4L60E TCC Problem SOLVED

[KingPin_Chevy86]

So I had originally posted a few yrs ago about a problem that I was having with the TCC not kicking in when the outside temp was over 50* in my 1997 tahoe L31/4L60E. To make a long story short, the truck would act normal when you first start out in the morning but has the truck reaches opp temp and the outside temp was over 50* then the trans goes 1st, 2nd, 3rd, 4th, no lock up. then after you ride with no lock in 4th for a period of about 10-15 minutes, there would be a serious kick from 1st- 2nd, 2nd- 3rd, and third would slip hard. I found this article just screwing around on google trying to solve this as its becoming spring time and the temp here in NE Ohio is getting warmer. I needed to get this together. Granted the truck has 214,000 Miles but has been maintenanced like a senior at a nursing home so aside from the rust, its a pretty good truck. Heres the article I found:

My last truck was a 99 1/2 ton 4.8L with the 4L60E, I had the same problem. No trouble codes were set, so I took the dealers tranny guy for test drive, he brought along his tech 2 scan tool. As we were driving I told him what exactly happened and when. He picked it up on his scan tool right when I said it was going to pop out fo OD.
The problem was two fold, part of the problem was the tcc solonoid, the other half of the problem was the port on the valve body where the tcc solonoid seals off. See, the tcc solonoid is sort of a proportioning valve, it has a steel ball that opens and closes and that steel ball seals off on port in the aluminum valve body. See where I'm going here, , steel vs. aluminum? Any way, the steel ball starts to peen away the surface of the aluminum valve body, when the fluid gets warm (that's when mine did it) the fluid thins out some and leaks past this "improper" sealing surface and it messes with the line pressure.
The fix - the dealer pulled the vlave body and took it to a machine shop where they reamed out that port, installed a steel insert, so now the steel ball in the tcc solonoid can seal off on steel surface. $450.00 problem solved.


Also check out the TransGo SK4L60E kit, it has a fix for this problem in the kit. I just ordered the kit and will be installing it in the near future. I hope this post helps anyone out there that has been chasine their tail like I have for three yrs now.

 

[rhino]

Hmmmm...That really sounds good. But.... I don't think it's 100% correct. The bore they reamed out, is most likely the TCC Isolator valve bore. Its extremely common. Boring out the valve was the fix years ago, but since then a simple drop in valve with o-rings is the most common. They put a steel valve in an aluminum valve body, which is not uncommon, but the valve is constantly osculating so that's where the wear comes from. The drop in valve is about 15 bucks. I can tell you it works.. bottom line.

 

[KingPin_Chevy86]

Where did u get the valve. I was actually about to drop $300 on a complete reman valve body and new solenoids. But if I can get away with just that TCC Isolator valve bore for $15 and a couple hours in my garage then Im all for it. I was only gonna replace the complete valve body because the truck has 214,000+ on it and is 100% original. It was like a precaution.

 

[DGA1]

Do a google search for "Teckpak TCC Isolator Valve" and you'll find places.

Here is a instruction sheet from Teckpak on it's installation.
http://www.teckpak.com/datasheets/4L60E TCC valve.PDF

 

[KingPin_Chevy86]

ok cool. thanx.

 

[Mrich0908]

I just replaced the valve , its simple and straight forawrd. The valves
exact name is TechPak PN# A74741Q
I used this company they are very reasonable.
http://www.transmissionpartsusa.com/4L60E_Transmission_TCC_PWM_Valve_Repair_p/350-00a74741q.htm
http://helpwrench.com/forums/showth...uide-with-Pictures-Tips-Pics-and-Tricks/page4
This isnt my picture it came from this great write up I refereed to time and time again! Along with the Boxwrench DVD for the 4L60E rebuild.

You must be registered for see images attach

 

[scmsltn]

Did it make a difference in yours? That is a great pic.....how long was the install?

 

[pElf28p]

Hey DGA1, Thanks for the install directions for the TCC. At the bottom of the instructions it says P.S. coming soon how to install the TCC without removing the valve body. Do you happen to have that or does anyone for that matter, know a link of how to install the TCC fix with transmission still on my truck? Thanks.

 

[Mrich0908]

I didnt do my removal and install all at once Ive had time to do some here and there. I bought the box wrench DVD converted it to watch on my HTC Amaze Android phone. Just followed along . It was simple enough for me .
As far as the TekPak Valve . I Never popped a code P1870 , but the builders Ive talked to swear by this fix . They recommend to install it prior to needing it.
I cant tell the difference so it must be working.
But just installing the valve its self probably isnt that hard. If you get that far into the 4L60E I say replace the 2/4 servo adjust the TCC valve for firmer shifts I believe its a 1/4 turn CW . GM has a campaign to take a check ball out above the valve body thats held in by a C clip and REPLACE your SunShell Gear . Because its on its way out if your transmission has 80K+

 

[DGA1]

Hey DGA1, Thanks for the install directions for the TCC. At the bottom of the instructions it says P.S. coming soon how to install the TCC without removing the valve body. Do you happen to have that or does anyone for that matter, know a link of how to install the TCC fix with transmission still on my truck? Thanks.

Sorry no idea. It says to call the manufacturer if you'd like to know the details. If you do let us know what it is...I've been wondering myself.