Some basic troubleshooting concepts

I see it all the time on FaceBook and other forums for mechanical advice: people, usually dudes, that cannot think straight. Troubleshooting is logical experimentation, like science, only generally a little faster and looser, so the job gets done in a reasonable amount of time. If you can't think straight for one reason or another, you can't troubleshoot. Reasons for not thinking straight vary, but they are usually to do with making assumptions that just are not correct. 

I have to admit, there's also a lot of ignorance and plain stupidity. But technique is not going to help the latter, and most ignorant people don't know what they don't know, so you can't help that either.

So lets make a list of some techniques to avoid making incorrect assumptions while troubleshooting mechanical repairs.

First, up, read the manual. There are times when you can't get one, that's for sure, with older machines or custom and homebuilt ones that never had a manual in the first place. But 99% of the time there is a manual, and you can generally find it for free online. 

Use Google. Search by the name of manufacturer, the model number, or name and year and any other identifier. For example, my home emergency generator is a "Generac Guardian 0043892 7kW manual". Always add the terms "manual" and ".pdf" after the identifiers. That tends to throw the actual manuals further up the search results and weeds out all the commercial sites. These sites will sell you a manual. But if you look hard enough, some kind person will have scanned it and uploaded it somewhere.

Here's the generator search results: Generac Guardian 0043892 7kW .pdf

You can see that the first page is the manufacturer's support page, with links to the correct manuals.

Now let's try my boat motor, a 1979 Mercruiser 120. The first several listings turn out to be commercial sites, or the more popular newer Mercruiser engines.

But bingo! Half way down the second page of results we find https://web.statler.wvu.edu/~mathews/boat/pdf/manual/Chapter%20Six.PDF

I rarely strike out finding the right manual.

Why do we read the manual? Mostly to make sure we understand how the machine works. Is that a centrifugal advance mechanism or does it just look like one? Is that oil temperature switch open/off or open/on? Does it have a timing chain or belt? Not every detail is relevant, but the big details are rarely irrelevant.

Focus on the troubleshooting table. These are rarely complete, but they will usually list all the most common snags. What isn't covered in the table can be figured out if you know how the machine works.

Second up, troubleshooting requires active testing. Once you know how the machine works, there is nothing you can learn by sitting and staring. You have to start running tests. Consider the symptoms first. Is that backfire through the muffler or the carb? Is there a knock or a ping? Develop a mental list of possible issues. 

The most common example of such a list is the old "fuel, fire, compression" sequence mnemonic for gasoline engine troubleshooting. To run. the sequence, you must test each in turn. 

Which brings me to my third up item:

Only test or change one thing at a time. Don't go tearing the machine down willy nilly in hopes of striking it lucky and finding that one clear symptom that tells you what the problem is. What you're likely to find in that case, especially if the machine is getting worn out in general, is a bunch of unclear symptoms, any one of which could be the real snag, and you'll have to sort out which one by reassembling and testing again and again tediously. Try to keep the machine intact until you have some good clear reason to strip, and when you do strip, have some destination in mind that will help solve your problem. 

So, for instance, if you have a noise like a rod knock, but it could be a ping in your classic VW engine, don't strip it down to the rods until you've tested for pinging. The test for pinging, or preignition, is to retard the timing experimentally a degree or so at a time to see if it goes away. 

Fourthly, replicate. Scientists and engineers know that to know something for sure you have to keep testing until you've eliminated the possibility of a chance occurrence. So test it again, and again. retard the timing? The pinging goes away? OK. Advance it and see if it comes back. Then retard again. A few iterations and the likelihood of other hidden causes begins to diminish to an irrelevance. 

Fifth and last of all, sleep on it. Or rest. If you get tired, your brain will slow and eventually stop. The answer is more likely to come to you in the middle of the night after a few hours sleep than if you strip it down and reassemble it for the nth time without finding a damn thing. Or sit back. Look at something else. Drink a a cup of coffee. Take a walk. Eventually something, a new fact, a new idea, a new understanding, will make itself apparent and you can go back to the machine.

What should look for buying a 66 bug?

You can buy a repair panel for every part of the body, so it becomes a matter of cost-effectiveness. So if the 66 is $4k and needs $10K of work to be a nice 66, that's probably too much. But $4k and $6K isn't a lot for a fully repaired VW. It helps if you can weld and paint and rebuild engines.

How to change a Nissan Titan (first gen) front differential axle flange/cv flange

Our Nissan Titan plow-and-construction-and-farm truck has been popping out of 4WD. It doesn't move snow at all in 2WD, so this is a difficulty. Both the last snow storms have ending in me getting a tow from various neighbors. In each case it popped out after I had moved most of the snow, but still. It needed to be fixed. 

