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Discussion Starter #1
91 NY Fifth Ave -- most of the time it's fine, and as long as I'm gentle on the throttle during acceleration and deceleration, shifts are nice and smooth.

However, from time to time it will shift more 'noticeably,' and I'll hear and feel (slightly) a clunk... I think this has something to do with where the gears in the trans are in relation to how hard I press the pedal or something like that, I can't really say for sure.

Anyway, my question is: Is this pretty normal for these cars? And, will the updated computer help it stop doing it? I'm almost positive it's doing it because of the way I'm using the throttle.

It did it earlier today, I think I was coasting (in drive) and pushed the gas. Maybe my foot was a little too heavy? I think I've heard it do that even if I was very light on the throttle as well.

Thanks
 

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mine only acts stupid when i drive a long way and then back into a drive way. It clunks. I have never had clunks on normal driving in a straight line from start to stop. I actually cant say i have even noticed the clunk in reverse since putting a transmission cooler on.
 

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No, clunking is not normal. As I posted before rough shifting and the clunking are usually signs of low fluid pressure inside the transmission. A revised TCM will help if the problem isn't bad.
Many times these hard shifts/clunking and bump shifts set a "soft" error code. The computer will allow so many "soft" error codes in a certain time period before it sets limp mode. That is compared to a "hard" fault which will set limp mode after a single time.

You should not have to drive the car gently to get smooth shifts. There's a problem there and the earlier you address it the better life expectancy the transmission will have. I've never babied an A604 and the shifts remain smooth.
This is all assuming the transmission is the fault of the clunk. There are suspension and engine/transmission mounts that can be an issue as well.
 

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I would think a bad/clogged solenoid would cause such a problem. The solenoid on the side (facing the radiator) is what controls the shift pattern, if I am correct. If it is mis-adjusted or even clogged (which has been known to happen) you can experience rough, clunking shifts.
 

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It depends on what you mean by clunking. In your last thread, you mentioned a fluid change. Did you ever do that, and if so, did you retrain the trans as described on the trans fix page on allpar?: http://www.allpar.com/fix/trans.html
Some shifts are going to be rougher than others. For example, if the trans is starting to downshift and you hit the gas, it's not going to be the smoothest shift. The good news is that if you're in tune with your machine, you'll soon learn how to "drive with the transmission" so that it doesn't happen or happens less often. It might take a bit of effort at first, but it quickly becomes subconscious.
 

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A solenoid should not clog up in a healthy transmission. If there's enough garbage to plug the solenoid the transmission won't be long for the world.
 

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Discussion Starter #7
I haven't done anything with the fluid yet, as it looks nice and clean. It could be that I am accelerating just when it wants to downshift, or something like that. Maybe just some more time and getting used to it is in order?

I will be updating the TCM next week.
 

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Again what you describe is not normal. Change the fluid and update the TCM. If it's shifting rough it's probably wearing faster than it should.
 

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At this point getting the fluid and filter done would be my priority. That will make the biggest difference.
 

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Discussion Starter #10
Bear in mind it only does it on occasion, and only at low speeds... like if I'm coasting through town at 25mph and then accelerate again, or something.

All shifts are super smooth at wide open throttle.
 

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I don't know how else to say this again: THAT IS NOT NORMAL. Occasional or not, something needs attention or it will become a worse problem.
 

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Discussion Starter #12
Yes, I understood you the first time. I was just adding as much information as I could about the symptoms at an attempt to be as helpful as possible in my description. I already stated I'd be changing the TCM next week, so we'll see what that does. I'll most likely end up doing the fluid and filter as well.
 

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Discussion Starter #13
To add, (I just went for a drive) it's really more like a mild 'thud,' as opposed to a 'clunk.' Basically it's shifting okay, just mildly harsher than it normally does... so I'm banking on the revised computer making it work better, otherwise I'll get the fluid changed out. I'll update my findings afterward.
 

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Discussion Starter #14
UPDATE

I installed the newest TCM (ending in 6122)... there is a WORLD of difference. This feels like a completely different car. It shifts quite a bit smoother I think, overall. It widened out the gears BIG TIME, and isn't shifting so often. It also downshifts MUCH BETTER and will take off like a scared cat if I punch the accelerator now. I LOVE IT.

Outside of that, it still occasionally gives a very mildly harsh shift. I'm changing the fluid and filter within the next few days and we'll see if fresh ATF+4 helps it any. I figured I may as well do everything I can possibly do to be absolutely sure this transmission has NOTHING to complain about... most likely also adding a transmission cooler as well.
 

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Discussion Starter #15
UPDATE

The trans cooler is now installed, fluid and filter changed. It works great, and I think the occasional mild harsh shifting I'm feeling is probably due to my front motor mount, which is fairly worn. The shift itself feels perfectly smooth, i'm just thinking it's felt a bit more due to that mount being bad and rocking the whole engine, depending.

The cooler installation went fairly smooth after I figured out where I'd attach it. I simply used some long zip ties and zip tied it around the metal frame right behind the grille.
 
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