LS SWAP 4l60e problems

[Crash_OK]

I am working on finishing up my LS swap http://67-72chevytrucks.com/vboard/s...d.php?t=629115. I still have a few items left to complete. I have put over 600 miles on the vehicle with very few issues. However, I do have two transmission (4l60e) related issues I am hoping some of you can help me with. I am not sure the issues are related so I will describe them separately. I don’t know much about this transmission, I purchased off of craigslist from a guy that claimed he only pulled it out to replace it with a 4l80e. I don’t have much in it, and when I pulled the pan everything looked pretty good, so I changed the filter, installed new seals, and bolted it to the L33. Other than the two problems I am about to describe the transmission has been great. Shifts nice and on time doing normal driving and shifts firm and at the right rpm when you get into it.

First problem is around the TCC. It almost seems like it is operating backwards. When I am on the highway at 73 mph (cruise on), the engine is turning ~2390 rpm.. when I hit a hill or add a little load to the engine, the RPM drops to ~2260 and stays in that area until the load drops. I have a Scan Gauge 2 that shows load.. at 70 load (I assume %) is where the trigger point seems to be. To me it appears that the TCC is working backwards. When I am at light loads the TCC is NOT engaged, and when I add load it is. Anyone have any ideas? Have you seen this before? I have not be able to find this problem in any of my research. The one thing I have seen is that engine misfire can cause the TCC lockup to not work. I wonder if there is any chance if that I am have engine misfire at light loads and not at heavier loads. Seems farfetched to me…

Second problem is around shift points when transmission has been on the highway for a couple of hours. I believe it is heat related. I can drive a couple of hours in the cool part of the morning and not see the problem. However in the heat of the day (95F +) it shows up. While I am traveling on the highway the transmission shows no problems other than problem one above. However, once I come down to a stop or really slow speeds the problem appears. The transmission will not shift from 1st to 2nd or 2nd to 3rd with running the rpms up to ~3500 rpm (Don’t know about 3rd to 4th). There does not appear to be any slippage. The truck will push you back in your seat. And when it shifts it shifts like it would at WOT, firm. After driving in the city for a little while the problem disappears. I can also let it set for a little bit and we are back to normal. Thoughts?

I could swap the transmission out if I need to.. but 99% of the time everything seems to be right.

Thanks for your help.

[Hart_Rod]

Mark - the first thing I would check is the TCC wiring. I'm sure you know this, but on the Gen III motors, the TCC wire should be receive 12v when the brakes are off and then a ground signal when the brakes are pushed. Do you have HPTuners? If so, you can actually set the scanner up to data log when the torque converter is locked or unlocked.

As far as the second problem, that could be an issue with the Force Motor. Actually the more I think about it, they both could be caused by a problem with this. Here's a few threads I found on HPTuners forum:

http://www.hptuners.com/forum/showth...-Highway-Speed

http://www.hptuners.com/forum/showth...ht=force+motor

http://www.hptuners.com/forum/search...earchid=814209

Let me know if any of this helps.

[BR3W CITY]

This is the first discussion of the force motor control that I've ever seen on here....congrats Hart

To tell the truth, I don't understand the thing. Its controllable with a setting % for pressure, but its pressure is independant from the actuall line pressure in the trans...

[Hart_Rod]

Originally Posted by BR3W CITY

This is the first discussion of the force motor control that I've ever seen on here....congrats Hart

To tell the truth, I don't understand the thing. Its controllable with a setting % for pressure, but its pressure is independant from the actuall line pressure in the trans...

, I don't say those words often.....Here's something I found online that gives a pretty good description of it and the 4L60e:

http://jd.offroadtb.com/trans-docs/4...c-controls.pdf

[boostedc10]

I would go with Hart's first post and log some data. Without any data we can only speculate what could be going on. In Hart's second link from HP Tuners you need to at least log the current gear, force motor current , tcc mode and tcc slip. These PID'S with the standard engine PID'S should give you a good idea what is going on.

I also like to run a manual gauge to see what the actual pressure is doing when the problem occurs.

The pressure control solenoid does just that, controls the pressure in the trans for shift quality wear and acts like an electronic version of a kickdown cable.

[boostedc10]

Br3w the force motor table vs temp tables are current applied not pressure. 0 current is full pressure. Normally you wouldn't even touch this table.

The only time I have ever seen it touched is when someone plays with the Allen in the back of the PCS which bumps the max line pressure value and throws off the stock calibration.

[BR3W CITY]

Originally Posted by boostedc10

Br3w the force motor table vs temp tables are current applied not pressure. 0 current is full pressure. Normally you wouldn't even touch this table.

The only time I have ever seen it touched is when someone plays with the Allen in the back of the PCS which bumps the max line pressure value and throws off the stock calibration.

