Tranny acting up on built Lmm

[Nickracer9]

So truck has been kinda shifting hard into gear the last week or so and then down shifting from 4-3-2-1 it sometimes really shakes the truck. Doesn’t do it every time but every few times. Thought it was my a/c running as temps have got a lot hotter thus affecting the shifting/tuning. Well today I was getting a coffee and I noticed the engine temp getting warmer and warmer. As it climbed from 190 to 215 just at idle. So as I left it was stuck in 1st gear then would rev up and then all of a sudden it locked up and I could hear the rear tires almost skidding. Stopped, turn truck off for a couple minutes and it was fine. Whole way home it was normal then it stuck in 4th gear when I pulled into my development(no code). Really seems heat related but for the most part temps were within a hundred degrees of ambient 190-200. Any ideas? Truck is built lml in a lmm with built trans and compounds(1000whp).Also have a fleece alli locker and I def get my share of p0700 when it’s turned on. Disconnected it after today and it was still acting up. Thanks again.

Sent from my iPhone

 

[48548]

You need to use a better code reader. 700 is a generic trans default code. A tech 2 or mdi would work.

Sent from my SM-G955U using Tapatalk

 

[Harbin_22]

Who built the trans

 

[Nickracer9]

Sdp, I’m waiting to hear back what he thinks. It feels like the tranny is running like full fluid pressure at light throttle. I let the truck cool off and it drives ok but still the aggressive shifts. I did recently change the spin on filter and the magnet looked pretty clean. Idk?!?

 

[Mike L.]

Maybe a broken spring in the trim valve bore.

 

[Nickracer9]

I was gonna drop the pan and take a look. Is there a way to check oil pressure or codes with efilive that the edge cts might not be seeing? Thanks

 

[Nickracer9]

Tech2 said p0777 pressure control solenoid number 2 stuck on and p0732 incorrect second gear ratio. Seems to shift up ok but can’t shift back down from 4th gear and then it’s stuck in 4th with a CEL. Any ideas? We did try a new tcm as well. Thanks.

 

[SickLL7Crenshaw]

Is the TCM tuned? If so by who?

 

[Nickracer9]

I’ve tried a tuned tcm by Mark and a new stock lmm tcm. Same issue.

 

[Nickracer9]

Well I was pulling the psm(pressure sensing module I think?)off the valve body and noticed that one oring is blown out and another is questionable. Should I stop here or pull the trim valves out too? Thanks guys!!! Feel like I’m getting close

 

[Mike L.]

Well I was pulling the psm(pressure sensing module I think?)off the valve body and noticed that one oring is blown out and another is questionable. Should I stop here or pull the trim valves out too? Thanks guys!!! Feel like I’m getting close

Looks like you found it.

 

[Nickracer9]

Thanks Mike. I’m gonna leave the trim valves alone for now. These orings really look degraded though.

 

[Nickracer9]

That oring fixed it! Finally back on the road

 

[2004LB7]

Thanks for the update. Not everyone gets back after a repair

 

[Nickracer9]

I spoke to soon, started acting up a bit. Drove it for a while just fine and then I went to tow haul and it’s kinda aggressive with the downshifts, like the rear tires squeal from 4-3. Thought I had it :/

 

[Mike L.]

Tow Haul is on a different strategy and will have to learn on its own.

 

[Nickracer9]

Yeah I’m hoping I was just low on fluid cause it got stuck in 4th gear and when I got home the gear indicator was blinking and wouldn’t go into gear. Checked fluid and it appeared low so I added a quart. Really hard to read the dipstick though. It’s shifting again okay but towhaul is definitely more clunky at the moment. I’ll know more after work today.

 

[Nickracer9]

Ended up pulling it out and the c3’s are smoked. Gonna pull the c1-c2 drum apart next and see how those look. Any other things I should check? Thanks guys!