Possible problem........

[Spike89]

Just was driving home and stopped at a stop light. The light turned green and I eased on the gas like normal and the engine revved for a moment then "shifted" really hard. It's done this a couple of times now. I drive this everyday and never drive the piss out of it. Any ideas?

[FordMan77]

Sounds like the trans may be starting to slip. What year and how many miles on the trans? How's the fluid look? Nice and red or brown/black (wipe the dipstick on a white towel to be sure of the color)? Might be time for a pan drop and fluid/filter change along with a quart of Lucas stop-slip. Would also be a good time to install the Trans-go shift kit to help firm it up and hopefully make it last longer.

[BillBoost37]

I would start by checking upper and lower motor mounts. Then...the fluid etc.

[Spike89]

2007 Pontiac GP 70,900. This only has happened about six times in the last month in varying degrees of harshness. Fluid is really light pink. I'm going to check those mounts this weekend. I don't have the space at the moment to do the filter and fluid change. I might take it in for that. There is a real slow leak that I noticed when I did my last oil change 900 miles ago, coming down from the trans cooler line. The levels seem to be adequate though.

[BillBoost37]

Adequate? somehow that trips my "you found the problem" o meter

[Spike89]

Is this the kit your talking about........

Transgo SK4T65E Shift Kit

or is it this one?.........

4T65E Shift Kit Combo Kit

[Spike89]

Adequate as its not low or high....

[Spike89]

It's dead in the middle of the hash marks of the dipstick.

[BillBoost37]

Either of those kits work. If you don't buy the one with the filter, you'll need a filter.

Our transmissions don't like being near the low end of the operating range on the dipstick.

[Spike89]

So it might just be that leaking line?

[BillBoost37]

Check things out. If it's in the middle.. then I doubt it's that leak.

[Spike89]

I'm at borcherding in mason ohio talking to my buddy Johnny. He says what is common is that a solenoid could be hanging up. He recommended the same as you guys to drop the pan change the filter refill, and cut apart the old filter to make sure there isn't any clutch material in the filter. Then go from there. $800+ for a solenoid switch if that's what it is. But he might do some side work for me. I'm really debating that shift kit if its worth it. The reviews on it are great.

[BillBoost37]

What you are talking about isn't a normal soleniod issue. Common to our transmission is a bad EPC soleniod aka PCS. Basically pressure is controlled electronically. To swap a soleniod, you drain the trans, pull the subframe, lower the drivetrain a little to get the side cover off..then poof, they are right there.

Here's a writeup that goes much further than pulling the side cover, but that shows you the basics of getting to the soleniod.
http://www.grandprixforums.net/how-t...ess-54448.html

[Spike89]

Right I didn't mean to say switch. They are getting me a price. I just don't want it to get worse so we will replace more than what is needed. Changing out the solenoid requires a fill and filter anyway so ill just get it all done at once including the lines. Then go from there. Thanks everyone I just am trying to understand as much as I can with what is going on with it. Seems like I can never have anything nice, I have hail damage now because of those darn ping pong ball sized chunks falling from the sky last week too.

[02NavyBlue]

If any of those things don't work, take a look at this. Bill, you had actually suggested this to me when describing the same symptoms as the OP.

"You may find that revving the* engine up will finally get the car to move and it will BANG into gear. This is because the pump in the transmission is working harder and moving more fluid thus allowing the added fluid to overcome the leak which prevented the clutch from either initially applying or staying applied."
No Forward Cold

[BillBoost37]

Yeah..I may have. Doesn't mean I was right.

[Spike89]

Had to take off to Michigan to get my 101 year old great grandmother because my grandma is dieing. The car didn't miss a beat the whole time. Hopefully it's just a fluke thing. Ill know soon enough I guess.