I don't think he checked for leaks the first build but this last one he did. I had a spare trans he ended up using allot of also. He spent about about a week making sure all the material was out of everything. I'm just afraid I'm missing something now in the tune or from the PCM swap. Guess I will go and try and get the VE closer today and just enjoy our vary rare 65 deg winter day
I appreciate all the suggestions and help.
When he assembles the 3/4 clutch pack, he has to air pressure test it, and again when he installs it into the case.
He also has to make sure the VB is flat, and that the case is flat where the VB mates to.
175 miles of logs and seeming fine and was just planning on enjoying the day driving it without looking at my laptop and like an idiot got baited into a wot hit rolling into it from 2nd and it didn't even try to grab 3rd and now 3rd is gone
That's a real bummer.
After that many transmission failures, I'd be looking for a new builder.
That points to internal leakage.
+1 new builder, find one who specializes in 4L60E/65E and nothing else.
See attached pages of 4L60E HMTG, they show hydraulic components involved in 3rd gear, leakage at any of these or in the circuit will comprise 3rd gear (and 4th gear since it shares the 3/4 clutch).
So now my trans builder thinks it's the PCM. When the transmission is unplugged and defaults to 3rd it works and doesn't slip. He plans on coming by with a test harness and new pressure manifold, and other parts to swap and see what happens this Saturday
All the testing an diagnostic's should have been done before the test drive. Tell him to bring a pressure gauge and a tech 2. Or just tell to him stay home and find a new builder.Originally Posted by TLKSCHP
My transmission builder came over and spent some time looking and testing things this weekend. He is stumped and typed up this to post on a transmission forum he is on. I thought I would share it here
Car is tuned with EFI Live.
First time after the blower install, the modulator blew causing low line pressure and smoking the clutches. Replaced all wear items, installed beast sunshell, reinstalled EPC, and checked valve body. Air checked.
Second time car made several hits, few hundred miles, and burned the 3-4 clutches but all clutches showed wear as if a pressure issue. Replaced all the clutches, swapped valve body, installed Sonnax boost valve, and air checked everything again.
Put 40 easy miles on and hooked up the tech 2 to monitor demanded amps to the EPC to see if the tune was commanding properly. Drove great, shifted great and everything appeared to being commanded properly per the tech 2. Stopped and did a WOT pass. On the 2-3 shift, the car shuttered hard and neutraled. After that, it would neutral on the 2-3 shift. Pulled the filter apart and it was full of clutch material. Tore the trans down and all clutches showed signs of wear that would indicate a pressure loss. This material was broadcast throughout including plugging ever filter in the valve body and the screens of all solenoids. I had never seen this happens so I showed some old builders who said it wasn’t the Dacron from the filter but friction material. Sent converter off for rebuild as it was the first time it was opened in 8-10 years with a few trans rebuilds over the years before I touched it. Replaced all the Torrington bearings because this material was wrapped up in everything. Trans goes back in the car and he puts 150 ~ miles of part to 3/4 throttle per converter builder recommendations. After that, makes a rolling into WOT and the car makes the 2-3 no problem. Stops and does a full WOT pass and on the 2-3 shift, it neutrals. Doesn’t shutter like before.
Unplugged the trans and in shifter position 3 or 4, the car moves. So, I think mechanical 3rd is there but it pulls like it’s in second. We go drive the car with the fuse to the trans pulled. Put the shifter in manual second and start to drive up, manually shift to 3rd and it neutrals. Tells me 3rd gear is in fact not there. Put a gauge on it and pressures match what they are commanded. Commanded pressures were matching amp. Max the scanner showed commanded was .2 amps and the gauge was showing 180-185 psi. To add to my confusion, it did something I have never seen before. When we did a WOT in second, on the 2-3 shift the pressure jumped to 240 psi and the commanded amps still showed .2, then the pressure dropped to 90psi. I was not quick enough to know if the drop was as he let out of the throttle or right before. The 240 spike lasted maybe a second, it was fast.
Which trans forum did he post on, I want to read the replies...
What rpm are the WOT shifts at...?
What HP and TQ is engine making...?
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