Failing stall veter or slipping trans?

[BlownEarDrums]

I have a CPT Level 3 4l60e that I purchased used with very low miles on it. It has a Precision Industries 3 disk 2800 RPM Stall. I have put a little over 5000 miles on it and have noticed it is acting up. So I think..........

At any point in driving (hot or cold) if I am cruising and give it more throttle to say pass a car.
I can feel the torque converter unlock, RPM's jump up to about 3000 (the norm) and the car start to accelerate. If I add more throttle wile doing the the RPM's start to climb higher. 4500-5000. If I do this rather quickly sometimes I can fell a very slight shudder, and more power transferred to the wheels until a bump and no greater pull into the seat. When easing into it I can feel the power transfer more slowly but still have odd climbing RPM's

Oddly enough, if I WOT the car from a stop. Tires spin, 1-2 chirps (feels solid), 2-3 is firm, but not quick, nor slow. Feels fine, slightly firmer than stock. From a roll, the car down shifts, firmly grabs the gear and flat out goes. Feels pretty good at all times (%99.5) other than adding more throttle and more throttle, TC unlocked in the middle of a gear. 1st is too short to really notice anything. 2 and 3 both have the slipping/power transfer fail symptom.

I, typically jumping to the worst possible conclusion, feel that the tranny is starting to slip. Anyone have any ideas as to what I could be feeling? Feel free to ask more questions or for me to preform some sort of tests.

Thanks in advance

Brad

[JetJoe]

How long has it been doing this? If the trans is slipping that much, the fluid will start to discolor and smell burnt. What other mods do you have? A larger TB without a PCM program for it will result in low trans line pressure. I am not sure if that would cause the kind of slipping you are discribing, but it has been known to cause trans issues over time.

[BlownEarDrums]

Thanks for the reply. To be honest, the transmission felt funny from day one. I never drove a stalled heads/cam car before. So I let a buddy who has a similar modded f body (heads/cam355/3600stallth350) take the car for a spin and he re assured me that it felt very good and I had nothing to worry about. I have put about 5000 miles on my engine and transmission.

Its been slipping like I have described for about 250-500 miles. (hard to tell because I try not to beat on it). I paid for a mail order tune. I specified all my mods in great detail. I had a rough time with the tuner and I eventually gave up. I told the tuner that I have a BBK 52mm throttle body. Your the second person to ask if its tuned for a TB. Not a good sign.

Looking through the tune and comparing it to a stock tune I have I found that he didn't change anything in the pressure tables expect for this one:

Line Pressure Offset Vs %TPS Vs Gear (Normal Mode)

0 0 0
-3 -6 -8
-3 -8 -11
-6 -11 -14
-4 -10 -14
-2 -8 -13
0 -9 -12
-4 -12 -17
-5 -13 -17
-6 -14 -18
-4 -13 -16
-2 -10 -13
-2 -8 -11
0 -3 -7
-4 -6 -8
-7 -9 -11
-6 -10 -10

I pulled my inline K&N HP-3001 filter and cut it open to check the element. Turns out my friend whom I asked to connect the lines on the transmission messed up. He had the lines backwards and it blew out the filter element. There was a good amount of material inside the filter but I am sure most got past when it blew up. I spent the day yesterday removing the exhaust, cross member and lowering the tranny to get my big ass hands in there to switch the lines. Spun on a new filter and have put about 100 miles on it. Plan is to go to my shop and pull this one , cut it open and drop the pan. Fluid is becoming burnt, its not as pink as the new fluid and has a slight toasty smell. I will change the fluid to day as well.

I greatly appreciate your reply and input. I am going to up all the Main Line Pressures by say %25-%30. And see how it feels.

[BlownEarDrums]

Quick update. I cut open the second HP-3001 Filter and it looked brand new inside. So I dropped the pan, and found some metal shavings in the bottom of the pan, as well as some stuff stuck to the neodymium magnets I put in the pan.

Here are links to the pics. They are super high res so detail can be easily seen.

Here is the blown out filter:


http://i1093.photobucket.com/albums/...l/DSC00570.jpg


Pan dropped:


http://i1093.photobucket.com/albums/...l/DSC00572.jpg


Magnets up close:


http://i1093.photobucket.com/albums/...l/DSC00573.jpg


One of the larger metal shavings. They are ferrous (stick to magnet)


http://i1093.photobucket.com/albums/...l/DSC00574.jpg


Close up of shavings in the pan:


http://i1093.photobucket.com/albums/...l/DSC00575.jpg


Magnets were stuck under this part. Some of it is magnetized and holding particles. Could this be a problem?


http://i1093.photobucket.com/albums/...l/DSC00576.jpg


Wiped the "drip" off the bolt in the above picture:


http://i1093.photobucket.com/albums/...l/DSC00577.jpg


Filter looks brand new:


http://i1093.photobucket.com/albums/...l/DSC00578.jpg

When I started tearing the element out of the blown out filter I found that the media has done a good job and captured a large portion of the black stuff similar to whats on the magnets.

Any one have any ideas where this metal could be coming from? Or some where I can look wile I have the pan off. Everything looks to be in good shape.

Thanks in advance Brad.

[Mr pogo]

the black is clutch wear, lining and steels.
might want to put a test gauge on and see what the pressures are going thru the gears to make sure the bigger tb is programmed in right.
if theres still the slippage feeling then may need to dissasemble more.

