I built this 4l65e myself after taking it to the same guy 3 times within 1600 miles and finding out I got nothing I payed for. I made him give me a Beast sunshell, a piston kit,new 13v pump, new harness, new BW sprag, and a 2002 core, bit the bullet and learned to do it myself. I put a transgo shift kit in it, along with Alto frictions, I checked the input drum for leakage and it was fine, I put new steels in it, an overhaul kit from transtar, a .500 boost valve, new bushings, Wix Filter, new aluminum accumulators, and some other new stuff like solenoids, etc. I got a reman Trailblazer stall VJCX I think from transmission crafters. It has 2 coolers, a tube and fin and a bar/plate with 2 350 cfm fans on it(bypassed radiator). For about 4 months it worked great, except shift points but about 4 months later it started to slip the TCC once above 170 degrees in D or OD when locked at part throttle under a load (like right before it tries to unlock). If I drive it easy it doesnt slip except on steep inclines but who should have to baby around losing speed on hills. I bought HPtuners and changed the shift points and TCC lock/unlock mph. I even bumped up the pressure as I have been told tha would cause this. Everyone said it was slipping 3/4 but its been a year and I know it isnt because it pulls fine unlocked too the floor. The TCC is the problem, in some way or another. I even manually lock it in HP tuners while driving and it slips it. I have the pwm delete from the shift kit but also set HPtuners at 100max 90 min. This week I put in a new pwm lockup solenoid(gray connector) and a new TC snout solenoid because someone said it might be cracked and thats why it only slips when hot. when it is below 170 degrees it does NOT slip when locked. Also temp drops once i idle around town but on the highway it creeps to 170-190 in 100 degree weather and the hotter it gets the worse. The temps coming off the ooutlet side of cooler are 120 degrees idling on a hot 100 degree day, so I assume the cooler is working but it seems to get hottest when on the highway which doesnt make sense to me for a 2750 stall. Around town its 150 degrees driving it spirited with a 6000 pound truck. Any suggestions? When I lock the converter manually when idling with HPtuners it puts heavy load on the truck but doesnt stall it out completely, I didnt try the ball bearing test but I assume thats for people witha way to test it through the computer and dont expect different results. Also I could not blow through the old TCC snout solenoid(black) and I can blow through the new one(white), not sure why they are different it acts the same. Doesnt the cooler lube fluid have something to do with this circuit?

 

Nothing? Wow. I talked to the converter company and they said they would warranty it but I dont want to waste anyones money (mine or a reputable company's) if that isnt the issue. With HPtuners if I lock the converter while idling in drive when cold it will stall the engine. It puts a load on the engine but does not stall it out when hot (170degrees). It seems to directly be related to tempature as depending on fluid temp it stalls the engine less the hotter. Transmission Crafters said they put all new parts and friction in each converter core and its welded. He did mention it could be the rivets?? He suggested I put a sonnax part in the valvebody for TCC circuit, but I already have the Transgo kit that makes it on/off so I cant see that being the issue. He also said Sonnax makes a Oringed valve for the TCC valve in the pump above the TCC solenoid, but this pump was remanufactured and I even checked it before I installed it while installing the boost valve and it wasnt sloppy. Is there any way to test this further to determine what part is not working correctly?

 

Is the computer commanding lockup when it slips? High temps will cause the computer to disable lockup(as will various other things)

Any codes? You should get p1870 if the computer is commanding lockup but its slipping

 

Why are you running a trailblazer converter in a 6000 pound truck?
What kind of truck is it?
I have a '92 ext cab long bed 454 dually and it weighs 5800 pounds, not the place for a 60, 65, 70e. But thats just my opinion and I'm a ******* retard so **** me.

 

Self praise is no recommendation.

Maybe the same applies for self hate?

 

Whoa! Whoa!

What the Hell did I miss!!!

 

OK i re-read what you wrote (why does no one know how to use paragraphs)

After the system warms up, you loose lockup, even when commanding it with a scanner.

You said you did pwm delete, is that just through programming, or did you coil-bind the tcc regulator valve? I would first be looking at that valve to see if its leaking, as i believe that could cause your symptoms. Since your not using pwm you should install that fitzall valve or just use a longer spring to coil-bind the regulator valve and see if that alters the symptoms.

If thats not the issue, i'd check the apply valve has correct travel and the apply solenoid - does it hold pressure when commanded with a scanner?

 

Temps arent high by normal standards, 170 is where it starts to slip lockup and 185 is the high temp for me. I have 2 coolers, with 340cm server fans on the bar and plate in the grill, radiator bypassed. It has the Transgo orange shift kit, with the new valve and spring in the valvebody for PWM delete but I never had shutter or lockups issues before the converter/rebuild. My tune has PWM removed also. If I command lockup with HPtuners at idle when cold it stalls the engine immediatly, If I command it when 170, it loads the engine but doenst stall it out, at 185 it doesnt do much at all but for a split second. This was a reman 13v pump, but i took the tcc apply valve out of the pump and cleaned it when I installed the .500 boost valve and ground flats on the PR valve via transgo install sheet.

