Rpm Surge/trans Slip?

[T@urus3.0]

ok, heres another really weird one. got this surge while cruising, rpm's will noticably surge 200-300 on the tach, and i can feel it in the car. not sure if its in the tranny. also, on medium to hard acceleration, she will surge and then smooth out and when it smooths out, its like this sudden burst of power. either something in the tranny is slipping, (bad press solenoid?/clutches?), or maybe a worn timing chain? this is evident in all gears also, and when parked on an incline the tranny grumbles a bit. i got on it from a stop today, and all the shifts were firm and right on, but its like she wasnt pulling as hard as she could(surging)until 4000 rpms. then she wound up quick and painless. it idles like a champ except for a noticable popping sound from the intake and it doesnt seem to be missing. fresh plugs, wires,fuel filter, fuel press regulator and coil pack so who knows. why does my car have the weird problems?

[shoz123]

That is the TC locking and unlocking.

[T@urus3.0]

is that normal?

[shoz123]

Normal for Ford programming. You will notice that if the climate control is in a non-AC state such as floor or vent only that it will not do this.

It takes a chip to program it out. Really dumb idea because it causes excess wear on the TC clutch and heats up the fluid. But maybe that is Ford's plan?????

[sfontain]

Any comments on this? Very similar-sounding thing:

I have an '02 with the Vulcan, 37K. I have been suspicious of my transmission too. I'll explain this scenario as though I'm accelerating gently and steadily because I know the numbers better:

From a dead stop, shift 1-2 at about 15mph. Keep going; shift 2-3 at about 25mph. Once I hit about 33-35mph, I also get a little surge and the tach drops about 200-300 RPM from around 2500RPM. Then usually immediately afterward in the 35-37mph range, I get the final kick down to around 1500 RPM. It's almost like 4 shifts? What is up with that? Which of those final 2 bumps is the TC?

*Edit* This is with a/c off.

[tmonster]

have you tried unhooking the battery for an hour.. I do it overnight. Drive like you want it to be driven and it will adapt to your driving style.....

[sfontain]

Originally posted by tmonster@Apr 11 2005, 07:25 PM
have you tried unhooking the battery for an hour.. I do it overnight. Drive like you want it to be driven and it will adapt to your driving style.....

Geez...another thing I've been wanting to ask.

The car was driven I presume mostly by the same person up until 35K when I got it. So another question is, to what extent is the car unable to adapt? What I mean is, if somebody drives the car from fresh keepalive memory for 35K, then I get in it and drive it for 2000 miles, how different is its current state than it would be if I just started fresh?

I know these kinds of things are a mystery for a lot of people and I've been doing as much research as I can find online, but sometimes it's hard because it's even tough for Ford techs because I just think even Ford doesn't completely disclose that info to them.

[shoz123]

Originally posted by sfontain@Apr 11 2005, 06:20 PM
Any comments on this?* Very similar-sounding thing:

I have an '02 with the Vulcan, 37K.* I have been suspicious of my transmission too.* I'll explain this scenario as though I'm accelerating gently and steadily because I know the numbers better:

From a dead stop, shift 1-2 at about 15mph.* Keep going; shift 2-3 at about 25mph.* Once I hit about 33-35mph, I also get a little surge and the tach drops about 200-300 RPM from around 2500RPM.* Then usually immediately afterward in the 35-37mph range, I get the final kick down to around 1500 RPM.* It's almost like 4 shifts?* What is up with that?* Which of those final 2 bumps is the TC?

*Edit* This is with a/c off.

Yes your car should shift like this. 1st unlocked to 2nd unlocked to 3rd unlocked to 3rd locked to 4th unlocked to 4th locked.

It is hard to feel the 3rd unlocked/locked transition but it can be seen with data monitoring software. It is also rumored that it happens in second also but I have not seen it happen. With the Auto Tap software I can see the amount of slip that is across the TC clutch. When it is locked there is usually 0 to 5 rpm slip.

On the V8 SHO you will feel a real change at WOT when the TC locks up in 3rd which is usually around 80 mph or so.

Ideally when you accelerate, after up shifting or down shifting and after a slight pause you want the TC locked. This also is what gives very little engine braking when you first let up on the gas while cruising. At this time the TC is slipping and will after a while lockup to get real engine braking.

[sfontain]

Originally posted by SHOZ123@Apr 11 2005, 08:03 PM
Yes your car should shift like this. 1st unlocked to 2nd unlocked to 3rd unlocked to 3rd locked to 4th unlocked to 4th locked.

It is hard to feel the 3rd unlocked/locked transition but it can be seen with data monitoring software. It is also rumored that it happens in second also but I have not seen it happen. With the Auto Tap software I can see the amount of slip that is across the TC clutch. When it is locked there is usually 0 to 5 rpm slip.

On the V8 SHO you will feel a real change at WOT when the TC locks up in 3rd which is usually around 80 mph or so.

Ideally when you accelerate, after up shifting or down shifting and after a slight pause you want the TC locked. This also is what gives very little engine braking when you first let up on the gas while cruising. At this time the TC is slipping and will after a while lockup to get real engine braking.

Well holy crap that's it--I had no idea the TC was supposed to lock in third.

So that small bump that drops from about 2500 to 2200, that's the TC locking in 3rd? Or is it the 3locked to 4unlocked shift? Likewise, is the 2200->1500 drop the 3rdlocked->4unlocked or 4unlocked->4locked?

I really appreciate this. This is my first automatic transmission! (*sigh*)

[shoz123]

When the TC locks it will drop the rpm about 300, when it unlocks it will raise the rpm about 300 rpm.