A little advice and help please.

[2KGMC]

The issue is this.

At random points my transmission which is a 4l80e won't shift outta 2nd. It seems to happen when I go to give it gas to get into traffic but doesn't happen all the time and it pops a P0756 which is for the shift solenoid B. I've checked the grounds and all seem good I checked the pass through connector and it was soaked in ATF so I cleaned it up and put some dielectric grease on it to try and protect it. And it drove fine that day but the next day we went to a friends house and it drove fine there but on the way home I got maybe a half block from my house and it wouldn't shift out of second again. Only code it gives is the shift solenoid which is brand new.

Is it possible the valve body is clogged causeing this issue and would running sea foam through it help?

I've also changed the fluid and filter cause they were filthy when I got the truck and by filthy I mean the fluid looked like crap but no metal chunks just the usual muddy gunk on the magnet.

I'm not really wanting or in the position at the moment to throw $3k out for a transmission.

 

[skylark]

Here you go.
http://ls1tech.com/forums/automatic...ng-harness-leak-cause-eletrical-problems.html
http://www.fullsizechevy.com/forum/...984-why-does-4l80e-go-into-failsafe-mode.html

 

[2KGMC]

Thank you sir I'll have to recheck the connectors and then order a harness most likely which is still cheaper than another transmission.

 

[rhino]

Be sure and change the inside harness as well as the pigtail for that. I've had those pigtails look great but give me fits.

 

[2KGMC]

Thanks rhino I was thinking the same thing cause if I'm gonna be dropping the pan I might as well change the internal harness as an assembly pigtail and all. And I found one on eBay for $40 which compared to rock auto at $150 is cheaper choice. I'm also gonna change the fluid and filter again.

 

[2KGMC]

Anyone have any input on monster transmissions? Are they any good? In the event I have to replace my transmission I'd like to know where to go for a remanufactured one.

 

[kkirwan71]

Anyone have any input on monster transmissions? Are they any good? In the event I have to replace my transmission I'd like to know where to go for a remanufactured one.

I'd honestly have yours rebuilt by a local reputable shop. I went through the same thing a year ago but with a 700r4

ex gmt400 owner

 

[2KGMC]

If and that's a big IF I can find a reputable shop around here then that's what I'll do.

 

[df2x4]

I'd honestly have yours rebuilt by a local reputable shop. I went through the same thing a year ago but with a 700r4

ex gmt400 owner

X2. When my 4L60E in my red truck went out I asked my mechanic (who outsources transmission work) to treat it like it were his truck. Turn out he had a transmission guy one town over who's been in business for years. He built me one hell of a transmission. Asking around to the right people is the key.

 

[rhino]

What is your zip code? If you want I can look and see if I know anyone over there. I am on a few transmission re-builder forums and can look it up and see who is out there.