2004 MC SS, 108k.
Naturally aspirated.

My transmission has recently been taking longer to shift between gears. It's more pronounced from first to second, but it will do it on the others. If I slowly accelerate out of first, when it goes to shift it just seems like there's a lag, it's kind of hard to describe. Also, when stopped at a light, if I kind of get on it when it first accelerates it will make a clunking noise right when I put the gas down....but if I let it roll away from the line in idle then accelerate, it's fine.

Possibly related, for a while I had leaky transmission cooler lines. The leak seems to have taken care of itself and I never let the fluid level drop below a recommended level. I know I need to change the lines, but for now it's stopped itself and I don't have the time.

I don't understand automatics as well as I do manuals, any thoughts?

 

I would take care of the lines..

Have you checked your cat?

 

Any leak will cause a loss of pressure

Check your fluid

Could also be the pressure control solenoid in the tranny failing

 

Sounds like your transmission fluid got hot. Especially if the cooler lines were broken.

This will cause the solenoids to go bad, as heat is the worst for transmissions.

I would say the solenoids are shot, you can TRY to drop the filter and put some new dexron 6 in there, but I think you are too late. Might need to replace the solenoids.

 

The cooler lines never leaked more than a drop or two after sitting an entire day, but I suppose a leak is a leak.

Replacing cooler lines involves draining all the fluid anyway, correct? So if I do those, I might as well do the filter?

Regarding solenoids, I take it those are not a DIY job?

 

Depends on how DIY you are.

Look around and see if it is something you can accomplish, most likely, no. It's not.

tripleedgeperformance.com has good reads about our tranmissions

 

Chibi, thanks for the site, there's good info on there.

When I read other people's posts, they propose ideas then never seem to come back to them and finish whether something was successful or not.

To that end, is it possible to plug a fresh supply of ATF into the filter then perform a flush whereby you just run the vehicle in idle until your torque converter pushes out new fluid from your fresh supply?

I'll be doing a pan drop (w/ filter) and changing the fittings and hoses on Friday, but as I read more about flushes, it seems like the above would be the best way to do it, if manageable.

If that's not feasible, is it recommended I do another drop and flush in a couple weeks to try to get out some of the remaining 5 qts that resides in the converter and is not accessible during a pan drop?

 

It's not recommended to hook the car up and do a full flush like that, because sometimes that "crud" is actually holding parts together for you.

If you are already slipping, a full flush could make it WORSE. But getting half of the fluid out and replacing does help. As you know, it could only be a temporary fix.

You could definitely do another drop and fill in a couple weeks.

 

Your flush comment seems to make sense. I didn't want to do a forced flush, I suppose I envisioned that the system would just let the new fluid work it's way all the way through.

I've read I'll need around 7 or 8 qts of fluid after the drop. Since I'll be taking off the hoses, will be I be losing what's in the radiator? I guess I don't know if there's a cavity in the radiator for fluid of if there's just a single internal pipe that gets cooled.

Thanks for all the input, I tend to walk my mind through the entire job before I start to think of questions I'll probably have once I start.

 

I don't know if the cooler line will spill coolant or not.

When was the last time you flushed your coolant? It might be a good time to do that, especially with the warmer weather coming up