[cmitchell17]

My shudder is back even though I've had my slip tables and AFM disabled for probably over 20-30k. I first started seeing signs of shudder at I think around 40k and I got the "triple flush" fix that dosen't work. It went away until now at almost 90k but its getting bad now.

The way it has come on from not being noticeable to now very noticeable has me really worried that it damaged the torque converter. I haven't had any luck being out of warranty getting the dealership to perform the proper flush procedure.

I may need to look into a circle d as well, although I still guess I would need to do the flush with the proper machine and the new mobil 1 fluid anyway.

Its funny that they can engineer the fluid and converter clutches to be right on the edge of a "controlled" slip, but then once they start really slipping to where the driver can feel it, then its like they are done and you've had it.

I don't think we have access to enough parameters in HP Tuners to allow full clamp of the TC clutch during part throttle to completely stop this. However, at full throttle the TCC still seems to lockup eventually with no slippage once TCC pressure is high enough.

[Joshinator99]

Originally Posted by cmitchell17

My shudder is back even though I've had my slip tables and AFM disabled for probably over 20-30k. I first started seeing signs of shudder at I think around 40k and I got the "triple flush" fix that dosen't work. It went away until now at almost 90k but its getting bad now.

The way it has come on from not being noticeable to now very noticeable has me really worried that it damaged the torque converter. I haven't had any luck being out of warranty getting the dealership to perform the proper flush procedure.

I may need to look into a circle d as well, although I still guess I would need to do the flush with the proper machine and the new mobil 1 fluid anyway.

Its funny that they can engineer the fluid and converter clutches to be right on the edge of a "controlled" slip, but then once they start really slipping to where the driver can feel it, then its like they are done and you've had it.

I don't think we have access to enough parameters in HP Tuners to allow full clamp of the TC clutch during part throttle to completely stop this. However, at full throttle the TCC still seems to lockup eventually with no slippage once TCC pressure is high enough.

I'd bet money your TC is in rough shape. Tune only really works if you do it well before you experience shudder for the first time. Once you've experienced shudder, it's all downhill from there.

[cmitchell17]

Originally Posted by Joshinator99

I'd bet money your TC is in rough shape. Tune only really works if you do it well before you experience shudder for the first time. Once you've experienced shudder, it's all downhill from there.

I did zero out the slip tables when I first started to notice it, I can't remember how long after the "triple flush" that was when I started to notice the slip come back I don't think it was that long.

I don't think we have a complete understanding of tables we have in hp tuners to "properly" eliminate the shudder with tuning. Just zeroing out the desired slip table I don't think is enough. Given enough clamping pressure the TCC will lock at WOT.

[thegoat]

Get tour fluid changed again. Trucks guys are having success are doing it every 45k. Id say you did good for that mileage.

[Joshinator99]

Originally Posted by cmitchell17

I did zero out the slip tables when I first started to notice it, I can't remember how long after the "triple flush" that was when I started to notice the slip come back I don't think it was that long.

I don't think we have a complete understanding of tables we have in hp tuners to "properly" eliminate the shudder with tuning. Just zeroing out the desired slip table I don't think is enough. Given enough clamping pressure the TCC will lock at WOT.

I think the problem is people zero the tables AFTER experiencing it. By that point it’s too late in my humble opinion. I’m sure there are more knowledgeable people on this board in regards to torque converter function, but I think zeroing those slip tables as soon as you buy the car from new is the key. That’s what I did although I doubt I’m a good test example for you guys, as I only put 2500 miles on a year. lol

[thegoat]

For sure if the converter is cooked it is cooked. Could some old fluid still have stayed in there? I would think you would have to decide if another fluid change is worth a try before a converter swap. Taking the $200 and putting it toward a circleD ain’t a bad thing

[cmitchell17]

Originally Posted by thegoat

For sure if the converter is cooked it is cooked. Could some old fluid still have stayed in there? I would think you would have to decide if another fluid change is worth a try before a converter swap. Taking the $200 and putting it toward a circleD ain’t a bad thing

Yes, an excuse to "waste" money on better "performance" parts like a torque converter is always a good thing haha

I was looking through my TCM tune today trying to figure a way to have the TCM clamp the TC clutch more, and I noticed somehow my TCC apply pressure ramp table got changed probably when comparing Corvette and truck TCM tunes. I changed it back to stock which interestingly calls for pressure at 0 slip RPM error. I am also assuming the pressure values in this table is a pressure/time, either way I don't think it matters and the only thing that does is that an increase in the table value should equate to more pressure. I have messed with this table before in hopes that it would make the TCM lock and bring the TCC slip rpms down to zero faster at WOT, but I found no differences when changing this table and even maxing it out.

Anyway after putting the values back to stock, I can't perceive any slippage. I do feel some very slight weird chutter/misfire type feeling though but I have always felt that after zeroing the desired slip tables. Looking at the log it appears it is ok too as I can see slip in the 100-200 rpm range and watch as I shift into 2nd from 1st at part throttle you can see it go from 200rpm slip down to 0 +/-1.8 rpm. So I would say its ok now.

The TCM is very slow to ramp it in towards 0 rpm slip which is good in my opinion as it gives you a imperceivably "luxury" shift and drivability experience. It is slow to get to zero at WOT too which is a bad thing as you are loosing horsepower at the wheels if the converter won't fully lock until after 2nd gear when it should immediately lock when shifting to 2nd.

The period the TCM allows greater than 50 rpms of slip during WOT and part throttle is pretty significant and sometimes over a second or two, its interesting how the TCM can control this slip but then when it really slips you can feel it, I just haven't been able to capture a log of the real shudder and slip happening I am sure the time history graph looks different than the controlled slip time graph.

[thegoat]

Yeah idk, all I can say the trucks Manual says severe change is at 45k and the fluid and many people are getting slip right there. 42k, 40k, 44k. Coincidence?

I know we have a lighter car but many have more power and sticky tires and lower shift points.(Adds load) Also it takes about a week or so for the new fluid to soak into the clutch material. These trans’ have wide tolerance and variation from unit to unit when new and even more so at current state. I think you gotta try to figure out what will work best for you. You would want a whole fluid exchange with that bds unit with a new converter too yeah?

[OzzieSS]

Originally Posted by aronSlusa

Mine went away after what I think was zeroing out the tables when I had Tedd tune mine a few weeks back.
So nice, and he got rid of an annoying opening and closing of the TC that the previous tuners couldn't seem to get rid of.

How did you go about getting Tedd to tune your transmission?

[FrostySS]

Originally Posted by OzzieSS

How did you go about getting Tedd to tune your transmission?

I think he can do remote tune if you have an unlocked TCM.