Ok I was having trouble with hard up and down shifts on my 99 Park Ave. Had tranny shop scan and it was the pressure solinoid. I watched him replace it, lots of work, it now shifts nice and smooth except when the TC locks up its a hard lock up and when you kick it down its a hard kick down.

The tech drove it with me and said it MAY smooth out some after driving for awhile but it was the nature of the beast. He said its a "firm" lock up shift but its not a problem ??

I mis spoke, it is not hard on the lock up either in or out its hard on the next shift down after the lcok up or I guess you would call it passing gear. Any ideas

Could it possibly be the 3-2 solenoid? just a guess

not sure even what that is. The tech said its not "unnormal" it seems hard to me and doesn't seem like you should be able to hear/feel a shift like this ?? Where is the 2-3 solinoid ?

Again if you are going 60 mph and everything is fine and you lightly sep on the gas you feel the torque convertor kick down, seems normal but then push a little more and it shifts from 4th to 3rd and this is where you feel it.

sorry im an idiot when it comes to transmissions, I was just hoping that someone else would chime in for ya. BTW when the transmission is downshifting from 4 to 3 the 1-2 shift solenoid which is normally open, is deenergized by the pcm. Maybe you have a sticking solenoid, or a torque converter problem. Anyone else??

it looks overfull on fluid, im gonna suck some out tomorrow with my hose

you need to check it while running, in park

I know how to check it and it is overfull a bit on the stick. I dont know if this would cause the firm hard 4 to 3 shift.

Starting from a stop it goes thru all 4 and lock up fine, its when the tc unlocks and you are still in 4th and kick it to 3rd that its hard then when it comes back out its a little hard too ??

well now the tc is shuddering after lockup, i called the shop back and he said sometimes after running with the pressure switch bad for so long it blows a seal in the tc.


I am taking it back Monday for a new TC $ 500.00 more I hope thats the end of the tranny problems

Automatic transmissions are creatures of there own, thas for sure.
The shuddering could be worn lock up clutchs in the TC itself, its happend before, Ive seen it on my own cars.
The problem is it costs so much time to get into the trany to do any work on it.
You may consider a basic rebuild, which should include a new or Reman TC unit, and new electrical.
Its one thing after another, trust me, it migrates in the quickest way.