Tcc Problems

Today i started having issues with what i believe to be the TCC. Going uphill with the TC locked the riv will jerk and rpms shoot up +200 then come back down multiple times. It also does it on flat land while cruising but not as much. Shifted into 3rd and same issue so im pretty sure im not losing OD and the trans does not slip and is just fine under WOT. When the TC locks up it is a very harsh shift/transition especially going uphill. I can also tap the brake and the TC will unlock, i have no dtc's, fluid is not burnt. The trans is a used unit i have no knowledge of the actual mileage, filter and fluid change was done when i swapped the trans Nov 2011 about 43K miles ago.

If the fluid fill was new dex 3 your fluid may have gone south some time ago although it did not smell burnt per se. GM stopped policing the dex 3 standard a while back and so most of the dex 3 compatible fluids that I know of are junk.

That said, I think ur tcc may be shot.

Don't feel bad I rebuilt my trans last year because I think the dex 3 wore out and I did not realize.

Oh by the way once you switch to dex 6 NeVeR switch back. Never ever.

Your TCC solenoid might be acting up, or failing. Or, some debris may have gotten by the filter and into the TCC circuit in the valve body. If nothing else is slipping, feels strange, or is fine in 1st, 2nd, and WOT, its more than likely one of those scenarios. If it gets bad enough, your SES light will turn on, and the PCM will command converter lock-up (which makes it suck major ass to drive).
If you have a good scanner available, you can try commanding the solenoid on/off a bunch of times. This might dislodge any debris temporarily, or permanently if you're lucky, and if that's even the problem.

During my drive home from work i did everything i could to get it to throw a code, i may have to borrow a scanner and try to cycle the solenoid. Would kicking it in and out of lock up while driving accomplish the same affect? I realize to replace it id have to drop the subframe to access the side of the trans anybody have a diagram showing which solenoid is which and the valve body circuits.

I had the same problem you're experiencing about 2 years ago, when my car had 200k miles. This was 50k after a transmission rebuild. Based on how mine started failing, I feel it was actually the TCC lining wearing out, permitting slip. The PCM senses the slip, and so disengages the clutch to protect the unit from heat and further wear. Mine started after I pulled a trailer in OD, and eventually got progressively worse until it was slipping when any load was applied.

Instead of pulling the trans and replacing the TC clutch, I opted to turn off the TCC lock-up command using a PCM tuner. This results in a less efficient MPG, and the need for a trans cooler ($120), but overall I like this modification because it makes the car's throttle more responsive in 3rd and 4th gear. Highway MPG drops to 24-26 MPG, city stays the same. I average 20 MPG. Car is way more responsive without TCC on the highway. City driving is the same.

I've put over 60k miles on the car since the tune. You can read more about it here:
https://rivperformance.editboard.com/t8717-write-up-tuning-trick-for-failing-torque-converter-clutch-tcc-lock-up

I read your post before I started this one. I usually research the forum before asking any questions and wasting peoples time. I don't have access to a tuner so I can't really go that route and the Riviera is my commuter for work. How time consuming is replacing the converter clutch?

SuperRivL67 wrote:

I read your post before I started this one. I usually research the forum before asking any questions and wasting peoples time. I don't have access to a tuner so I can't really go that route and the Riviera is my commuter for work. How time consuming is replacing the converter clutch?

Remove the entire transmission.....no easy way out of that one.
BTW, tuning out your TCC is not recommended. A trans cooler WILL be needed as you WILL overheat your transmission without it. Tuning out the TCC is a Band-Aid fix, not a repair

EDIT: A trans cooler (if you choose to turn off TCC) would save the rest of the transmission, but cannot prevent the torque converter from overheating.

AA, will you eventually replace the TC clutch, or are you just gonna ride it out like you have it now?

I have no problem dropping the whole trans that's only a couple hours of work. Is the clutch part of the Tc or is it inside of the trans with all the other clutches? I have the next three days off so its either fix this trans or gamble on a used unit I find at PickNPull if I can find a riv or PA

The clutch is part of the converter itself. The entire thing must be replaced.
If it's surging, not slipping, it's very doubtful that the converter is bad. I'll almost guarantee it's a solenoid or valve body problem...which just requires side cover removal.