But, like most such things, it took a long while to diagnose the problem. It didn't help that in late fall, right about when the popping-out occurred for the first time, a friend had borrowed and accidentally driven the truck a long way in 4WD low, burning up the transmission fluid and blocking an internal solenoid temporarily. A "spill-and-fill" oil exchange procedure cured that problem, but it still popped out. (The buddy didn't know the transmission had to be in neutral to get from 4WD low to high.) 

Eventually, by studying up on all the online Nissan Titan maintenance forums, I discovered a likely candidate in the front left CV joint to front differential flange. Apparently a weak C clip, a design flaw, causes the flange to pop out, which causes the diff to quit turning. In some cases the tip of the shaft breaks off. But the 4WD warning graphic on the dash remains lit as if it were in 4WD. 

Here's a shufty of someone else's shaft showing the C clip (there's only one in the real item) and the tip broken off.

That little light was the eventual giveaway, although it took two days of study to figure it out. 

I just switched out the driver side front axle flange today. It would have been an easy job if my lift wasn't covered in snow and all iced up. As it is I'm well knackered. Winter is different in Maine, and my car lift is outside. 

Some dudes from warmer states on the Nissan Titan FaceBook group insisted it was just as easy to do the diff as it was to do the axle flange! Not likely, given how much snow and ice moving and thawing out of machinery I needed to do just to get this one little job done. I could just see myself slipping on the ice trying to carry the diff into my shop to strip it down. And where would I work? The shop is full with the tractor and the snow thrower. 

I also couldn't imagine finding enough time between snowstorms to switch out or rebuild the front diff. I need to move snow most weeks. 

But the C clip on the old axle flange was obviously worn out, so I'm glad I ignored the guys on the Nissan Titan forums and FaceBook groups that were telling me I had to switch out or rebuild the diff instead. 

Here's the part I bought from the parts house (their picture), showing the much beefier C-clip.

The FB dudes said that the spider gears would be worn, and they may well be, but that clip was the more proximate and obvious cause, and while the splines on the old flange were worn, they weren't worn badly. I expect the spider gears are in much the same shape. 

Anyway, here's the videos of the procedure. The first two are just of the difficulties. The last is of the actual spannering. My truck should be fine for the winter now. 

If I need to, I can still switch out or rebuild the diff in the warmer seasons.

 

Here's the procedure written out:

1. Remove left front wheel
2. With the wheel hub locked (screwdriver in the brake disc cooling holes, or put the right wheel on the ground), undo the big outer CV joint nut
3. Undo the ABS sensor. Have a bit of wire handy to hold the wheel hub so it doesn't pull on the brake flex hose
4. Remove upper ball joint and tie rod end split (cotter) pins and nuts
5. Tap the joints with a hammer or use a "pickle fork" ball joint separator to get them free
6. Undo the six 14mm head nuts that hold the CV joint/drive shaft to the flange. Move the CV joint out of the way
7. Pry the flange out of the differential carefully
8. Replace the seal. The old seal will pry out with a screwdriver. The new one can be tapped back in gently with a rubber mallet
9. Tap the new flange in with a hammer and a long bar or pipe. I had to pinch the c-clip a little bit tighter. It wouldn't go in at first
10. Everything else goes back on the way it came off. Be sure to torque the CV bolts to 54 pounds feet, to get the ball joint and tie rod nuts tight before backing them off to find the split pin hole hole, and to torque up the big CV nut to 100 pounds feet.

Enjoy!

How to check out a 1996-2001 Camry before purchase

For Rico on the FB Camry group:

Intelligent Tinkering:

Do all the usual tire-kicking: push down for bounce on the fenders, feel the oil for grit and look at the color, smell the ATF. If it's burned run away or bid it down to less than a K($). You can afford to put a good used or reconditioned transmission in at that, but it's going to cost, so you need the car to be much cheaper. Tires are a pretty penny now too. 

Check them for bad wear patterns that mean you have an alignment issue. Make sure the check engine light is not on or pull the codes and make sure there isn't a bad one. 

Listen to the engine, drive it until warm, listen again, adopt the lotus position and concentrate, listening for a ticking valve stem or a rod knock or a timing chain rumble. Then get it on a lift or jack stands and get a good flashlight or trouble light and go over it. The front undercarriage, control arms, suspension components, steering hub etc, cat-back muffler system, can all be replaced cheaply enough, so even if it is rusty it will all have to be replaced eventually, so don't let any of that scare you if it will be cost-effective, ie, if the car is discounted adequately to allow you to pay for the repairs, but the rear subframe has components that are replaced less frequently if ever and so more expensive and harder to get. 

