Today, whilst browsing Facebook, someone on a Jeep page posted a vehicle diagnostic tool I’d never seen before. It’s not a 500 page factory service manual, it’s not some huge online database, and it’s not a YouTube video — it’s much, much cooler. Check out this circular slide-rule transmission diagnosing tool.
I’m not even sure what to call this thing. It sure does look like a circular slide-rule, though that’s not exactly what it is. It popped up on the CJWCR – Club Jeep Willys Costa Rica – 1994 Facebook page, and since we’re in a mad-rush to try to hit our biggest month ever here at The Autopian, I’d be a fool not to at least turn it into a mini-blog on this fine Saturday.
Check it out:
From there, you rotate an arrow into the right position such that it points to the issue the vehicle is facing.
If the transmission is locked into a gear, you rotate the arrow to about the 6 o’clock position shown in the image above, and you choose which gear it’s locked into — drive, reverse, or low. If the parking pawl won’t hold the vehicle in place, you rotate the arrow clockwise a bit farther.
If you keep spinning the center circle, moving the arrow clockwise you will point to “engine won’t start by pushing.” I have no idea what this is all about; will the little rectangular window that denotes items to check read “THIS IS NOT A MANUAL TRANSMISSION”? Perhaps?
There’s a “trans overheats” issue on the circumference of this diagnostic circle, there’s a “severe engagement” section broken into low/drive and reverse (i.e. if you put the shifter into these and you feel a CLUNK).
The shift conditions section makes up over 90 degrees of this service guide-circle, and allows one to point to kickdown issues, severe shifts, no shifts, engine revving too high, etc.
There’s also a “slippage or chatter section” for various gears, and there’s a “no drive in” section if the car doesn’t move at all in drive, reverse, low, or all three of them.
I wish we could see what the little window would recommend for each issue, but the “severe 3-2 shift” shown in the photo yields a “KLEJb” message, with the lower case letter indicating something that requires a transmission removal. K is engine idle speed, L is vacuum control unit, E is valve body, J is the front servo, and b is the rear clutch that requires transmission removal.
Unsatisfied with this sole picture of the diagnostic slide-rule, I dug up my old full-size Jeep service manual to see if I could learn a bit more about how one would troubleshoot each issue:
As my service manual is from 1984, the automatic transmission in it is likely a Chrysler 727 (though I’m a bit confused why the Kaiser Jeep slide-rule says “Borg Warner” given how few Borg Warner automatics Kaiser Jeep used):
Anyway, while it’s not as fun as a circular slide-rule, this look-up table pretty much walks you through which checks (denoted by letters) one should do in which order (denoted by numbers) for each issue (mentioned on the left side).
I think the table above was for in-vehicle diagnostics, while the one below is for if the transmission is out of the vehicle:
Anyway, I just figured I’d show you that fun circular service guide, which is not only useful and quick to use, but fun! It beats boring look-up tables or spreadsheets or other digital diagnostic tools; I wonder if there are more beyond just for the automatic transmission….
Top Image: Jeep via CJWCR – Club Jeep Willys Costa Rica – 1994 (Facebook)
Old automatics (like the original Hydramatic) had a rear pump so that the car could be started by pushing. When electric starters became reliable enough, it was deleted as a cost cutting exercise and the era of not being able to push start an automatic began.
Huh, TIL.
(It must be tricky owning a beater that you can’t push start, I’ve had to resort to it a bunch of times)
Back in the day, “On Board Diagnostics” meant On Cardboard.
Dave is such a young pup. Back in the day there circular calculators were nit uncommon for a number of “find the fact” applications.
You have to wonder if similar tools were used by SAC (Strategic Air Command) back in the day.
Set outer wheel to “Ruskies invade Alaska”, window says “Launch the nukes”.
I looked around the cockpit of my B-52, but it was Slim Pickens.
A fella could have a pretty good weekend in Vegas with all that stuff ….
I Strangely Love this reply.
Thanks for the laugh!
Thank you. Most of what I reply to is to make people get a laugh. Sometimes, it’s about my love of Peugeot 504s, Saab 9000s and Honda Accords, but usually it’s to try to lighten someone’s day.
Like this
Sweet tool. Wasn’t the 1963 Wagoneer SJ the first Jeep to have an automatic?
Save the (230 OHC) Tornados!
The user’s and repair manuals for Mercedes in the 1980s used the same typeface as the one in the tables in DT’s Jeep manual. I wonder what it’s called.
Looks like Univers.
Great find, thanks!
I’ve never quite figured out the point of simple slider-cards like this. Or rotator cards, as the case may be. It’s really no more or less useful than an ordinary table, like the ones shown in the service manual.
Compare this with a little wallet-sized “forever calendar” i had as a kid: on one side it had two concentric circles that you could rotate around to select the current year, and a pattern of interfering cutouts on the two would reveal exactly one coloured symbol underneath, and that symbol would be different for each position of the two circles. On the flip side, a single circle with a cutout large enough to reveal one month worth of day numbers printed in a spiral would be spun around so that the current month points to the symbol you found on the other side, and you’d then see the correct days of the month in the familiar 7-day-wide grid.
If you’re interested in calculating devices that are actually clever and novel, check Chris Staecker on YouTube. There’s a whole rabbit hole there to get lost in.
One benefit of the slider-card is that it only shows that line of the table. The table in the manual makes it really easy to glance at the wrong line, possibly confusing the diagnosis, etc.
Fair point. Try to keep is as dummy proof as possible.
I had a printed service manual for my 2012 Acadia.
It had 4 volumes the size of phone books!
The transmission section was most of one volume.