So OFF is full pressure? I've never messed with the setting either, I've only heard it mentioned in discussion a few times...most of which gave up before going far enough to actually sort out the issue.

Does kinda make me wonder if anything was done to mine when I had it built...I still have a random "hiccup" when going into lockup.

[boostedc10]

Originally Posted by BR3W CITY

So OFF is full pressure? I've never messed with the setting either, I've only heard it mentioned in discussion a few times...most of which gave up before going far enough to actually sort out the issue.

Does kinda make me wonder if anything was done to mine when I had it built...I still have a random "hiccup" when going into lockup.

Yes 0 current is full line pressure.

Most normal trans shops won't mess with the PCS. The guys that do are mostly racers building their own.

What is your truck doing when going into lockup?

[BR3W CITY]

Originally Posted by boostedc10

Yes 0 current is full line pressure.

Most normal trans shops won't mess with the PCS. The guys that do are mostly racers building their own.

What is your truck doing when going into lockup?

I had the trans setup by a local rebuilder who has done trans for a few local racers, but they aren't by any means a big name (nor do I know how much I Trust em anymore, but thats another story).

My only hiccup is going into o/d, where it shifts, then feels like it lets-off for a second, before resuming and locking up. Imagine you lock up, but then pull ur foot out so it unlocks, and then resume, so it re-locks...follow? Like it second guesses you on going into lockup, but then realizes its fine.

We've logged a bunch of stuff and couldn't find a tuning reason why it did what it did.

[Hart_Rod]

Originally Posted by BR3W CITY

I had the trans setup by a local rebuilder who has done trans for a few local racers, but they aren't by any means a big name (nor do I know how much I Trust em anymore, but thats another story).

My only hiccup is going into o/d, where it shifts, then feels like it lets-off for a second, before resuming and locking up. Imagine you lock up, but then pull ur foot out so it unlocks, and then resume, so it re-locks...follow? Like it second guesses you on going into lockup, but then realizes its fine.

We've logged a bunch of stuff and couldn't find a tuning reason why it did what it did.

Do you have torque management enabled?

[BR3W CITY]

Nope, everything was pretty systematically disabled or "removed".

[boostedc10]

Br3w do you have a log when it happens? Also what PID's are you logging for the trans?

[Crash_OK]

Originally Posted by Hart_Rod

Mark - the first thing I would check is the TCC wiring. I'm sure you know this, but on the Gen III motors, the TCC wire should be receive 12v when the brakes are off and then a ground signal when the brakes are pushed. Do you have HPTuners? If so, you can actually set the scanner up to data log when the torque converter is locked or unlocked.

As far as the second problem, that could be an issue with the Force Motor. Actually the more I think about it, they both could be caused by a problem with this. Here's a few threads I found on HPTuners forum:

http://www.hptuners.com/forum/showth...-Highway-Speed

http://www.hptuners.com/forum/showth...ht=force+motor

http://www.hptuners.com/forum/search...earchid=814209

Let me know if any of this helps.

Rob,

Thanks for your help.. The brake switch wiring is fine.. the links you sent me were very interesting. I don't have hptuners, but I am now wondering if I should?

After reading about the force motor I am not sure it is the problem. I am wondering if the TCC lockup problem could be related to TCC apply valve? I found this on ebay.. http://www.ebay.com/itm/4L60E-4L65E-...b07008&vxp=mtr but I think there are more complete kits available.

As for the high shift points after the transmission has been hot for a couple of hours, I am not sure yet.

I need to get to tools to look at the PID's as suggest by boostedc10...

I have another 4l60e in the shop I was going to rebuild someday, so I might pull the valve body out of it and swap to see if it makes a difference.

Thanks...

[BR3W CITY]

Originally Posted by boostedc10

Br3w do you have a log when it happens? Also what PID's are you logging for the trans?

We have previously, tho I don't have it in front of me. It feels almost like lifting during the shift, but TPS never indicated that. I'll try to get one of my tunes posted up on here. It wouldn't be bad to have eyes on it....and yall can be amazed at the wonderful smoothness of my graph

The only little hiccup would be that we are using an unreleased version of HP Tuners, I haven't tried opening my tune or logfiles on an older version yet, as there are some parameters that don't exist in the older systems.

[clinebarger]

The EPC Solenoid Does control Line Pressure through the Torque Signal Circuit that runs to the Boost Valve. In a twist the EPC gets its oil from the Actuator Feed Limit (AFL) Valve, The AFL gets its oil from Main Line pressure.

The AFL valve also feeds Both Shift Solenoids, 3-2 down shift, & TCC PWM solenoid NOT directly by the EPC.

The EPC does wear, But usually in the first 20,000 miles then levels off after that. EPC solenoids have been known to last a million miles & more.