Paint is expensive too, so, if you don't do your own, it should look nice or obviously be capable of being buffed up. The rockers rust at the front and the back six inches first. Just tap gently with a screwdriver. The front fenders rust out at the back where there's a few inches down at the road level. Lever the fender-liner out there and feel for heavy rust flakes and damp grit and salt. 

Make sure there are three studs of proper length on the muffler-manifold connection. They break when knuckleheads use impact wrenches on them. Manifolds are cheap enough but it's the kind of job that goes wrong because the engine to manifold studs break easily. Get the compression test numbers if you can. Then there's the little stuff that looks bad: The engine may leak oil from the rocker cover down on to the exhaust behind. This can be fixed with a new seal, but it is stinky while driving. A check engine light for an O2 sensor is nothing but looks bad. Make sure the AC works if you have some and the heater fan blows warm.

Series Land Rover outrigger repair

 This post salvaged from the old farm blog

I'm no Land Rover expert, but I've worked on a lot of cars and farm equipment, and this selection of photos seems like a pretty good step by step demonstration of the technique for replacing a rusted series Land Rover outrigger. I was looking for something like this myself, but couldn't find anything, and thus decided to make it. There were some useful tips to be found by gleaning the Land Rover chat rooms, some of which are represented here, but it wasn't all in one place. Now it is, and has become surprisingly popular, my most-read blog post in seven years of blogging about farming and science. Enjoy.

Make a comment if you have anything useful to add. (Comments are moderated.)

This particular vehicle is a 1971 Series 11A SWB (88-inch). If you arrived here after a Google search seeking how to do the repair, and are interested in how I acquired this particular car, enter "Land Rover" in the Google Blogger search engine, or click here. All the posts I have wherein "Land Rover" is mentioned will automatically be listed, more than you would ever want to read.

But the short version is, many years ago, when a young sprog, I was lucky enough to be a member of the famed Royal Air Force Mountain Rescue Service and, accordingly, rode in and drove Land Rovers on training and operations in the mountain and moorland areas of the British Isles. My RAFMRS mates and I are mostly in touch through FaceBook and through our exservice organization and journal, and between us we have more Land Rover stories than you can shake a stick at.

Once middle-aged, and financially able to occasionally indulge myself (only occasionally -- talk to my wife!), I realized I need a Rover, not only to make me happy, but for our farm and for search and rescue work, which I still do a good deal of here in the great and still very wild State o' Maine. So this old Rover actually gets used for all the purposes for which it was designed. I believe it outperforms many much newer vehicles in Maine's snow and mud. And, since I don't intend to ever buy another truck in my life, it will have to keep running for a few years yet.

Click on any of the pictures to enlarge them.

The first shot (above) is of the old rusty outrigger. The slot was cut to allow me access to clean out the mouse nests and rust on the inside, to see if it was repairable. I decided not, and ordered the replacement units which came very quickly, only two business days, from Atlantic British. As you can see from the second shot, Atlantic British are a BritPart outlet, but that's not all they stock, thankfully. (In the yUKe we say, "BritPart-shit-part.") The replacement outriggers are not one of the really bad BritPart products.

You start by removing the footplate, and then cut off all of the old outrigger and detach it from the outer end of the forward angle bracket using a cutting disc on a small hand-held grinder. Make sure to cut the angle bracket via its welds to the old outrigger, leaving enough of the bracket in place to weld to the new outrigger. Remove as well the long bolt that holds the outside of the outrigger to the galvanized sill channel. (At this point you'll wonder why Land Rover galvanized relatively inessential parts like the sill channel, and made the body out of aluminum, but didn't galvanize the frame. Go figure.) Be sure not to cut into the frame at this stage. You may need to cut out some rot later.

If you don't own a small angle grinder, you might manage by using a stick welder to burn the cuts and a sandpaper attachment on a drill to clean up the frame, but at some risk of a messier finish, and much longer to do the job. (This might be your time to buy an angle grinder.)

