Transmission 'grabs' when slowing to a stop

This happens when decelerating from highway speeds (60mph), most commonly when exiting a freeway. At about 10mph, the ‘grab’ happens for about half a second. It is not violent, but it is definitely noticeable. It does not happen when driving in city traffic at 40mph or less. Any ideas?



'92 Dodge Stealth, 3-Liter V-6, automatic, 138K miles

What do you mean by grab? Is it downshifting?

It’s possible, but the ‘grab’ has only been happening in the last year or so (I’ve had the car 10 years). Before that, deceleration was smooth, no ‘grab’, from highway speed clear down to a stop. I’ll try to watch the tach tomorrow, see if it indicates the downshift at the same time as the ‘grab’. Thanks.

How long’s it been since you changed the transmission fluid?

I’d imagine that what you’re feeling is a hard downshift. And the first thing to ask about is fluid as shadowfax noted. Check it. Note the level, color & smell. If you find it low bring it up to level - using ATF+4 ONLY. Then have the leak addressed.

But if the transmission has not been serviced regularly then maybe think about this being the beginning of then end (though then end can often take a really long time). Especially think about the end if the fluid is dark and/or smells bad. That said, a servicing of the transmission now won’t hurt (but might not help either).

Keep in mind when servicing it to get the fluid exchanged, not flushed.

I just wasn’t even going to go there!

I would have the TCM scanned to be sure the problem is not electronic.

transman

Good Plan. Do These Have The Infamous Input And Output Speed Sensors ?

CSA

The transmission fluid was changed at 126K miles, March '09.

Could you decode that acronym for me? TCM = ??

I have had electronics go bad in the past. The main computer card cost $1K for the part!! The ECS (Electronic Controlled Suspension) controller went bad, causing an engine miss condition. That one was really hard to troubleshoot.

TCM is “transmission control module.” In this case it basically means getting the ECM (engine control module) onto the right kind of scanner - initially one that can pull error codes. Then, if need be, the right kind of tech with the right kind of scanner can find out exactly what the transmission is doing.

By electronic the first assumption wouldn’t be that the TCM itself is the problem - rather one of the things involved in the electronic control (such as the speed sensors mentioned above, or solenoids or the like).

Thanks for the info. I will have my mechanic look at it when I am in for my next oil change, probably late January/early February.

Also, thanks to everyone for responding.

A regular mechanic will probably not have the equipment or expertise to check it out. IF the shop has the right kind of scanner they can check for error codes. But they are unlikely to get past that - unless they have a dedicated transmission specialist. Ask at your regular shop about it but you’d probably want a dedicated transmission shop.