So your trans isn't slipping...?

 

Absolutely no signs of slipping since I got it back from rebuild about 200 miles ago.

The original rebuild was slipping in 4th, that's why I took it back into the shop.

 

You can post the name and city of the shop, just not the exact address, nor phone number, nor website. The forum rules are more concerned about a non-sponsor promoting themselves; not so much a member recommending a good shop. Sometimes a shop "pays" customers to promote them on this forum, but I can see through that.

 

Maybe I missed it, what tune or who tuned this trans?

 

Thanks mrvedit...

Tuner is Travis from Fast Specialties in Vancouver WA. I have known him for many years now, have worked with him and my brother-in-law on several turbo builds over the years.

Trans shop that I was super happy with yesterday was Metro Transmission in Woodland WA. I felt he was by far the most knowledgeable person I have talked to yet(in person) about this transmission and this issue.

 

Not much was done to the "tune".
VATS, EGR/emissions stuff removed.
Minimal timing increase.
1-2 shift mph increased by 3 mph, I don't like this one and will be having it changed back soon.

 

If you or anyone is interested I will volunteer a great trans tune for the 4l60e. Ive been running the same tune in my personal car for 7 years, its in my daily driver, and its in quite a few other cars ive tuned over the years. No trans failures to date including my own original trans in a buddys car with over 150k on it.

 

I'm interested...

 

I'm also interested.

 

That would be great to get that tune if your willing to share.

Is it just a file that you can email?

 

Yes, PM me if you want it. You would need HPTuners software to view it.

 

Quick update on this transmission.

I have now talked to three shops(besides the one that did the rebuild), and were able to drive the truck with my line pressure guage visible in the truck(ziptied to the heater control). All three shops said that the computer was controlling line pressure correctly and that the pressure numbers looked excellent.

I guess I need to go back and have a conversation with the shop that did the rebuild now.

 

New update on this, hopefully closing this thread out. Hate threads with zero problem resolution.

I went back to the shop that did the rebuild to ask what was really going on since three other shops saw no issues. I went ofr a ride with the tech and he was able to make the pressure guage have a weird reading. Basically it was not always increasing line pressure when it was commanded by the ECU. We went back to the shop and he unhooked the trans wiring from my computer and installed their control box to manually control the transmission, he was able to replicate the problem, indicating that there was a problem in the transmission and NOT in my computer/wiring like they originally tried to blame the problem on.

Even after seeing the tech make the problem appear on the guage, I could not repeat the guage issue myself
I leave the truck at the shop to get it fixed. Hoping some of you might be able to shed light on this. They said these transmission have a variable output pump and there is a part that has to slide freely for the variable output to allow the pressure increase. This sliding part was not sliding freely and therefore would occasionally give low line pressure. Not sure what they did this time when they had it apart to fix it though. Time will tell, hopefully it lasts this time.

Anybody know what this sliding thing is? And what might have been done to fix it? Is it a common problem?

 

The pump has a spring-loaded sliding ring which changes the volume swept by the vanes... the output of the pump (going thru the pressure regulator valve) feeds one end of the sliding ring to regulate pump output in a negative feedback closed loop manner.

Sounds like the tech knows about it and how to induce it.

Question is why did they not take care if this when they had the trans out/apart the first time.

 

Exactly what joecar said. Too many rebuilds involve shortcuts to save money and/or time.
He is a picture of the pump internals including the slide-ring and its spring.
(The red is ATF I used as a pre-lube.)

 

Rebuilt 4L60e pressure issues. Right after the rebuild the pressure was 200 psi in every gear, warm and cold. Drove and shifted exactly as it was supposed to with the exception of a hard 1-2 shift due to the high line pressure. Dropped the pan to put a new EPC solenoid in and changed my pressure manifold switch. Also inspected boost sleeve and PR valve which moved freely. Put a new filter in, put the pan back on, put about 10 quarts in it which was way too much fluid—a few quarts puked out the vent and dipstick. Now my line pressure is 25 psi in every range, which is too low to even apply clutches so the truck doesn’t move. I am not trying to drive it or run it. Did I cause a cross leak in the valve body by removing the 10 mm bolts that hold the pressure manifold switch? Did I accidentally break my filter neck when I put the pan on? Is my new EPC faulty? Thanks for any and all help here.

 

The first thing i will check is the fluid level.
First, Start the car and check the level, and then shut down the car and check for level. If the level stays the same that means you possibly broke your pump rotor.

The thing is, your base oil pressure is mechanical. And even if you had a small leak, it would build pressure.
The pump sucks ATF directly from the pan and lowers the pan capacity when the car is running.