If I command lockup via HPtuners shouldnt it be bypassing the valvebody anyway and just using the TCC enable solenoid(not pwm apply solenoid) to force it into lockup? I pulled the inspection plate and the front of the converter is not discolored, so maybe it isnt damaged, but then again I try my hardest to drive it without making it slip as it raises temps making it a vicious cycle. I dont think it is my tune at this point, and maybe just tranny issues.

To the question about a TB stall in a heavy Denali, yes it smaller but the lockup clutch is about the same size and it woven carbon. Im not drag racing it as many do with the same converter and Im not locking it @ WoT. We are talking about pulling small grade hills in Georgia and it slipping under light throttle. People do pull trailers loaded down much heavier than my Denali in trailblazers Im sure, and the guy at Transmission Crafters didnt say there was anything wrong with my application..I was honest with him about the Vehicle, and mods done to it.

 

To the question about commanding lockup, yes. It isnt being diabled it slipping it while its commanded on via the Scanner App. No codes except an 1860 pending once when I was doing a second gear start and it shifted into first fora half a second and back to second. I also have misfire disabled because I thought maybe that was causing this but it made no difference. I have log files if that helps, and a few videos too.

 

Command lockup with the engine off. Does the solenoid click?

If you dropped a checkball in it and still have no lockup, maybe its your front stator bushing. Does the apply valve stroke when you push it with a pick?

 

It does click and command lockup. The valve above the TCC solenoid snout, or the one in the valvebody?

 

the apply valve is the one in the pump
The reg. valve is in the valve body...it regulates the pressure that goes to the tcc

 

the valve above the TCC solenoid snout in the pump, pull it out and install the valve first and then the spring. that will bind the valve into permanent lockup and the engine shoould stall as soon as you put it in drive. If it doesn't stall you've got a massive crossfeed leak somewhere and you'l probably have to pull the trans and find it.

 

Upgrade to a triple disc converter?

The only lock up issues Ive experienced was in my current trans am. It got so bad that on the highway I could manipulate the throttle to make it pull but then once power came on it would slip, or if I just put my foot down it would rev.

I had the trans out to install a yank ss3600 but it turned out to be a converter for a corvette. I bought it used and cheap. So not wanting to dump $900 into a converter for a bad trans I got a converter from advance auto for ~$125 to throw in there to test. Problems were solved after that. Thats the GM55 converter in my sig, Ive made about 6 1/4 mile passes and quite a few random runs on the street and I thought I needed a new transmission more than a new converter.

So for diagnostic purposes you could go get a new converter from advance auto, which will likely fail but buy you some time. or if you have the money buy a triple disc lock up converter which should help with the weight of your vehicle. My understanding is triple disc converters have stronger lock up abilitys.

 

Update! The converter company Transmission Crafters out of Albany GA swapped the converter for a new one. I had already added the Sonnax Teflon oring-ed TCC apply valve, the Techpak Fitzall oringed PWM valve in the valvebody this week, my VB bore wasnt worn, in fact I had to use the smallest orings and could barely get those in after copius amounts of transgel. I installed the Sonnax HD 2-3 shift valve since I had the VB out and crossdrilled the VB with 1/8 drillbit rather than notch it. None of that fixed it and it even seemed worse. I did find that my front stator bushing had some wear even though I had replaced it when rebuilding but this time I put the Sonnax extra wide bushing in, the input shaft had some wear on it there so I hope that fixes it. I understand that that is a sealing bushing and TCC apply oil comes in between that and the teflon resized sealing rings in the stator. The orange oring on the input shaft wasnt torn and all sealing rings looked good. I did manage to knock my band off when I pulled the pump but was able to get the ancor pin back in by dropping the valvebody after I found out I had no second gear.

Im going to test it out today and hope that it doens't slip once hot, I had to leave town as soon as I had fixed the band problem which was my fault. Im betting it was the front stator bushing the whole time, I just dont know what caused that wear...and it explains why it was fine for 4k miles after rebuild. It was my first full rebuild nad I could have overlooked something. Anything known to cause that bushing to wear prematurely?

 

The most common cause of the bushing to wear is improper installation damaging it while installing.
But over the years we have seen some strange ones, Bit of material partially blocking the feed in the orifice cup plug in pump that feeds the TCC SOLENOID, Leaking pump halves not true, We have even run into pump that were not machined deep enough to allow the sonnax valve to travel far enough to vent the release oil,
Even had one the opposite it was able to travel to far grabbed the Teflon ring and got stuck in lockup.

Overall the most common issue we see with lockup outside of bad solenoids however are pump related leaks.

Of course when you do mostly all 4L60E trans several a day and test them on Dyno you get to see all the really strange things regular trans shops would probably never run into.

The stator bushing may and hopefully will be you issue and all fixed , However if not I would seriously look to replace the pump.

One thing of note the best way to check for leaks is vacuum testing, However very shiny areas on the pump face and body can also be good indicators.

 

Op did you ever figure this out?