Symptoms of a failing stall converter?

[95ImpySS]

So I spent a HEFTY chunk of change on a used 4l60e. Tranny has some good parts and was built by a decent builder. It's been working well for about 4000 miles. But lately, it has been feeling funny off and on.

When accelerating from a stop easing into the throttle in 2nd and 3rd gear the more throttle I give it the more the RPMs tach up. It has a PI 2800 stall converter in it and when easing into it, the rpms can get up to about 4500 depending on how much I push it. The same goes for if I am cruising down the road and give it some more throttle to pass a car. I can feel the TC unlock, then the RPM's tach up to about 3000 (Which is normal) but if I ease into it more and more the RPM's continue to go up for a short period, then I can feel a slight rumbling (Sometimes) and then feel the car accelerate harder. This slipping/power transfer fail is not common but happens off and on. I can WOT it from a stop, roll etc and %99 of the time it works amazing.

I'm pretty bummed because I could have purchased a LT1 F-body for the cost of this tranny and its acting up :(

Anyone have any input as to what I may be feeling. I understand that its pretty much impossible to make a decision by a text description. I can calrify, answer any questions or preform some tests if any of you guys or gals can throw at me.

As it sits, I plan to cut open the inline 10 micron filter and take a peek to see whats in it. Other than that fluid is full, pink smells great.

Thanks in advance.

Brad

[Mystery Bird]

Do you have a 58 mm TB and was it tuned for it?

[95ImpySS]

Do you have a 58 mm TB and was it tuned for it?

Well, the tuner I used quite pissed me off. I eventually gave up with him. Being that your the second person to ask that this doesn't look good. i checked through the tunes he sent me and it turns out he only touched this one table:

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 ended up cutting open my inline filter yesterday. My buddy messed up connecting the lines to the tranny. The flow was backwards and it blew out the filter element. There was a fair ammount of build up in the filter. I figure most has gone by after the media popped. I spun another one on and have put about 100 miles on it. Going to open it and take a peek later today. Most likely going to drop the pan as well to see what is inside and add some fresh fluid.

I think I will up the main line pressure tables about %25-%30 and see if that helps.

Thanks for your reply!!

Brad

[dawdaw]

Well when my converter took a dump on me it wasn't a obvious fail (i thought it was the trans)... The car kept losing mph at the track, with NO changes being made to the car... Fluid was clean, didn't smell burnt, trans fluid never got over 180*, trans shifted firm bust kept losing mph... Pulled the drain plug off my trans pan and it had small shiny bits of some type of ferrous metal attached to the drain plug. Pulled the whole drivetrain out and started draining the converter and little bits of metal were coming out of it.. going to the track can help big time determining if you have a shit converter.... find out what rpm your going threw the traps at, find out what ratio your trans is, rear end gear, and tire height, and you can enter it into a converter slip calculator and figure out how much it's slipping. Hopefully it isn't your trans, you are trying to push a heavy b body with that thing, if it's in your budget you might want to look into a 4l80 or th400 for the car and ditch that 60e

[95ImpySS]

Thanks for the reply. I am pushing the little 4l60e pretty hard. Car is full weight and the trans is suppose to be built up to 500 or 600 BHP. I really dont know. I have a RMVB TH400 and the parts to make it fit my car, but man I don't know if I could handle less than 12mpg :) This thing is suppose to be my street strip/LTx Shoot out cruiser LOL

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/i428/95ImpySS/Tranny%20fail/th_DSC00570.jpg

http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/DSC00570.jpg


Pan dropped:
http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/th_DSC00572.jpg

http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/DSC00572.jpg


Magnets up close:
http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/th_DSC00573.jpg

http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/DSC00573.jpg


One of the larger metal shavings. They are ferrous (stick to magnet)
http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/th_DSC00574.jpg

http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/DSC00574.jpg


Close up of shavings in the pan:
http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/th_DSC00575.jpg

http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/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/i428/95ImpySS/Tranny%20fail/th_DSC00576.jpg

http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/DSC00576.jpg


Wiped the "drip" off the bolt in the above picture:
http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/th_DSC00577.jpg

http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/DSC00577.jpg


Filter looks brand new:
http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/th_DSC00578.jpg

http://i1093.photobucket.com/albums/i428/95ImpySS/Tranny%20fail/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.

