

Diesels- Diesels need pretty much 4 things there whole life, air, heat, fuel and oil. Since these engines have higher compression, deal with higher heat and pull heavier loads oil is very very important. Many of these systems are 14 quarts or more and they run a lot of things. The newer diesels depend on oil to help with their variable geometry turbos (VGT), the oil itself on motors like powerstrokes actually help fire the injectors and so when oil is neglected and allowed to run low this means maybe the turbo has excessive wear from being run low. Powerstrokes are famous for stiction, which basically means the oil passages in the motors, high pressure oil pumps and injectors get clogged. Different solenoids can become clogged. In general, oil is very very important and due to the fact that replacing an engine in pretty much any diesel is a 15,000 dollar PLUS date. Make sure it is taken care of. Now with Diesels the old “dark oil” test is a no go. I can put fresh oil in any diesel motor and fire it up once for 5 minutes and then pour out dark oil as soon as I shut it off. Just make sure the oil is on the stick. If the oil level is a little below full that’s okay. If the oil is not reading on the stick. That is not okay. Again, Law of averages.

Brake Fluid- perfect color is almost clear/gold. Most..... its either charcoal colored or black. Charcoal suggests an average maintained system, pitch black means there is contaminants, most likely water, rust and fine metal particles. So what does this mean? Most of the time a simple flush will straighten everything out (does the pedal feel soft? old fluid will make it feel squishy and the pedal will go down further). Another observation is that sometimes on vehicles with drums in the rear, improperly adjusted rear brakes will also make the pedal go down farther and make the vehicle feel like it does not want to stop. Keep this in mind as well.  But dirty fluid is dirty fluid. Next is the level of the fluid, is it low? is it empty? if It is low most likely it is a sign that either the front or rear brakes are needing to be done, but as the caliper and wheel cylinder push farther out the amount of fluid in the reservoir becomes less. If it is VERY VERY low, then you may have a situation where you have a leak somewhere, it can be a leaking caliper or wheel cylinder. But a system that is maintained should not be low or dirty.  #law of averages.

Okay Overland Therapy I have a rig in front of me, oil is dirty and low, brake fluid is dirty and low, transmission fluid is brown and coolant bottle is empty and the radiator is full. What do I have?

You sir/fair lady have a story, most likely the vehicle may run fine. It may not show any signs of abuse, but you have a solid case against the law of averages. In all reality it sounds like the average car I see everyday, but that does not make it great. It means the seller most likely does not routinely check his or her fluids, needed repairs may have been declined and you should just be aware that fluid does not disappear. If the coolant bottle is empty and there are no immediate signs of leaks, it might be the water pump, they can leak right after being started and then seal up before you park it at work 10 minutes later. an water pump on say a UZJ100 Landcruiser is most of the time completed with the timing belt, crank seal, cam seals and idler pulleys. That can instantly be a 950-1100 dollar repair. 

Thats why I stress the importance of having your potential rig checked out, are the brakes wearing evenly? Do you know? a pre purchase inspection will tell you, is this caused by a caliper issue or maybe drum brakes out of adjustment? the list can go on and on.

Aftermarket Parts
This is one of those segments that is a double edge sword. It is so nice to find a FJ80 with an ARB front bumper and winch already installed, its like 3k just hanging there for free. But while a winch bumper and winch may be an awesome addition there are other things to be concerned about. A lot of people out there finance their rigs, then hit up amex for zero percent and then make a catalog throw up on their car. If you have seen pretty much 80% of every JK Wrangler on the road you have seen it. It's like Helen Keller grabbed a 4 wheel parts catalog and a dart board. Again what are you paying for? OOO it has 18 inch rims, thats so sick.....but it also limits tire availability and they actually suck off road. 17 inch is as big as you need for 99 percent of the rigs. Unless you are hanging a 42 inch tire off of your rig, do not even think about 20 inch rims. You will not get traction and "airing down" is actually more of a "lets blow a bead in the wild" proposition. OOO it has a 6.5 inch lift, perfect!! How much fun is it going to be loading and unloading it...and are you going to put a RTT on it?  Ever seen a skinny chick with big hair in the wind? Now experience it on four wheels.  Now granted this wont be the experience with every rig. But take the time to think it out, why did someone spend 20+ grand on something in extras to burn the cash and get rid of it? I always laugh when I see the ad for this absolutely sick looking vehicle and then it says "will only trade for stock truck plus cash". A lot of the time the "postcard rig" does not end up being the capable cruiser they set out for. 

Suspension- I was in this industry and the companies backing these products come and go like the wind. LIFETIME GAURANTEE….but our website is gone and our phone is disconnected. Make sure you buy a vehicle that if the suspension has been modified it has been done by someone you can still get parts from, or from someone you may not need to get parts from.  Old Man Emu is a legend, Rubicon Express, Carli Suspension, Kore, Fox Shox, King, Total Chaos, Cognito, CST, BDS, Slee Off road. These are all companies I have worked with, and sure there are other names, but look into and do some solid searching on does their lift fit an aesthetic need or a functional need? I have seen too many lifts destroy ball joints, tie rods, cv-axles and steering components because they were engineered for looks and not function.  I have one truck I cannot for the life of me get to track true without burning up tires because the lift kit was engineered so that I will never be able to get proper camber adjustment on one side. Worse thing you can do is actually go backwards from what the factory had.  Dont end up buying someone else's mistake

Lockers and Traction Devices- I MUST MUST MUST insist that if you are buying a rig and they claim it has a traction device that when you do a pre purchase inspection you simply ask if they are willing for you to pay for a diff service or ask if your mechanic can take a peak with a bore scope. $100 bucks can save you on a $1000 dollar lie. I had a customer come in a few months ago and show off his newly acquired BA rig and it was, it was a solid rig built well. "It has lockers front and rear". Drive around a corner..no locker-esk symptoms. Put it in 4wd, steering did not get stiff.... My heart kind of sank and I decided I would check it for him during his now "after purchase inspection". Luckily I was able to use a bore scope and found his front and rear diffs where OPEN....not even LSD in the rear. He had admitted to spending close to 2k more than the closest comparable Rig based on the previous owner's statements.  He had no way of tracking the scammer down. For things like "its got Detroit’s, or Arb's, Yukon grizzly, LSD or the list goes on and on" Have a mechanic check it out and ask for receipts!

Well thanks to all of you that stuck it through to the end. I hope this helps you going forward!! Good luck on the adventure!