Is this how I killed my automatic transmission?

I recented destroyed the transmission in a '98 Mazda 626. The mechanic who looked at it told me that some part inside exploded and sprayed shrapnel all over the inside of the transmission. I was trying to figure out what I could do so that that doesn’t happen to my new car’s transmission, and I noticed a habit I had when I drove the Mazda: when I’d back up out of a parking space, I would put the car into drive before it had completely stopped going in reverse. The car would roll a few feet backward after I’d put the car into drive.

With this new car I’ve quit that habit. Now I wait until the car has come to a complete stop before putting it in drive, and I wait a second or two after putting it in drive before I hit the accelorator. Lately I’ve noticed that everyone I know has the same habit I used to have, so it seems pretty common. Hopefully I’ve described it well enough so people know what I’m talking about.

The question is, am I right that this is particularly hard on a transmission? Is that something that could have, over time, contributed to the transmission blowing up (I had the car for three years, and put 65,000 miles on it)? If not, does anyone have any tips on how to treat your transmission better than I treated my old one?

It’s probably good that you quit doing it, but my Ford Windstar had a part inside it that exploded and sprayed shrapnel, and it only had 23,000 miles on it. Sometimes a part just gives out.

FWIW, my father always said that if I shifted from forward to reverse or back without being at a full stop, I’d blow out the CV joints, not the transmission.

Seems to me the most strain would be on the torque converter (or the clutch, in a manual tranny), not the transmission itself. I imagine that the fins inside might be stressd to failure. I can’t see why the CV joints or any other drive train component after the transmission would be affected.

No idea whether it does damage, but my pathetic Nissan gives a nasty snarl if it’s not completley stationary when you move to Drive or Reverse.

This would strain the torque converter, and in an extreme case might cause the transmission fluid to heat up, but it woudln’t cause anything to “explode and spray shrapnel”. Remember, though, there are a bunch of bits spinning around in fluid with all sorts of stress concentrations built into them. Any small manufacturing defect can cause this kind of failure. :eek:

It isn’t good for it, but it shouldn’t have caused the problem you describe. Just so you understand, unless you have a torque lock (which activates at speed) there is no direct mechanical linkage from the the engine to the wheels. The torque converter uses the motion of fluid inside to transfer torque from one spinning plate to another without actually coming in contact. With a manual transmission you can strip gears, split splines, or bend shafts, but this basically shouldn’t happen with an automatic. Not that you can’t screw it up, but not in the same way as a manual.

Things to do to protect your automatic (planetary gear) transmission:
[li]Reduce the severity of shifts[/li][li]Don’t shift into low gear unless you really need to (towing or driving on ice)[/li][li]Put it in neutral or park while idling for long periods[/li][li]Don’t ever, ever, ever do a “neutral drop”[/li][li]make certain the fluid is topped off, and have it replaced at the recommended service intervals[/li][/ul]

The last line is a little in question, as some mechanics (rightly) point out that replacing the fluid can do more harm than good in some cases, and argue that you shouldn’t replace it unless it looks gunky or has a lot of particulates in it. Right now, I don’t know that there’s any definitive answer one way or the other, so all things being equal you should probably follow the manufacturer’s suggestion (usually ever 30k or 60k miles.)


Okay, so what is a “neutrad drop”?

What’s a neutral drop?

(on preview what he said… mostly)

Not a 100% on this, but I’m pretty sure he’s talking about revving your engine in Neutral and then "dropping it " into gear for the added torque you would grab at…

btw, I own a '93 MX6… she’s on her last legs as well, but she’s been real good to me and I try my best to return the favor. But to get to the point, I would think any vehicle could benefit from a tranny cooler and if you d-o spring for one don’t get the cheapy kind that have fins like your radiator, spend the extra bucks to get one with stacked plates in them. I purchased a little one made by B&M. If you’re super serious about tranny health you could always check and see if there’s a secondary filter type kit for your model.

My ATX transmission is supposed to go out around the mileage I’m at currently and I have yet to install the cooler kit (no cash) so you know, I’m nervous lol. I’ve never had a problem coming to a complete stop and all… if you want to change gears sooner you’re just going to have to slam your brakes more, haha. I don’t “over-wait” , but my car is stopped when I shift down. I guess this tranny explosion isn’t your fault TH, but you’re welcome to post the same Q over @ If you still own a 626 that is. later

There’s some misinformation and bad advice in there. There’s really no serious question about servicing transmissions at the recommended intervals.
The only cases where changing the fluid can precipitate a problem are those where the fluid has severely deteriorated from not changing it. And the time to change it is before it breaks down – to suggest that it shouldn’t be changed unless it looks bad is ludicrous. The main point in changing it is so that it doesn’t get to looking bad. I don’t know who you’re hearing that stuff from, but they don’t what they’re talking about.