The AFL valve & TCC PWM Isolator/TCC actuator valve assembly is BAD to wear the valve body.

[BR3W CITY]

Cline, I know my stuff...and even to me that sounds like latin

Can you clarify a little bit? Not sure how to use the info you put up.

[boostedc10]

What he is referring to is the problem the 4l60e has with the AFL valve bore. What can happen in layman's terms is the bore of the AFL wears out causing an internal leak / loss of pressure. With this internal leak the EPC cannot create the pressure needed (because it is fed by the AFL valve) to move the boost valve, which in turn causes low line pressure all around.

Typically though when this is the case you will have faults for the shift solenoids at minimum (but not always if the bleed off is low).

[psiconversion]

What is the actual application? Are you using a two position TCC switch/brake switch. If not this could cause the sensation you are describing with the torque converter as well

[clinebarger]

Originally Posted by BR3W CITY

Cline, I know my stuff...and even to me that sounds like latin

Can you clarify a little bit? Not sure how to use the info you put up.

Sorry about that, I know you have been battling this for quite some time.
Boostedc10 did a great job explaining!!

A worn AFL bore does not always set Solenoid Performance codes or TCC performance codes such as p1870.

You may want to install a pressure gauge on the trans & Closely monitor line pressure....While monitoring Current applied to the EPC, This can be done through a Scan tool if it shows the Current in Amps. I use a DVOM hooked directly to the 2 EPC control circuits. Use the chart below as reference.

I had a '04 2500HD with a 4L80E that I thought was slipping the TCC upon initial apply, It turned out it was falling out of 4th into 3rd then back to 4th. The O/D clutches were distressed & the AFL valve bore was worn. Reconditioning the valve body with a Sonnax Sure Cure kit & new clutches Fixed it.

[BR3W CITY]

Thanks man, that makes sense. I'm not sure how it would be worn out internally as I had it fully redone when I did the engine...but like I said, who knows if that stuff was ACTUALLY replaced.

I think I can monitor the EPC within HP tuners if a scan tool can, I'll find the PID for it and see if it can be logged.

Thanks again. season is coming to a close here in WI already, so fall projects are coming up.

[Crash_OK]

Update

I believe I have the transmission issue resolved. I installed a rebuilt valve body and the TCC lockup issue was resolved. In addition the transmission ran much cooler after the valve body was installed. I went ahead and installed the transmission cooler as well. My transmission temperature runs about 170F going down the highway and 185F or so in stop and go traffic. This is with an ambient temperature of 93F. We had some cooler weather here this past weekend, 70F and the transmission temperature ran about 155 on the highway and 175 in stop and go traffic. The lockup works great, I set the cruise on 75mph and watched the tach, and it read 2330rpm and never drifted more than 15-20rpm even on the hills.

I just hope I have not damaged the transmission, because I am sure I have heated the transmission up to the point that it did not want to shift. Not sure if it was in limp mode, or that the heat caused something to expand to the point it would not shift. I drove the LC from the lake to home Sunday afternoon, 190 miles, it ran great and the transmission shifted prefect. I did check the mileage and it went from 15mpg to 18.5mpg. That was driving 75mph for about 165miles and the rest was in town driving.

Old valve body




Found the 1-2 shift check ball stuck in the separator plate.







New valve body..



Installing new separator plate and gaskets.



Installed the valve body, filled with fluid and drove… very happy

[BR3W CITY]

So was the cause just the improperly made gasket?

[clinebarger]

Originally Posted by BR3W CITY

So was the cause just the improperly made gasket?

The Checkball being stuck would have caused a slow 2-4 band release during a 2-1 downshift, That's about it.

The PWM isolator valve bore was most likely worn.

With a worn VB & a Stuck checkball, That trans has some miles on it, 185 degrees didn't hurt it though.

[Crash_OK]

Originally Posted by clinebarger

The Checkball being stuck would have caused a slow 2-4 band release during a 2-1 downshift, That's about it.

The PWM isolator valve bore was most likely worn.

With a worn VB & a Stuck checkball, That trans has some miles on it, 185 degrees didn't hurt it though.

Thanks Clinebarger.. I believe the temp got much worse than 185F before I installed the valve body. I didn't have a way to monitor the trans temp until just recently. I have seen 226F before the valve body swap, and I fear that it got higher than that...

[clinebarger]

Originally Posted by Crash_OK

Thanks Clinebarger.. I believe the temp got much worse than 185F before I installed the valve body. I didn't have a way to monitor the trans temp until just recently. I have seen 226F before the valve body swap, and I fear that it got higher than that...

If it's shifting good, Don't lose any sleep over it. The ATF took a hit more than the Trans.

What ATF are you running?