auto maintenance February 07, 2018

The Disappearing Dipstick

Another dumb idea is making its way through the auto industry. The automatic transmission dipstick, which serves as an under-hood point to both check and add transmission fluid, is being eliminated on more and more models.  Some European manufacturers (Mercedes, BMW, and Audi) are taking it one step further and eliminating the engine oil dip stick as well.

The first vehicle I saw this on was the mid-nineties Isuzu Rodeo and its sister, the Honda Passport. Instead of having a transmission fluid dipstick, the transmission pan has two plugs on the pan underneath. You have to pump fluid in one plug and wait until it just trickles out the other plug, of course being sure that the vehicle is warmed up, level, and that the moon is in the correct phase – more on this later. Although it was a bother, this new method was pretty straightforward, with the plugs clearly marked and identified and a simple understandable procedure. But you, the consumer, were now effectively locked out of your transmission.

The next vehicle I saw this on was a VW Jetta, where the transmission fluid-check procedure was something like 63 steps and involved the use of a multi-thousand dollar scan tool to verify the transmission’s mode and temperature before checking the level. If fluid is needed, a plastic cap must be broken off the “add” tube and replaced with a new one. Hope you live near a VW dealer. Up to that point I wasn’t too concerned, because Isuzu had had issues with their transmission prior to eliminating the dipstick (there was a metal tag on their dipstick cautioning against overfilling), and VW’s fluid was so unique (made from the pressed bladders of rare Siberian yaks I believe), that they might have thought this was for the best. But when GM did away with the transmission fluid dipstick on some of their standard sedans and I found no transmission dipstick on an ‘02 Ford Explorer, I knew the fungus was spreading out of control.

You broke it!

The official industry argument for this trend will be as follows: “Our research has indicated that X percentage of transmission failures are caused by incorrect filling procedures and incorrect fluid. By precisely controlling the fluid in our transmission we can ensure superior life and performance.” Translation: “The problem isn’t that we built crappy transmissions, poorly engineered, with low-quality parts. The problem is that you put fluid in them!” This argument is easily refuted by the fact that fluid stored in the freely sloshing pan of a machine (your car or truck’s transmission pan or oil pan) changes levels dramatically with each start, stop, or turn of the vehicle. And let’s not forget about hills changing the fluid level. And yes, the phases of the moon will create a “high tide” and “low tide” within the transmission pan.


So if precision engineering is not behind the disappearing dipstick, what is? I have two theories. Premature transmission failures on American cars and trucks are reaching epic proportions. By making it impossible for consumers to check the fluid, they can then be blamed for not checking the fluid. If they produce records indicating the fluid was checked (outside of the dealer, of course), well, it couldn’t possibly have been checked correctly, with all 63 steps followed and special adapters used. Kind of like filling out a tax form. So the manufacturers are off the hook again. This may sound a little cynical, but it is well-deserved cynicism.

The other, more likely, theory is that by eliminating the dipstick, tube and all, a savings in production costs is achieved. The same basic transmission may be used in several different vehicles, or “platforms,” as the industry calls them, but for each different vehicle the dipstick tube engineering is a little different. It might be on the right side or the left side, higher or lower, all depending on the contours of the vehicle it’s going in. By making the transmission fluid check-and-fill procedures part of the transmission itself, less re-engineering has to be done to make the transmission fit different vehicle models with no re-engineering.

From worse to worst

Several years ago a woman stopped at my shop (a different shop in a faraway galaxy) with a 2-year-old BMW, because an oil warning indicator had come on, scaring the bejeezus out of her. I popped the hood to discover that there was no engine oil dipstick. After making sure no one had stolen the dipstick, I consulted the owner’s manual.  I like to believe I have fairly high reading and comprehension skills, but it took me a good 10 minutes to figure out how to use the dashboard’s digital display to check the oil level using the high and low oil level sensors now placed within the oil pan. So in a very well thought-out scheme, they have replaced the unflinching reliability of a dip-stick with electronic sensors riding in a bath of very hot oil with hydrocarbons mixed in.  Sometimes engineers enthralled with their own cleverness do things simply because they can, but there are supposed to be adults in the room to stop them.

On deaf ears

This is the part where I make the heartfelt appeal to the manufacturers to reconsider this bit of engineering by considering the real-world effects. Do you really think the world would be better off if no one can check their oil easily or add transmission fluid to a car or truck?

What about the middle class family with four kids, two of them in college? They’ve got a fleet of three- to ten-year-old cars they have to keep on the road. Yeah, the old truck leaks a little transmission fluid, but they put a quart in every two months and it does fine. Do you really want to make that impossible to do? Do you think the consumer will marvel at how clever you are? More than likely they’ll say “I’m never buying one of these again!”

Sign Up for Our Newsletter

Keep up to date with coupons and promotions


Get exclusive access to them all when you sign up for our newsletter.

Ezytire Toolbox