Exactly. A high school mate did this with his Malibu…which explains why he had to have the transmission replaced three times. Because of the torque converter you can actually get an instantaneous torque multiplication factor (because you spin up the fluid), which can put loads on the gear set that are way past the design loads.

You’ll know, when you hear it start whirring but not going anywhere, that you’ve done a number on it. :smiley:


I don’t think automatic transmissions are delicate devices. Sure, it’s better to come to a complete stop after backing and before shifting into drive, or vice versa, but you can’t be going all that fast and I see no reason why it should destroy a part.

Drivers abuse their cars in lots of ways and they still go for 100000 miles.

Probably a latent manufacturing defect but you would have one hell of a time proving it.

Not just the torque converter. Automatic transmission use plantary gear sets. [way over simplified explantion due to time constraints] In a plantary set there is a sun gear, some planet gears arranged around the sun, and enclosed in a ring gear. If you stop one (brake) and put power to a second, you will get a speed change out of the third. If you lock any two of the gears together (clutch, freewheel) the entire unit rotates as one piece.
So if you are going backwards and drop it into drive you could have something rotating the wrong way and stessed way beyond design limits. At this point things can break.
If you look it up, this is considered a bad thing.

I guess it might be an American thing but I expect more than 100,000 miles out of a transmission. My late 92 Voyager went through a tranny for the last 3 years we had it (failed at ~160,000, 200,000 and 240,000 miles). I won’t ever touch a Chrysler vehicle ever.
My dad’s friend abuses his tranny in a unique way. He taps the throttle continuously when driving. To the point where I get motion sickness if I think about it (this is coming from a guy who does auto-x and tracks days with my Matrix). He just went through a tranny on his 96 Windstar (of course it could just be because it’s a Windstar).

And disable the overdrive if you’re towing.

I’ve heard that most automatic transmission problems crop up at one of two points:

  1. Between 80,000 and 120,000 miles
  2. On the high side of 180,000 miles.

This was anecdotal, and an impression I developed from speaking with a number of mechanic types.
I assume these guys were excluding failures under warranty, which I consider infant mortality anyway.

For the record, I had a 98 Escort in which the transmission got fuxored. Twice. Not in the manner you describe, but it pretty much stopped working right.

I bet JW will look it up but…I have a hunch that the 98 Escort and your 98 Mazda might have the same crummy transmissions and you were doomed from the get-go. Ford owned Mazda at that point, right?

I’ve heard that most automatic transmission problems crop up at one of two points:

  1. Between 80,000 and 120,000 miles
  2. On the high side of 180,000 miles.

This was anecdotal, and an impression I developed from speaking with a number of mechanic types.
I assume these guys were excluding failures under warranty, which I consider infant mortality anyway.

What do you mean by “over-wait”?

I’ve noticed something in my auto transmission lately that has me curious. Every once in a while, and only when it’s cold, when I come to a stop and then immediately try to go again (e.g. for a stop sign), the engine will rev, but there’s no drive. If I back off the accelerator and give it a moment, it goes back to normal, but if I’m not quick enough in backing off, it clunks pretty hard and lurches forward, then everything’s normal. Can anyone comment on what this might be?

Sorry for the double post. My proxy server led me to believe that I had failed to post the first time.
Actually, ZipperJJ, the '98 626 has a CD4E. Your Escort had a F4EAT, assuming it was made between '89 and 2000. If it was an '01 it would have the 4F27E. The 626 and the Escort wouldn’t generally use the same trasmission, as I believe the 626 was heavier than the Escort and had stronger engine options.

You are correct that Ford and Mazda have a relationship, but it’s not a holding company relationship. Ford has a substantial but minority share in Mazda, 30% last time I checked. I believe Japanese politics might make Ford disinterested in owning more. It’d be like Daimler buying Chrysler or something, except… back in the 1950s.

If I recall though, the general consensus on the 626 is that its transmission is… adequate. Not quite terrible, but not good. I think it was being asked to perform at the absolute outside edge of its design specs, which never helps anything.

I know nothing about the trannies in the Escort, expect that yours fell down and went boom.