2007 4l80-E TCC slip FIXED

Post Reply
rc195840
Posts: 12
Joined: Thu Oct 31, 2013 3:08 pm
First Name: RC
Last Name: Carter
Other:

2007 4l80-E TCC slip FIXED

Post by rc195840 » Fri Aug 07, 2015 3:55 pm

2007 Chevrolet K3500 service truck with 6.0 gas engine and 4l80-E transmission. Customer came in saying transmission was slipping and trans temp was going very high then shifting hard. Codes were PO218 trans overtemp, PO741 TCC performance or stuck off and PO894 trans component slipping. Cleared codes and on road test transmission shifted fine but had over 350 rpms of TCC slip when commanded on. Pulled pan and it was clean. Think customer changed fluid before he came in. When cooler was checked it was almost completely clogged with TCC clutch debris. Sold overhaul with new radiator and new cooler. Trans was in very good shape on teardown. All hard parts in very good shape and no clutches burnt. Installed kit, new converter, VBX valve body. Valve body came with new EPC solenoid, shift solenoids, PSM, updated TCC regulator/actuator limit valves. Installed new pump body bushing, new stator bushings with Sonnax wider stator bushing. Also installed new Sonnax line to lube regulator valve and Sonnax progressive line rise boost valve and sleeve. On road test after overhaul trans shifts fine but still have TCC slip. No change at all from when it came in. Scanner says pcm is commanding it on and duty cycle ramps up but still no rpm drop at all. Removed pan to check TCC apply valve in pump and could not get end plug out to check it. Pulled trans to check pump and turbine rings. No damage to rings and all valves in the pump are free. The end plug was hanging on the snap ring groove. It was a little loose in the bore but could not get it out past the snap ring groove without pushing on the valve to remove. Removed the PWM solenoid and stroked the regulator valve and its free. What am I missing ? Trans set no codes on short road test did not want to damage new converter but its still slipping over 300 rpms when TCC is commanded on. Any suggestions on what to check while trans is out ?

Thanks R.C.
Last edited by rc195840 on Sat Aug 15, 2015 11:55 am, edited 1 time in total.

User avatar
tranibob
Posts: 2093
Joined: Thu Oct 31, 2013 3:15 pm
First Name: Robert
Last Name: Moreau
Other:
Location: Laguna Beach, CA
Contact:

Re: 2007 4l80-E TCC slip

Post by tranibob » Fri Aug 07, 2015 4:05 pm

It sounds to me like you have covered pretty much everything internally.

Does it feel like the lock-up apply at all, or does it just remains wide open when the computer ramps up the duty cycle %? It almost sounds like the computer is defective and not doing what it thinks it is doing.
Robert Moreau
Technical Support Representative
Sonnax Industries, Inc.
Laguna Beach, CA 92651
rmm@sonnax.com

Keep Up with Sonnax via E-mail, Facebook, RSS & More! Become a Sonnax Insider

rc195840
Posts: 12
Joined: Thu Oct 31, 2013 3:08 pm
First Name: RC
Last Name: Carter
Other:

