I just bought a 1996 Riviera SC 3.8 with what looks to be a 4t60e. The car has no "take off" power. It goes into gear strong, both forward and reverse, the fluid is kinda brown and slightly burnt, it shifts. The PO thought it was a problem with the supercharger and an exhaust leak. I thought it felt like either the TC isn't locking up or somethings awry with the electrical in the tranny. I have a Techscan 7000, the data stream that seems to be tranny related reads as follows: TCC COMMAND-disen, 1-2 SOL-on, 3-4SOL-on, TCC ENABLE-off . This is running in park, in r, in drive, didn't seem to change. I did not drive it, it'* raining and we have a muddy driveway
I am not familiar with the 4t60e, is it similar to the 4l60e?
Thanks,Sherri

I would think a '96 would have a 4T65E........but if it has a modulator valve, it'* a 4T60E....not even close to a 4L60....one is transverse, the other longitudinal....

Does the exhaust sound loud? If the leak if before the cat, it could make the O2 sensor read lean....why does he think there is a SC'er problem? Noise? No boost?

So you bought this knowing it had a problem?

Condition of the fluid is not a good sign....hope you were prepared for a possible tranny rebuild, before buying the vehicle.....

Are there any engine/tranny codes?

Both solenoids will be "on", in Park, R, N, and D with the car not moving.....

They do not change until the car is in D and is shifting....

1st, on/on

2nd, off/on

3rd off/off

4th on/off

TCC does not come into play on initial shift into D....if it did, it would stall the engine....

You can try to drop the pan, replace the fluid and filter, and hope you don't see any metal or a lot of gasket material.....

But did you ever take it for a test drive, before buying it? Did it shift at all?

Try this....from a dead stop, lay into the accelerator pedal, and see what the vehicle does...if it doesn't shift out of first and tops out at 3K rpms, come to a stop.....now very lightly accelerate from a dead stop....if it slowly builds up speed, and shifts between gears, and slowly gets up to 60mph, you could have a plugged converter.....

He has the SC'd Buick. It came with the 4T60-E-HD. The 65 came out in 97.

Tech II- I knew it had a problem when I got it, it was at scrap price.I have access to a really good U-Pull-It yard I also can rebuild it if needed.
I was wondering if this was a common problem, or something else.
The PO was just trying to find the best case scenario, the exhaust leak IS pre-converter, right at the flange at the manifold under the firewall.
The SC does "rattle" some, out inside the protruding piece, I put the stethoscope on it.
The car does shift, I will be able to get it out of the driveway today, I will try your test, and hook up the scantool and watch the solenoids.
There were MANY codes, many of which PO tried to fix, he put in new plugs, wires, oil change, etc. but never cleared the codes. I cleared them and will see which ones set today.
While looking into my tranny manuals I did see that it should be a 4t65e, I thought I saw a vac mod on it, I will verify today.
Thanks for the reply and I will report todays findings.

Thanks Mike- I didn't see that in my manual. I will count pan bolts today

Okay there is a vac modulator.
test drive: Starting out shift solenoids are as follows, on/on, on/off,off/off. Then it stays off/off no matter what. I had to turn the car off to reset it to on/on, then it does the same thing. I did not feel a shift, it seemed to go from 0 to 70 in one gear. The other readings- TCC Command stayed disen., and TCC Enable stayed off.
Is this from tranny failure or solenoid failure?
The SC Boost solenoid stayed at 100% from idle.
The TCC PWM(%) was 9.0 at start, 100.0 at 70mph.
The scan tool said it was in 3rd gear the entire time.
There are vacuum hoses plugged off here and there, I have to trace them. The vacuum hose to the vac modulator has a check valve near the tranny and it has no vacuum at idle or WOT.
Pretty the state of the tranny fluid is due to driving it in one gear. I will be lucky if there are any clutches left!
Off to look up the vacuum on Alldata.
Thanks again, it'* a beautiful day to bond with this piece of crap!

"Starting out shift solenoids are as follows, on/on, on/off,off/off. Then it stays off/off no matter what."

I doubt it went that way, otherwise it went 1st, to 4th, to 3rd.....should have been on/on, off/on, off/off.....1-2-3...you had no fourth gear......with all the codes set, it'* possible it wasn't commanded.....

Since you have a scan tool, you should have watched the input shaft and output shaft speeds.......when it was in first, output speed should have been approx 1/3 that of input......second 2/3......third 1/1 or almost equal

Pressure control solenoid should not be at 100%.......should be fluctuating much lower, while maintaining transmission slip rpm to less than 25 rpms when applied...

I may have second reversed- off/on- the car didn't actually even shift, the values changed at the speed they were supposed to, the car trudged along without shifting.I tried it several times. If I stopped and let it run, it stayed off/off, even if I put it in Park or reverse. The only way to get back to on/on was to completely shut it down, key off. Then when I restarted it was on/on. Not sure where the input and output shaft speeds are on my tool, it'* a Tech Scan 7000.
The pressure control solenoid did go right to 100% and the slip stayed very close to the engine rpm.
I feel like the PCM isn't controlling it or something.

Not liking your tranny situation.......

Condition of fluid......

no fourth gear command(some codes prohibit fourth gear command)........

Codes?

PCM may be commanding 100% PCS because of slippage.....

Would be interesting to know what the actual gear you are in.....

Like I said, on a normally shifting tranny, the output speed sensor should be 1/3 of the input speed sensor in first.....2/3 in second, 1/1 in 3rd, and in 4th or overdrive, the output should be greater than the input(but you have no fourth gear command)......

While accelerating, the TCC is not engaged, so slippage can be in excess of 100rpm'*.....but when cruising in 3rd(since you have no fourth), and the TCC applied, slippage should be 25 rpm'* or less(as read on a Tech II)......

The codes are- P0753, P0758, P1651, P1652, P1864, and Po756.
I think it'* in 3rd gear, it has a hard time moving, and it tops out at about 70mph without shifting. My scantool reads 3rd gear continually until I turn the car off and restart.
I don't know which values are the input and output shaft speeds.
I don't think the TCC engaged at all.
The fluid is brownish and smells a little burnt.
I am thinking it'* toast, I just don't want to swap a tranny and still have a PCM issue.
Thanks again!