The bolt will most likely be stuck solid as a result of bimetalic (galvanic) corrosion. If you cut off the head (with a sawzall or similar), removing as few millimeters of the bolt guide as possible, you may then use the nut and some spare half-inch washers as a puller to remove the bolt. Take the nut off, put some washers on, and then put the nut back on and tighten it. Without a head, the bolt will be pulled out of its placement. You'll need a strong wrench (spanner) and cheater bar. It of course helps if you've sprayed the shit out of everything with penetrating oil and waited an hour or more. If you were deeper into your car and had already taken the bulkhead off, you might more easily do the same job by simply removing the lower door post and taking the assembly to a hydraulic press. If you had to cut them, buy new (half-inch by seven inch) frame bolts right away. You'll need them later. Be sure to get galvanized ones.

The inside of the outrigger may have corroded through the frame. This area needs to be tidied up with the grinder, and any debris inside the frame removed. (In my case there was a big old mouse nest, which was actually a relief, because that meant it was all relatively dry, although it was also disgusting to remove and made me gag.) If the rot here is more extreme than this, if it has traveled around more than one side of the rectangular section frame, you may need to worry about holding the frame straight while welding patches. You don't want your truck to start bending under it's own weight. Land Rovers will actually do this, if maltreated. It helps that the transmission is right behind, acting as a kind of built-in splint. Just be sure to do only one side of the truck at a time and in most cases you should be fine. If it's really bad, you'll need to examine the rest of the frame to see if it can be saved at all.

The BritPart replacement outrigger has a wide flange to take care of this kind of damage, but to my mind the metal is not thick enough, so you need a rectangular patch of thicker metal. I used 1/8 steel from an old American-style household oil tank. I have lots of this material left over from making a smoker out of the oil tank earlier in the year. Make this patch 5 and 7/8 inches tall to allow it to be welded to the edge of the six-inch tall frame, which edge is itself a weld and thus thicker, stronger metal. Weld this patch all the way around, but use a lower setting for the sides than for the top and the bottom. Sixty amps is fine, slow, but gets the job done without burning gratuitous holes in your frame. Here's the cleaned-up frame on my truck, ready for repair.

Here's what a completed patch should look like. In my case a patch was required on the passenger side but not the driver's side. Don't cover the frame holes if you can help it. These are useful for spraying corrosion inhibitor inside the frame. 

 

Once the patch is in place, or not, you need to grind it level and then you're ready for the new outrigger. Consult the Hayne's manual or some other reference to determine the exact placement relative to other areas on the frame on your particular truck. In the case of the passenger side, using some arithmetic, I worked out that the leading edge of the new outrigger was required to be 12.5 inches ahead of the trailing edge of the forward gas tank outrigger. If yours is a late Series II 88, this is the correct measurement. If it's a different model, look it up.

Use a large c-clamp to hold the new outrigger in place while you weld. You can snug up the c-clamp finger-tight and use a mallet to gently tap it into the perfect final position. If your bulkhead has been weakened by rust, it may have sagged as a result of the rusty outrigger, and you'll need to use a floor jack below the sill channel, and possibly a bottle jack located between the frame and the sill channel, to square up the outrigger and bulkhead and sill channel so the end of the outrigger is properly positioned, and so the seven-inch bolt is easily inserted. The frame is your best reference point, assuming it remains square. 

I learned how to make this adjustment the hard way, by not making it the first time I did this, and then having to force the bolt home. A small carpenter's square might help here. Once you have the outrigger in the correct position, and the bolt in place, weld the flange to the frame, all the way around. Finally, weld the end of the angle bracket back into place.

I ignored the extra width added by the frame patch, and so my Rover is now fully 1/8 inch wider than it was before. (Big deal!) It would be 1/4 inch wider if I'd needed two frame patches. If you're picky or a perfectionist, there are alternatives to this forced re-sizing: You could work harder to make a flush frame patch, or you could just use the replacement outrigger without a patch. Both would leave your Rover at its original dimensions, but the repair would be weaker. 

Here's the finished product, a brand new outrigger and reinforced frame where before there was a rusty mess. Now is the time to use a wire wheel to clean up the welds and then spray the heck out of everything with rust-proof primer and then rubberized underseal.

Again, some kind of corrosion inhibitor inside the frame is a good idea. I've even heard of guys parking the car on a steep hill facing down and filling the frame with oil via the drain holes on the rear crossmember, but I'm going to spray some product inside using a pneumatic sprayer and a long hose.

Learn. Fix. Drive. Enjoy.

Series Land Rover rear cross-member replacement

This post salvaged from the old farm blog.

After the fairly long-term success of my post on repairing outriggers (5,700 page views over four years and quite a few comments), here's another on the rear crossmember replacement job.