[BlownEarDrums]

I did a little research and found that the tuner did almost nothing for the main line pressure tables. I compared a tune found on line with similar spec'd stall and set up and there is a large change compared to mine. Now I'm really pissed at this tuner.

Judging by how much is in the pan of this filter how much life has been lost on this trans mission? There's about 5000 miles on it with these transmission tune values. I will post a pic of the first filter that has 5000 miles on it.

These are the Main line pressure values from the 2 tunes:

My Tune:

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
10 5 0 0 0 0 4 4 4 4 4 4 8 8 8 8 8
15 10 5 4 4 4 4 4 4 4 4 4 8 8 8 8 8
30 25 20 15 15 15 15 15 15 15 15 15 15 15 15 15 15
90 90 27 27 27 27 27 25 23 23 23 23 23 23 23 23 23
90 90 90 35 35 35 35 35 35 34 33 33 33 33 33 33 33
90 90 90 37 37 37 37 37 37 37 37 37 37 37 37 37 37
90 90 90 90 42 42 42 42 42 42 42 42 44 46 46 46 46
90 90 90 90 90 47 47 47 47 47 47 47 47 47 47 47 47
90 90 90 90 90 57 57 57 57 57 57 57 57 57 57 57 55
90 90 90 90 90 68 68 68 68 68 68 68 68 66 64 64 62
90 90 90 90 90 90 78 78 78 78 78 78 76 74 72 70 68
90 90 90 90 90 90 81 81 81 81 81 81 79 77 75 73 71
90 90 90 90 90 90 84 84 84 84 84 84 84 84 84 84 84
90 90 90 90 90 90 84 84 84 84 84 84 84 84 84 84 84
90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90


Tune from the internet:

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
43 43 43 43 43 43 43 43 43 43 43 43 43 43 43 43 43
105 85 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50
105 85 56 56 56 56 56 56 56 56 56 56 56 56 56 56 56
105 85 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62
105 85 67 67 67 67 67 67 67 67 67 67 67 67 67 67 67
105 85 73 73 73 73 73 73 73 73 73 73 73 73 73 73 73
105 85 83 83 83 83 83 83 83 83 83 83 83 83 83 83 83
105 89 89 89 89 89 89 89 89 89 89 89 89 89 89 89 89
105 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96
105 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100
105 102 102 102 102 102 102 102 102 102 102 102 102 102 102 102 102
105 105 105 105 105 105 105 105 105 105 105 105 105 105 105 105 105
105 105 105 105 105 105 105 105 105 105 105 105 105 105 105 105 105
111 111 111 111 111 111 111 111 111 111 111 111 111 111 111 111 111
115 115 115 115 115 115 115 115 115 115 115 115 115 115 115 115 115
115 115 115 115 115 115 115 115 115 115 115 115 115 115 115 115 115

[Mr pogo]

wear or other damage cannot be estimated other than by how it shifts and if there is signs of increased fluid breakdown.
can't help you on the shift tables but like I said throw a gauge on it and see what the pressures are while driving, sherlock has posted pressures I think in the sticky.

[BlownEarDrums]

Thanks for your input Mr pogo. I will check out the line pressures soon. I need to get an extension hose for my gauge. Car is parked for now. Got the daily working again. tranny feels completely different with the new line pressure values tuned in.

[BlownEarDrums]

So I took the car for a spin with the pressure gauge on. I think something is off...

COLD Idle in park-70 psi

COLD Idle in reverse-110-115

COLD part throttle 1->2 and 2-> Shift -125-130psi

COLD cruising adding throttle (where it used to slip)-135-150psi

HOT park-70psi

HOT Roll into 1->2 shift rapid fluctuation between 160-190psi (feels like surging air/liquid in the hose)

HOT WOT from 5mph More fluctuation but in 160-180 range

HOT Part throttle 1->2 shift-145pso

HOT Part throttle 2->3 shif-150 psi

Car is making 350 WHP dynoed before line pressure was changed in the tune. I think that the pressures should be slightly higher. What do the pros have to say?

[BlownEarDrums]

I did some more pressure testing. Adding 1 more qt of ATF seemed to fix the fluctuation problem.

I tried adding more and more pressure to the tune. Each time I added more the tranny felt better. Car pulls much harder throughout the power band.

I cant seem to get over 175 psi at any point. :/ I upped the max main line pressure in the constants table to 135 and took the %100 TPS row up to 130. When I would WOT the car the pressure would drop to 70-75, then spike back up as soon as I let off the throttle. Dropping the %100 TPS row to 125 seemed to fix the problem.

Thoughts anyone?


EDIT: Here is the Main Line Pressure 0-64MPH table if this helps any

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39
105 81 44 44 44 44 44 44 44 44 44 44 44 44 44 44 44
105 81 50 50 50 50 50 50 50 50 50 50 50 50 50 50 50
105 91 66 66 66 66 66 66 66 66 66 66 66 66 66 66 66
105 91 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71
105 91 79 79 79 79 79 79 79 79 79 79 79 79 79 79 79
105 91 89 89 89 89 89 89 89 89 89 89 89 89 89 89 89
105 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95
105 102 102 102 102 102 102 102 102 102 102 102 102 102 102 102 102
106 107 107 107 107 107 107 107 107 107 107 107 107 107 107 107 107
106 108 108 108 108 108 108 108 108 108 108 108 108 108 108 108 108
112 112 112 112 112 112 112 112 112 112 112 112 112 112 112 112 112
116 116 116 116 116 116 116 116 116 116 116 116 116 116 116 116 116
119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119 119
125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125
125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125