Which Solenoid, controls fluid pressure to reverse ? Sluggish going in to Reverse. Or is it better to replace all four solenoids, and pressure manifold ? All pieces for $150 including shipping. Leaning towards', replacing all the solenoids while I am under there. I already know, it is not the bands or converter.
if you're gonna drop the pan, just replace all of it. make sure its not your reverse accumulator piston seal.
Forward and reverse in an 4l80 are hydraulic only. No electrical takes place at that point. Low/reverse band and direct clutch on at the same time get you reverse. As mentioned above you could have a bad seal on the reverse band servo. Cracked rear servo piston, friction material worn off the rear band, direct clutch sealing issue and or clutch problem, low line pressure. How is the 2-3 shift? Direct clutch also comes on in 3rd gear. If its just reverse it narrows it down somewhat. Thats all i can think of right now....
On a 4l80e. Which trans line is the high side ? front or back line. Going to check line pressure, before I remove it to replace all the solenoids. I think, it is the front line. Yes! I have to remove it , as there is a nonremovable crossmember under it. .
Those are the cooler lines. U need locate the pressure port Sent from my DROID device using the TJJ mobile app
Alteredpilot: Thank you. You are correct. Here is the test page I found for a 4l80e. This test. will work for most transmissions . Test port will differ, on other transmissions. http://www.tvmadeez.com/press_gauge/pressgauge.html http://www.tvmadeez.com/pressure_test/index.html .
to do the line pressure test you'll also need a bi-directional scanner to change the amperage of the pressure control solenoid to verify it's operation.
Would anyone out there have any advice regarding a 4l80e that drops out of o.d. after about 15 min of driving? OD will not re-engage until vehicle is pulled over and shut off and restarted, then od engages normally again. The shop said there were no codes on it and the pressures were normal. It seems like a sensor issue but I'm not sure what to replace, it talks to so many sensors. The knock sensor has been replaced, I'm wondering if it could be TPS related. I sure miss the old vacuum modulator days.
Google 4l80e droping out of OD http://www.google.com/webhp?sa=N&ta...pw.r_qf.&fp=577e53bc82978f0e&biw=1600&bih=666 The link below is just one I found. http://chevytruckworld.tenmagazines.com/ew/forums/topic.asp?id=143300 .
Anyone familiar with Trans Go Valve body mod's. I unbolted the valve body, very careful not to lose anything There is to be 8 total, 1/4 inch check balls. There is only 7 check balls. In the pictures are there locations. Passage #37 forth clutch is not there. The trans has worked great until a solenoid failed, that is why it is apart. Is this missing ball part of Trans Go's modification they do ? In the pictures is the location of the missing ball Remember this is a 4l80e Today being a holiday, I'll call the builder tomorrow. http://[B]www.transmissioncenter.net/4l80e.htm[/B] Went back and looked at the valve body plate, and there are two passages welded closed. Both thing's, that are strange, are in the forth gear pressure passages. One is marked pressure relief Well I'l just have to wait till the AM .
Call builder today, and the missing check ball is normal for this build. The trans was built with the knowledge that the truck weighs 4000 lbs plus. Very impressed with their help. This is not spam. Just a very good vender. http://www.transmissioncenter.org/contact_page.htm http://www.transmissioncenter.net/
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