First, the preparatory work: This is a 1971 Series 2a 88 inch, LHD with the wheels removed. It's now on jackstands (placed forward of the rear springs). The floor, seats, seat box, and tub have all been removed. the rear spring shackles have been undone or cut off, and the differential gearbox and spring assembly rests on the floor jack (AKA "trolley jack" in the UK) or on blocks. The frame has been pressure-washed and brushed lightly with a wire wheel on a hand grinder to remove the worst of the dirt and any loose old finish.

Here we are measuring to record the distance between the front and rear outer tub brackets. We'll keep this measurement the same when we put on the new crossmember. Lots of people advise using the tub as a jig to set this measurement, but to my mind that runs the risk of shortening or lengthening the distance between the front spring mount and the rear upper shackle anchor, which helps set the rear wheel alignment. The tub is flexible, and could be squeezed into a different shape, throwing these measurements off.

As it stands, the passenger side is actually 1/4 inch longer than the other due to a slight driver-side fender-bender. We'll fix this when we fit the new crossmember. The final target measurement to square up the truck is is 48 and 3/8 inches.

We also measured the difference in height between the cross member and the flat top of the frame using a level as a straight edge. We'll keep this measurement the same too, at 1 and 3/8 of an inch.

Then it's time to cut your Rover up! Not for the faint of heart. I started with my 7 inch grinder. My new crossmember has 16 inch frame extensions with four inch welding tabs, so I cut the frame just shy of 12 inches from the old crossmember. 

The heavy duty grinder proved too clumsy and in fact broke a cutting disc off, so we finished with the 4.5 inch hand grinder.

Once through about three quarters of the way, we position jack stands under the old crossmember to catch the weight. Leave these about a notch lower than the crossmember. After a while the old crossmember will bend down, or can be pushed down, to rest safely on the jack stands. This allows you to finish the cut with a hacksaw from the top, which is easier and safer than using a hand grinder from below.

Once  the old junky cross member is removed, it's easier to burn out any old shackle bushings. Use a gas torch to burn out the old rubber, and the inner bushing can then be pushed or pried out. 

You then cut through the outer bushing metal with a hacksaw, being careful not to cut into the spring itself. The new crossmember comes with shackle bushings installed, so unless you plan to remove and/or service the spring or diff too, you only need to buy two new ones, but you may need some new bolts and nuts too, and perhaps new shackle irons. (Remember, only the inner shackle iron is threaded.)

You now have a once-in-a-Landy-lifetime opportunity to rust-proof the inside of the frame easily. Here I'm using Fluid Film, popular here in New England where we use a lot of winter salt on the roads, a proprietary Fluid Film air-powered product dispenser, and a long piece of hose which reaches forward all the way past the dumb irons, but you could use Waxoyl or similar.

First, test where you can see to make sure product is coming out in a suitable spray pattern. Start spraying with the hose fully inserted, then withdraw the hose an inch or two at a time. Repeat to be sure of getting enough product in there.

Now turn your attention to the new cross member. Bend the welding tabs out gently with a mallet and test fit it to the old frame. Using trial and error, get the best fit. Reproduce the old measurements above and clamp it in place, then tack weld it.

This is the bit where the old-timers say to fit the tub, and use the tub as the final jig to get the measurements right, but that ignores my objection above, and it requires that you put the tub on and take it off again to weld the top of the new frame extension. This is too much trouble for me, and indeed, my tub isn't square anyway.
   

Instead I relied on careful measurement. I then welded all around each side, and up and down the tab slots. You can easily tighten any gaps between the tabs and the old frame with a hammer once you start welding and get everything nice and hot.

Now, if you're brave, measure again! Mine was within a sixteenth of my target 48 and 3/8 inches, so I was pretty happy with that.

Having reconnected the shackles, my plan now is to spray everything I see except the transmission with POR 15 rust proof paint, and Fluid Film on top of that.

That should last a while. Enjoy.

Toyota Camry (manual transmission) clutch issues

Question: I have a 96 Camry won't go in gear: If I switch the car off then put it in gear it works but doesn't want to change gears while driving. Could it be the clutch plate? Help!

Intelligent Tinkering: First, check to see you have some fluid in the clutch master cylinder reservoir. If not, or low, put some in and pump away on the pedal to see if it begins to shift easier. If it does, you have a leak somewhere. Then, if filling and pumping doesn't prove a leak, if you can see the slave cylinder, get a buddy to pump the pedal. As he does that, you watch to see if the slave cylinder piston is actually moving the forks. I've never been under the hood of a manual Camry so I don't know if you can see the slave cylinder. If not, bleed the clutch before you do anything else. If you can prove to yourself that the clutch master and slave cylinder are working, then you may begin to decide you need a new clutch, but not until.