See, the converter is engaged, or it isn't. The only time it actually allows slip is after you've been cruising at a steady speed for a bit. The PCM allows it to slip to find a nice balance between heat, and efficiency. Surging or "searching" is usually caused by improper pressure and control.

It's surging, now I've also noticed a whine from the trans once I've driven for awhile I can barely hear it over the sc. The fluid is not low

Hmmm. Ok.

Is the trans shifting harder than usual? Generally, the PCM will set a P1811 code without an SES light when it senses slipping. It will then command max line pressure, which is where the whine you're hearing is probably coming from.

IIRC the zzp pcm adds line pressure and I also have the b&m electronic shift kit so the trans shifts very well and doesn't slip I was just concerned with the whine because the trans that the car came with (fried) had the same whine.

ZZP, B&M, doesn't matter. The PCM will see TCC slipping and command it anyway. You may not notice it because you've got the pressures hiked up enough to mask it. Take a drive to Autozone or something and see if they pull up a P1811 in the trans.

I can't hear the whine, so I'm just trying to help out with your descriptions. If the trans whines when you first start the car, and is loud, then I'd be worried. But a faint whine after you've been driving, and the TCC is slipping, is more than likely just a symptom of the slippage.

It's up to you I suppose. Drop the cradle and take off the side cover, replace 2 $30 solenoids and see if it works...or take the entire trans out. I think I'd try the solenoids first.

I data logged it and scsned for any type of codes Omw to work which is about 75 Mike's through hills and steep grades and had no codes. The whines not loud when I first start the car.

Well, who knows what ZZP actually tuned. They may have deleted the P1811 code.

I would pull the pan, and look for crap. Any abnormal buildups in clutch material or pieces would point you in the direction of a hard failure. If it's all clean and looks ok, pull the side cover, and pull the solenoids. Check the valves behind the solenoids. If they all move freely, slap 2 solenoids in it and see. If you want to be "safe", throw a valve body on it while you're in there. It's almost impossible to diagnose the exact problem without dismantling the entire transmission.

Again, with the symptoms you're describing, it sounds like a solenoid or fluid channel failure.
Only about 30% of the transmissions we repair here, with your symptoms, actually need a valve body. The rest are solenoid failures....

Ok then ill knock those out either today or tomorrow and go from there. I'll update with the outcome. Is there a gasket kit for the pulling the side cover

The side cover gasket is re-useable. It's rubber with a metal base. Just inspect it and make sure none of the rubber is separated from the metal, and you can re-use it.

If/when you pull the cover off, take the T40's (4 of them) on the bottom of the cover out FIRST, and install them LAST. Not practicing this may result in a cracked side cover. Also note the locations of the 13mm studs you pull out as well. All the rest are 10mm.
Look in the Write-up section....awhile back I did a write-up on replacing the TCC solenoid.

charlieRobinson wrote:

AA, will you eventually replace the TC clutch, or are you just gonna ride it out like you have it now?

I looked into it, and decided I won't be pulling the trans just to replace the TCC. Last summer when the engine came out for rebuild, the transmission was right there to access, but I opted not. I know it might seem like a band-aid fix, and it did start out that way, but after deactivating TCC and driving 50k miles, I found something I never realized before: Rivieras have usable 3rd and 4th gears. These gears are a shorter ratio than what we experience when driving around with TCC lock-up. The lock-up creates a 1:1 ratio to the output, so the effect is like an extra gear being added on. You start in 1st, then 2nd, 3rd + TCC, then 4th + TCC (OD). When you are really on the gas, you enjoy some of 3rd, but almost never get to run in true 4th gear.

Why does that matter? With a little shift tuning, the result of disabling TCC lock-up is near instant throttle response on the freeway or on country roads. With just a litte bit of pedal, the car will lunge forward without the need to downshift. It feels like running a hotter spark table. It's like driving in 3rd lock-out on the highway at 70mph, except the RPMs aren't as high, and without the extra noise (4th gear is a very nice cruising gear without TCC lock-up).