Phone book-sized as a unit of measure is even less relevant today than it was 40 years ago, even when disregarding the variability of location-dependent beefiness.
Related: how many Autopians remember the trope, never mind the reality, of a phone book used as a booster seat at the dinner table?
I grew up in a fairly rural county and the phone book was useless for that purpose. The Sears and the Montgomery Ward catalogs, stacked on each other, were far more helpful then.
Exactly my point.
The local phone books of my youth were a half inch thick, at most, even after the format size was reduced significantly.
Ha, yeah. My dad grew up in Detroit during the Depression and learned to drive his dad’s 1928 Oldsmobile, around 1940, at the age of 12 and got his driver’s license at either 13 or 14 but since he was quite short (he experienced a great growth spurt after he enlisted in the Navy in WWII and had better access to nutrition) he would attach wooden blocks to the pedals and sit on one or even two Detroit phone books. Many years ago I actually came across a ’40 or ’41 Detroit phone book and that was one heck of a thick tome, all right. Yeah, football fields may still persist as a standard of scale but phone books have indeed gone the way of the dodo.
These stories are why I love this site. Maybe some of the stories we tell are boring, (not that yours was) but it’s nice to have a place where we can tell them and not get shredded by angry people.
We did that. The joke in our family was that the town my mom grew up in, was so small that you couldn’t use the phone book for that.
What’s a phone book?
Wait till you see how girls can present complex information by folding paper into four quadrants and making you pick numbers.
But it usually just said who you had to date or whether she had a crush on you….
Cootie catchers is what we called them
Where I grew up, we were kind of co-ed about those. Any chance we got to be engaged with a girl we liked was okay.
From there, I went on to making paper airplanes. That was fun too.
Wow! This is something I’d find at a bazaar for a buck, wonder what it is, take it home and play with it for hours, and then go out and buy a Jeep.
I think the technical term is probably calculator.
There is one made to troubleshoot the deliberately misleading, useless food information on American food packaging.
You think fat percentages are on the label, but they are not.
Hence the device for food.
Brilliant!
Frankly throw out the manual and use the circular help. This should come with every car sold.
Hopefully you can get a hold of one of those things; it’d be mighty cool if you were to disassemble it and post pictures so we could print them out and make our own even though not many of us actually have Kaiser-era Jeeps with automatic transmissions.
Speaking of automatic transmissions:
“If you keep spinning the center circle, moving the arrow clockwise you will point to “engine won’t start by pushing.” I have no idea what this is all about; will the little rectangular window that denotes items to check read “THIS IS NOT A MANUAL TRANSMISSION”?”
Some older automatic transmission vehicles could indeed be push-started. When I got my first car, a twelve-year-old ’74 Volvo 144 with a manual transmission, I acquired a Haynes repair manual (with a great cutaway illusration by Terry Davey on the cover) which noted that prior to 1970 Volvos with automatic transmissions could be push-started. Currently I’m DD-ing my kid’s 1983 Mercedes 300TD which has an automatic transmission; its glovebox manual lists a slightly complicated procedure for tow-starting (!!) which involves shifting between “N” and “S” (instead of “D”) and also mentions that “the same method can be used to start the engine in emergencies when rolling downhill” (ha, yeah, as if tow-starting wasn’t in itself an emergency.)
Indeed. Note that item “e” to check is “rear pump” I don’t know about Jeeps, but Chrysler automatics had the second pump through 1965 and could be push started. A nice bonus is that if the engine stalls, the power steering keeps working.
Yep, this right here. I think some Powerglides also have a rear pump and can be push started – it was more common in early automatics.
I really miss Haynes manuals.
Does David know it’s the weekend?
To your point, let’s look at the data. The low hanging fruit to raise the site’s stats is relative to posting more on weekends.
This brought me joy
So? People still read on the weekends…
Yes as a rarely known fact newspapers use to come out every day. Now that they are online it’s like 3 days a week. Computers made everything worse despite promises of no work, unlimited sex, perfect bodies, unlimited free time because everyone forgot if you program a computer you need an expert at programming AND an expert at the subject being programmed. Computer programmers have no outside experience. That is why self driving cars and really anything gets worse when automated
Huh?
I understood 1976fiatspyferfan perfectly. To sum up, computers did not make life simpler, but more complicated.
Never expect relevancy, nor even coherency, from certain commenters.
I still check the site on the weekend for nuggets of vehicle articles and such. As much as I’d like lots of articles on the weekend as well I like the authors having a break during the weekend and more of a break during the week (via them not having to write extra articles during the week.
Honestly I’m genuinely concerned that in my lifetime enthusiast automobiles will get basically regulated out of existence (in the US) and we’ll all be stuck with self driving pods for using public roads, we don’t need to burn through the old content that isn’t getting made any more any quicker.
Not a snowball’s in chance Hades of that happening in the US. Too car-dependent, too rural, too poor, and too unwilling to be told what’s good for us by the Gubermint.
Europe though? Oh yeah, I see gas cars getting banned sooner than later.
If you want to dominate the world, persuade your enemies to adopt deadend technology.
Best case, they end up broke and without transport.
As the Russians say, easy as cake!
Dead-end technology is a matter of opinion. There are many use cases where energy density matters. If an EV works for you, great! If it doesn’t, that’s fine too.
I see no reason to replace any of my *5* paid-for, efficient-enough cars any time soon. The capital cost to do so FAR outweighs any possible savings, and I have done my part for Mother Earth by not breeding anyway. The best solution of all is to re-arrange your life to significantly drive less.
+1 for not breeding
At the end of the day, the real problem on this planet is the huge human infestation.
Children are just too easily created by unskilled labor.
“…it hides a shining car, a brilliant red Barchetta from a better managed time…”