[firebird_1995]

I believe lockup torque converters have a friction surface similar to the clutches in the trans. If they were slipping/worn that would describe what you're feeling in the car and what you're seeing in the filter

[95ImpySS]

From what I have read the lock up clutches are similar. I don't think its a problem with the lock up clutches bucause it feels fine when the TC is locked. Its only when I would gas it after the TC unlocked.

Turns out the "tuner" I paid to tune my car hardly touched the line pressure tables in my tune.:frustrated:

I found a tune on the interwebz that had a similar description to my set up and stole the line pressure values from it. Wrote them into a new tune and took the car for a spin. WOW it feels so much better. The problem seems to be gone. When adding throttle the car pulls now instead of the RPM's taching up. Im very glad its "fixed", its really much better. But I cant stop thinking about how much wear and tear has been added to this transmission from all the previous 5000 miles of "slip". Makes me more upset, you cant trust anyone to provide a quality service these days.

Any way.... Here are the values from the "Tuners" tune and the one I got from the internet. Its almost double (often more than 2x) the values across the board. :doh:

This is the Main Line Pressure 0-64 MPH

The "tuners" 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

The values off the interwebz

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

[sick70malibu]

Glad to hear you were able to find a solution. It is quite disappointing when you pay someone to perform a service such as tuning and they fail to do a quality job.

Sent from my Venom powered ReZound.

[95ImpySS]

Thanks for the reply. Going to hook yup a pressure gauge to make sure the pressures are where they should be then let it eat. Fingers crossed for a long trouble free life :)

FWIW Some good 4l60e info on the Impala Forums.

Here are what some pressures should be.

"65-70psi in P, N, and D at idle while stationary.
150psi in R at idle while stationary.

Floor it from a stoplight and watch the gauge through 1st gear. You should hit at least 200psi (preferably 230psi) at some point in 1st before the 1-2 shift.

From these three checks, I can pretty quickly judge the overall health of any 4L60E."

Sherlock9c1

http://www.impalassforum.com/vBulletin/showpost.php?p=2526849&postcount=2

[95ImpySS]

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

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

[firebird_1995]

Is that a deep pan?

[95ImpySS]

Nope. Its a stock pan. I stuck with the stock pan because A, its cheaper ;) and B its shorter. My exhaust should scrape before the trans pan. What are you thinking sir?

[firebird_1995]

Well I removed a deep pan before (was cracked due to being driven in a lowered car) and noticed that it was missing an o ring in the aluminum extension piece that lengthens the filter pickup tube. I was going to say maybe that could be a reason for the fluctuations in pressure (if it was missing)

The only other thing would be the seal that goes on the filter tube that goes in the trans but I'm sure you've checked that.

[Mystery Bird]

At this point it sounds like you may have a pressure leak internally. When you were checking pressure were you using D or OD each time? There's so many tables for the trans to adjust. I haven't touched them in a while and my brain is a little foggy on them right now.

[95ImpySS]

Hey thanks for the reply's. :)

I double checked the filter seal when I changed the filter. Looked good to me. There are TONS of tranny tables to adjust. Thankfully my car does not have the "performance mode" button, or cruise control. So shift points are easy to adjust. The line pressure seemed strait forward enough. From what I have read on LS1tech, the max psi a stock tranny can make is 175-200psi. I don't know where the guy from the Impala forums got his numbers from. I will check my Camaro FSM tonight. Maybe this tranny didn't get as modded as I was described. LS1 tech also stated that changing the values in the tune can only build as much pressure as the tranny can mechanically do. IE Stiffer spring or addition of washers. Dunno yet. I'm tempted to drop the pan again, but I think I'm going to put a few more miles on it.