The OEM method of pushing the gas half way to wait for TCC to unlock, and then a little more until the downshift comes - that might work for some, but it is really is not a responsive or sport-driven way to drive. The supercharger adds needed torque to push the car, but there's the lag that comes with pushing the pedal and waiting for something to happen. Then when the power comes on, the downshift is very abrupt. It's very similar to turbo lag. The difference with our cars is, you can overrule the lag by pushing the pedal even further. That sudden burst of torque when 3rd gear arrives makes people smile, but in a hard high speed turn, you don't want that kind of uncontrollable power. Rather, a smooth delivery from feathering the gas is what I like. Much easier to control the front wheels. Much more like driving a manual transmission.

Another benefit of deactivating TCC lock-up is less KR. TCC puts a lot of load on the engine, which demands boost even at low RPM. When you're driving up a hill in cruise control and the engine starts lugging, that's because it's demanding most of the engine's torque to drive the 1:1 lock-up and 4th gear OD. This is a condition for KR. If you drive up the same hill with TCC off, there is less load to the engine because it is spinning faster. In short, trading torque for RPM. The point is, you go up the hill at the same speed, but without the spark knock. This goes for any driving where high loads are encountered at low RPM.

Like Scott says, you MUST add a trans cooler, and it helps to monitor trans temp in-car. One thing I know: my trans got MUCH hotter (220ºF) using TCC lock-up without a cooler than it does now without TCC lock-up and adding a cooler (rarely above 185ºF). With 60k miles under it's belt, including several 500-1000 mile trips, racing evens, and daily driving, I would trust my current non-TCC transmission over any OEM one. We all know the transmissions in these cars are the weak link. IMO, disabling TCC lock-up is an improvement, not a bad-aid. As with anything, it must be done correctly to be reliable. It's not a fix everyone can do, and most transmission techs wouldn't think of it. But to be fair, most people don't think a Riviera can be driven the way ours are, so your typical approach to repair often doesn't provide the best result in my experience.

Bad news, had to work half a day today because all the other crafts are off, went to leave work at trans won't even shift out of first and slips in first. When I check the fluid last night it was over filled I drained about a good two quarts out of it. Ive got Napa bringing me a case of atf I'm going to add some and see if I can just make home. That whine is very loud now

Aaron,
Our cars have a relatively loose torque converter to get the revs up quickly. I've always noticed that on really cold mornings when the PCM delays lock up until the fluid temperature comes up. There is a fair amount of slip from the higher stall speed. That of course adds to performance, but heats up the fluid, and takes a toll on the efficiency. The more torque applied to a converter, the higher it will stall.

SuperRivL67 wrote:

Bad news, had to work half a day today because all the other crafts are off, went to leave work at trans won't even shift out of first and slips in first. When I check the fluid last night it was over filled I drained about a good two quarts out of it. Ive got Napa bringing me a case of atf I'm going to add some and see if I can just make home. That whine is very loud now

Well now that opens up a whole new can of SURPRISE!!
This may be a dumb question, but did you check the fluid level while it was running? If not, it will show over-filled.
Still get it home, and pull the pan. Your filter may be clogged to all hell at this point. The type of debris in the pan/filter should help point you in the right direction. Break the filter open and have a look....

I feel your pain. I literally just went through this a week and 1/2 ago. Had to rebuild the trans. The input seal took a poo, then the forward band broke. Fun times. Hopefully yours is something easy

Abaddon, you say in your sig your TCC is modified. Did I miss this somewhere or what does that mean/what did you do?

I'm sure the trans or tc is toast, it probably got too hot on the way to work. I could smell it a couple times coming down the hills. If I let it and cool sit it'll go into gear and move for a short distance then it will start to whine and not engage at all like im In neutral. So all I can do now is sit and brainstorm while I wait for the tow truck.

God bless ya and I hope ya get her back on the road soon!