Re: 2007 4l80-E TCC slip

Post by rc195840 » Fri Aug 07, 2015 5:11 pm

Bob I am starting to think that its not working at all. I guess what threw me was the clogged cooler system when it came in. There was no clutch damage in the unit on teardown but the cooler was almost plugged up completely. When I went to blow the old fluid out of the lines before hooking up the flusher it was very hard to blow through and I got a jug full of TCC clutch that looked like coffee grounds. Radiator and cooler were replaced at time of overhaul because I did not want to take a chance on the cooler system with it being so much junk in it. It reminded me of the Chryslers we see so much of. It had to come from the converter because there were no clutches burnt in the transmission. I pulled the pan this morning to stroke TCC apply valve in the pump and when I couldn't get the end plug out I decided to just pull the unit to check the valves and orifices in the pump thinking I must have missed something or damaged a turbine ring on assembly but nothing was found. Now I feel pretty silly not putting the shifter box on it before pulling it back out. I only see a handful of these units a year and to be honest with you I had a 4l60-E give me a fit with crazy TCC slip a while back that I posted on here and it turned out to be a piece of junk stuck in the orifice in the pump. Yea I broke the golden rule and pulled this thing back out before I properly tested it. I am going to reassemble it and put it back in Monday so I can properly test this thing. I just wanted to bounce it off the forum to see if I was missing something. Cant think of anything else to check for while I have it out. With the overtemp code it came in with and the fluid looking to good for the mileage 115k I don't know how hot this thing has been. Like I said its a service truck loaded heavy all the time. I opened the original filter up and there was only a very small amount of that TCC debris trapped in the filter but the cooler was clogged with a lot of it.

Thanks R.C.

zzyzxpat
Posts: 386
Joined: Thu Oct 31, 2013 3:17 pm
Other:

Re: 2007 4l80-E TCC slip

Post by zzyzxpat » Fri Aug 07, 2015 5:14 pm

Make sure that the return oil going into the rear cooer line is actually circulating, spun bushing, blocked center support, etc.
Pat Schulte
AAMCO Transmisssions
Temecula, Ca.

User avatar
tranibob
Posts: 2093
Joined: Thu Oct 31, 2013 3:15 pm
First Name: Robert
Last Name: Moreau
Other:
Location: Laguna Beach, CA
Contact:

Re: 2007 4l80-E TCC slip

Post by tranibob » Fri Aug 07, 2015 5:17 pm

It is a strange one for sure, it was trying to apply at one point for sure before you got it since the TCC lining was in the pan. If it is not applying at all then I wonder if maybe you just got a case of bad luck here and ended up with a defective converter? Too late to tell once it is out of course, but have all pulled transmissions out too quickly, no point beating ourselves up when it happens, it will always happen unfortunately no matter how much we think we have learn out lesson. Don't ask me how I know ;-)
Robert Moreau
Technical Support Representative
Sonnax Industries, Inc.
Laguna Beach, CA 92651
rmm@sonnax.com

Keep Up with Sonnax via E-mail, Facebook, RSS & More! Become a Sonnax Insider

rc195840
Posts: 12
Joined: Thu Oct 31, 2013 3:08 pm
First Name: RC
Last Name: Carter
Other:

Re: 2007 4l80-E TCC slip

Post by rc195840 » Wed Aug 12, 2015 8:40 pm

4L80-E TCC slip fixed. The problem was in the TCC shift valve bore in the stator. With the pump not bolted together the valve moved freely and returned with spring pressure as it should. With the pump bolted together and torqued to 18 ft. lbs. the valve would move about 1/8 inch and then bind. Unbolt the pump halves and valve would return on its own. With a straight edge across the stator no warp could be seen. After installing a new pump transmission works as it should and no TCC slip. Got to talk to the driver when he came by to pick up the truck and he tells me that the trans had been shifting hard and overheating for over a month and his boss, my customer, tells him to just keep driving the thing. Driver says the thing had been pegging the trans temp gauge at 300 for over a month. This whole thing started with a worn TCC regulator bore in the valve body that could have most likely have been repaired without overhaul if it would have been brought in for a diagnostic when it first happened. Been in this game along time and am always learning new lessons that hopefully makes me a better builder but the human factor involved in these failures boggles my mind more than anything. Anyway guys thanks for the replies it really helped me figure this one out. Lessons learned!!!

R.C.

xtr366
Posts: 52
Joined: Thu Dec 24, 2015 3:58 pm
First Name: tony
Last Name: nicoletti
Other:

Re: 2007 4l80-E TCC slip FIXED

Post by xtr366 » Wed May 06, 2020 11:32 pm

I know this is an old post but we just got the same issue that came in from another local shop. They changed everything but do not recall the stator valve.

We will try that first. Do you have any suggestions what we should to ?

Thank you

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests