Shifting Hard, whine from under the car?

[silvachris1]

Ok, so for the past couple days, my car has been a little sick. The current problem at hand is described in the title. Lately when I'm driving, the car has been making a loud whine sound coming somewhere from underneath. I suspect the transmission. The whine increases in pitch and volume with more throttle. One person mentioned that my car sounded like it was supercharged. So that describes the sound. It has been shifting extremely hard [automatic] from 1st to 2nd, and from 2nd to Drive. Then the Drive to OverDrive shift is smooth, but it acts like it doesn't want to shift into Overdrive. It takes longer than when it is running normally. I've read about a similar problem in the past. Someone said that it was a Torque Convertor Clutch Apply Vavle leaking. They said when it leaks, the computer throws a code and bumps up the line pressure inside the transmission. The leak inside is the cause of the whine, and the line pressure increase is the cause of the shift firmness changing. Is this accurate? Are there any other possibilities? What should be done to prevent this from happening again? Also, do you think this is the cause of my SES light?

[DrFix2Fly]

Congratulations, you have entered the world of code P1870 or "transmission component slippage." More than likely, you have wear in your valve body at the TCC valve. The fix is to bring it to a good transmission shop and ask them for a Sonnix valve. The whining you hear is your pump in high pressure mode. Once your transmission senses a slip, in your case at the torque converter lock up, it applies full pressure to all shifts which explains your hard shifting. This is a big problem with some 4L60E transmissions. Take care of it quickly before you break your torque converter lugs like I did.

[silvachris1]

Abnormal wear in the valve body at 43K miles? The first time it happened, I had 38K miles on it. Of course, there's the possibility that it's not the original tranny. The car has been wrecked before I got it, and the only filter that I could get to fit it was for a 96 Camaro. My car is a 99.
Anywho, another problem I've had is serious heat coming off of the hump in the middle of the car. Any ideas?

[DrFix2Fly]

Low milage is not a factor. Mine started doing it just after 36K. Heat is a natural effect from running higher pressures. Get to a tranny shop and tell them you have an 1870 problem with hard shift. They will know all about it.

[Ryan W.]

I hear that sound when I give it the throttle...but the car works great!..should I be worried?

[silvachris1]

<blockquote>quote:</font><hr>Originally posted by DrFix2Fly:
Congratulations, you have entered the world of code P1870 or "transmission component slippage." More than likely, you have wear in your valve body at the TCC valve. The fix is to bring it to a good transmission shop and ask them for a Sonnix valve. The whining you hear is your pump in high pressure mode. Once your transmission senses a slip, in your case at the torque converter lock up, it applies full pressure to all shifts which explains your hard shifting. This is a big problem with some 4L60E transmissions. Take care of it quickly before you break your torque converter lugs like I did.<hr></blockquote>

Where is the WEAR most like to have occurred? And how much do the Sonnix kits usually cost? I've been told that a missfire can set off the 1870 code. It's a weird turn of events but here's how it was explained to me:
Computer reads the speed from the transmission output sensor.
When the car missfires and the RPM fluccuates, the computer reads the output speed from the tranny and sees the flucuation, it thinks the tranny is slipping.
Code is thrown, line pressure increases, TCC apply valve leaks, whining sound follows along with the hard shifts.

My uncle told me that he's seen it happen before (Mechanic), and my car was missfiring before it happend. Still though, I should get the transmission checked out.

<blockquote>quote:</font><hr>Originally posted by DrFix2Fly:
Low milage is not a factor. Mine started doing it just after 36K. Heat is a natural effect from running higher pressures. Get to a tranny shop and tell them you have an 1870 problem with hard shift. They will know all about it.<hr></blockquote>

I know that heat is the universtal killer. And I've been considering a transmission cooler for a while, but haven't really looked into it yet. Tell me, do you know of any good deals on one? Is there a kit I should look for? And how much do they usually run?

<blockquote>quote:</font><hr>Originally posted by Ryan W.:
I hear that sound when I give it the throttle...but the car works great!..should I be worried?<hr></blockquote>

You hear a whine from under the car? Or under the hood? I've been hearing what I think is the alternator for as long as I can remember. The alternator can whine with the throttle, but I've heard of peoples power steering pump whining like this too. As long as your tranny is shifting fine and there isn't an SES light, I wouldn't worry too much about it.

Thanks again DrFix.

[DrFix2Fly]

A Sonnax valve installed will cost a couple hundred. The tranny shop has to pull your valve body out (not the tranny), ream the TCC bore, install a steel sleve and new valve assembly. You may also want to ask them about rebuilt valve bodies that already have this mod done to them. If you buy one that doesn't have it, you will have the same problem happen again in 20K miles.

The problem starts with a modulating TCC valve. In other words, it doesn't come fully on, then fully off. It shuttles back and forth in the valve bore. The valve is steel and the bore is aluminum. The .440" valve stays the same size and the bore eventually wears and allows fluid to pass and release the torque converter lock up. That's the slip your tranny senses. For a slight moment until it reestablishes lock up, the engine speed and VSS speed fall out of accepted parameters. Ours is way too sensive. Hot fluid is more likely to pass than cool fluid, which is why this tends to happen after the car heats up. A tranny cooler is a band aid repair. The real repair is the Sonnax valve kit which is a steel sleeve that goes into your valve body and won't wear out like aluminum.

The whirring sound you hear is your pump in high pressure mode. Your computer commands your tranny to use it to prevent future slips. The unfortunate side effect is a hard shift. You will only get a SES light after it has happened twice in two sequential ignition cycles. Your computer will command high pressure the first time and SES light the second.

Find a good tranny shop, walk in and tell them you have a 4L60e with P1870 and you want a Sonnax valve mod. They can turn this around in half a day.