lb7 tranny actin up

[dracing70]

well just went out for a spin and out of no were my lb7 tranny just went crazy it keeps hittin nuetral revin then jammin into gear and now it is slippin like crazy and it happened out of no were under no load . i have a number of codes p0872,p0777,p0836,p07000 someone let me know what they think? whether its mechanical or electrical or what???

 

[paint94979]

P0872
Pressure Switch Solenoid E Circuit Low/Stuck Closed

P0777
Clutch Pressure Control (PC) Solenoid 2 - Stuck On

P0700
Transmission Control Module (TCM) Requested MIL Illumination

P0836
That isn't a known code.

 

[dracing70]

so were should i start?? does it sound like all solonoid and electrical issues ??

 

[paint94979]

so were should i start?? does it sound like all solonoid and electrical issues ??

i'd drop the pan to look for any abnormal amount of material in there

 

[Akdiesel]

I'd also give Mike a PM or call...

 

[x MadMAX DIESEL]

I'd start with adding all your trucks and their mods to your sig, you seem to deal with a couple... That can only help :thumb: Sorry I have no input

 

[dracing70]

yeah i plan on it. anyway if anyone has a sec i will give the whole scoop cuz i am puzzled. this happened on my lb7 dually. it has a stage five suncoast kit in it . it was a solid tranny . probably has about 70000 on the modded tranny . anyway i was toolin around town pulled into driveway and sat for a sec like always to let it cool down. i noticed egt would not go down past 550 degrees usually i let cool to 300 then shut off. so i revved it to see if gauge was functioning and it kind of loaded up and stalled. went to restart and it did not crank very reassuring. took it out to check and it popped the engine light. and the tranny seemed like it was slippin out of no where. i clicked on race tune and went to hammer it . and it hit nuetral revved to the moon then punched back into gear makin a nasty nasty racket. i imediately pulled in and it barely goes in drive slippin like hell although reverse seems just fine..

 

[Mike L.]

I would be checking output speed sensor or the tone wheel in the transfer case. Your transfer case could be going out. I don't like the 872 code as that indicates a stuck E shift valve. That would indicate trash in the valve body. Go for the TC first.

 

[dracing70]

the t case did give me some trouble a few weeks ago. it keeps putting itself into nuetral electronically but not mechanically not to mention after you put it into 4 lo it sometimes will not go back into 2wd or 4 wd high and it even popped into 4 lo on the selector one day on its own although it was still in 2wd high it read lo but was in high until i turned it off and it sat for awhile.

 

[JoshH]

yeah i plan on it. anyway if anyone has a sec i will give the whole scoop cuz i am puzzled. this happened on my lb7 dually. it has a stage five suncoast kit in it . it was a solid tranny . probably has about 70000 on the modded tranny . anyway i was toolin around town pulled into driveway and sat for a sec like always to let it cool down. i noticed egt would not go down past 550 degrees usually i let cool to 300 then shut off. so i revved it to see if gauge was functioning and it kind of loaded up and stalled. went to restart and it did not crank very reassuring. took it out to check and it popped the engine light. and the tranny seemed like it was slippin out of no where. i clicked on race tune and went to hammer it . and it hit nuetral revved to the moon then punched back into gear makin a nasty nasty racket. i imediately pulled in and it barely goes in drive slippin like hell although reverse seems just fine..

Maybe a problem with C1 clutches?

 

[Mike L.]

Maybe a problem with C1 clutches?

Josh
If you disconnect your OSS the truck will barely go forward. Not saying it isn't C1 but easier to check.

 

[dracing70]

my question about the c1 s is why would it do it out of no where under no load . it was fine then turned the truck off then on and it all of a sudden mucked up..

 

[dracing70]

well mike you were right. i pulled the transfer case out of my lly and put it in my lb7. it seems that the transfer case was the problem. now i have to diagnose. so what is the best option? should i just pick up a new transfer case or should i just fix the original one? any suggestions would be greatly appreciated.

 

[THEFERMANATOR]

well mike you were right. i pulled the transfer case out of my lly and put it in my lb7. it seems that the transfer case was the problem. now i have to diagnose. so what is the best option? should i just pick up a new transfer case or should i just fix the original one? any suggestions would be greatly appreciated.

Was the old transfer case empty of fluid? Theres a good chance all it needs is the nylons that go on the range shift fork as they get brittle and break off allowing the low high selector slider to float in there in neutral. It could end up being a cheap fix.

 

[Mike L.]

well mike you were right. i pulled the transfer case out of my lly and put it in my lb7. it seems that the transfer case was the problem. now i have to diagnose. so what is the best option? should i just pick up a new transfer case or should i just fix the original one? any suggestions would be greatly appreciated.

What you do with the bad TC depends on the damage inside. I have a feeling it might be heavy. Pricing out the new parts to fix it may be a lot more than picking up another unit.

 

[dracing70]

Was the old transfer case empty of fluid? Theres a good chance all it needs is the nylons that go on the range shift fork as they get brittle and break off allowing the low high selector slider to float in there in neutral. It could end up being a cheap fix.

i think the fluid might have been the problem. the damn tailshaft seal has been bad for a while and i was adding every so often but i think it went dry. it had been acting wierd prior to this . it would go to nuetral on the selector on its own and once in awhile it would even put itself electronically into 4 lo.

 

[dracing70]

well mike you were right. i pulled the transfer case out of my lly and put it in my lb7. it seems that the transfer case was the problem. now i have to diagnose. so what is the best option? should i just pick up a new transfer case or should i just fix the original one? any suggestions would be greatly appreciated.

well another premature diagonsis.. i took the truck out this morning and went about six or so miles with it. as soon as it warmed up and i gave it a bit of throttle i limped and popped the code again. 0872 fluid pressure sensor code. what next?? do u think this is fixable without pullin the trans. i am just fed up with rippin trucks apart. let me know what u think??????? i am ready to burn this thing..

 

[Mike L.]

I was afraid you might have 2 separate problems. Pull the pan and see if there is crap in the pan. If there is, the trans is coming out. If there isn't, pull valve body and clean E shift valve bore.

 

[dracing70]

well mike i ripped her apart fully disassembled the valve body and cleaned. it was quite dirty . i put back together replaced spin on and filter, then took for a ten mile drive. seems to b fine so far. i will drive to work all week and see if she hold out but so far so good.
thanx for all your help

 

[dracing70]

Well got about 20 miles and it dicked up again