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Tranny downshifting hard into 1st gear

I have a 90 Cutlass Cruiser SL and it is shifting real hard going down to first. Other gears are fine. Checked motor mounts, ok. Also stutters at higher speeds in OD but when I kick it down to drive it quits. She has a lot of miles but I can’t afford a new car.

Step 1 is check the automatic transmission fluid level if not already. Also if its dark or burnt smelling change it out.

New filter and fluid.

How many miles since the last transmission fluid change. (you really should change it BEFORE there is any indication of a problem. )

This sounds a bit like what my Caravan does, though mine is not what I’d call an objectionably “hard” downshift. At a recent fluid/filter change, my transmission guy did a test drive to check the downshift…he said he noticed that the speedometer didn’t drop fully when coming to a stop, and he thought that might be related…ie, that a sensor was transmitting incorrect speed info to the transmission control. In other words, that the problem is not the transmission itself but rather the information it’s receiving. Not sure if he’s right, but the downshift was unchanged after the fluid change, and it’s not gotten worse. Mine is so minor that I’ve not made it a priority to investigate how the car reads wheel speed…I suppose there’s a sensor somewhere that does that. I have higher priority items to work on first!

So watch your speedometer as you are slowing to a stop and see if the needle seems to be hanging up. Regardless, the fluid/filter change is important routine maintenance (every 30k), so start there as advised by @raj and @Spanky2012.

Changed fluid about 1000 miles ago. Ran fine and it just started out of the blue. Changed a motor mount and thought that might do it, not. Even thought about buying a code reader and see if that would tell me anything, those ain’t cheap either.

Ooops, I see I wasn’t careful about names…duhhhh.

Its 22 years old. Beyond changing fluid/topping off you can get the codes read by a reputable place.

Your transmission is not electronically controlled, so there will be no codes to pull related to the transmission. Based on your description of the problem, I think you may have a torque converter clutch solenoid getting flaky. I had to replace one in a 1990 Buick Skylark I used to have when it refused to unlock the torque converter when I came to a stop, causing the engine to stall any time the car was stopped and the transmission in drive. It was maybe $50 in parts, fluid, and gaskets and a couple hours of my time, and gave me another few years of trouble free service before rust took its toll on the rest of the car. It’s a fairly common problem on GM vehicles of this era and is usually not terribly difficult to replace. You have to remove the side cover to get to the TCC solenoid, so hopefully you have decent access. It was easy on my Buick.

Maybe there is a detent cable that isn’t connected or is rusted in the wide open throttle position. This kind of thing has happened before. The cable keeps the transmission from upshifting too soon if you are accelerating hard. When it’s stuck, it could cause delayed downshifting to first and it would make the eventual downshift seem violent.

Also, what they said.

Ok explain what you mean by downshifting hard into first. When is this happening?? Is it happening when you are slowing down to a stop?? Be more specific.

transman

Things that have given me a shimmy and hard shifts in the past were not even trans related. It was a miss in the engine when I went into od it would shimmy.

Huh???

transman

There is only two times where an automatic transmission goes into first gear. Once when you drop the shift lever down to the D or L positions and when you are cruising and slow down to a stop. When is it shifting hard to first??

transman

when it is supposed to but it has a very noticeable clunk. Someone said something about a sensor that may have something to do with it. Do you know?

When stopping when the tranny should drop into first it gives a hard clunk or jerk. Once stopped it idles fine and shifting up it shifts smooth as ever. I had it do this clunk like this before and it was a broke motor mount. Mounts are all good.