Allison 5sp: P0776 - Do I have big problems?

[Cougar281]

Mike, I was getting on my truck tonight and thought I limped it (felt just like limp when it dropped to 3rd and threw a CEL). Code I got was P0776 - PCS B Stuck Off. I found two threads with this code. One had no replies, and in the other, you indicated a tie up. I'll admit it's been a while since I changed the spinon. Is it possible it's just a dirty filter, or should I prepare to drop the trans for a clutch refresh? FWIW, I was running a 2001 TCM tune and a 330 HP PPE tune with defuel on.

Thanks,
Dave

 

[Mike L.]

Mike, I was getting on my truck tonight and thought I limped it (felt just like limp when it dropped to 3rd and threw a CEL). Code I got was P0776 - PCS B Stuck Off. I found two threads with this code. One had no replies, and in the other, you indicated a tie up. I'll admit it's been a while since I changed the spinon. Is it possible it's just a dirty filter, or should I prepare to drop the trans for a clutch refresh? FWIW, I was running a 2001 TCM tune and a 330 HP PPE tune with defuel on.

Thanks,
Dave

P0776 is my most feared code. It won't be just a spin on. I hope like hell you still have 4th gear. If it goes 1-2-3 then zing; you lost a P2 planet and C2 hub. P0776 is always serious shit.

 

[Cougar281]

P0776 is my most feared code. It won't be just a spin on. I hope like hell you still have 4th gear. If it goes 1-2-3 then zing; you lost a P2 planet and C2 hub. P0776 is always serious shit.

You just scared the crap out of me!

Anyway, the good news is I still have all gears. I'm assuming that if I killed my P2 Planet and C2 hub, it wouldn't matter if it was hot, cold, or somewhere in between, I'd have nothing after 3rd?

It felt like it was slipping on the 3-4, almost like the converter wasn't locked, then (relatively) slowly locked.

I'm guessing my best course of action is to turn the wick down, change my spin on, and plan on dropping my trans for a clutch refresh? Eric built it just about two years ago.

 

[beach_33]

so what out of curiosity happens on a sitiuation where a 776 code happens

 

[8100 Power]

And how come it's only lasted 2 years?? Sorry if i'm stepping on toes, but that's not very long with the mod's I see you having!?!?

 

[Cougar281]

And how come it's only lasted 2 years?? Sorry if i'm stepping on toes, but that's not very long with the mod's I see you having!?!?

Well, I'll admit I'm NOT easy on my truck... I drive it like I stole it. It SEEMS like my planet and hub are ok. I'm GUESSING that the reason for it doing this may be related to running with defuel disabled. I've ran with no defuel on the 330 tune until Mike warned about possible tie-ups, especially with the bigger tunes. Since then, I've run no defuel on the 90hp tune, but no bigger. I suspect this contributed to the weakening of the clutchpack. Also, after it was built, I almost always had what really felt like the 3-4 was binding up. No clue what was up. About a year ago, I got and installed a 6-speed valve body with a stock seperator plate. After that, the 3-4 was smooth as stock, no more jerky 3-4. So I don't know which was the largest contributor, but since I still have 4 & 5, I'm guessing the planet and hub are intact, and that the clutchpack is smoked or near smoked. Based on the way it felt, I'm guessing I was over powering the clutch.

 

[8100 Power]

Well, I'll admit I'm NOT easy on my truck... I drive it like I stole it. It SEEMS like my planet and hub are ok. I'm GUESSING that the reason for it doing this may be related to running with defuel disabled. I've ran with no defuel on the 330 tune until Mike warned about possible tie-ups, especially with the bigger tunes. Since then, I've run no defuel on the 90hp tune, but no bigger. I suspect this contributed to the weakening of the clutchpack. Also, after it was built, I almost always had what really felt like the 3-4 was binding up. No clue what was up. About a year ago, I got and installed a 6-speed valve body with a stock seperator plate. After that, the 3-4 was smooth as stock, no more jerky 3-4. So I don't know which was the largest contributor, but since I still have 4 & 5, I'm guessing the planet and hub are intact, and that the clutchpack is smoked or near smoked. Based on the way it felt, I'm guessing I was over powering the clutch.

Thanks for the explanation. I'm fixing to drop the bomb and have mine built in the next couple of weeks. SC IV w/1056.

Good luck on getting everything figured out

 

[Cougar281]

Well, it's hurt... BADLY. The fluid is NASTY, left a brownish-yellow residue on the rags. I bet half my clutchpack is in the fluid... Obviously, it needs help, but how much more damage am I risking by driving it as is, and would a flush help?

 

[TrentNell]

Well, it's hurt... BADLY. The fluid is NASTY, left a brownish-yellow residue on the rags. I bet half my clutchpack is in the fluid... Obviously, it needs help, but how much more damage am I risking by driving it as is, and would a flush help?

maybe its just me but there is no way i would keep driving my truck with that much debree in the fluid and the codes you are throwing , if you keep driving it and hose the converter it will likely cost more then fixing it right. if its only clutch packs it will be a cheep fix if your doing it yourself . is it possible that not having the holes drilled in the v/b spacer plate to case less pressure for the clutches and cause the clutch failures .

 

[Cougar281]

maybe its just me but there is no way i would keep driving my truck with that much debree in the fluid and the codes you are throwing , if you keep driving it and hose the converter it will likely cost more then fixing it right. if its only clutch packs it will be a cheep fix if your doing it yourself . is it possible that not having the holes drilled in the v/b spacer plate to case less pressure for the clutches and cause the clutch failures .

Eric (Dmaxallitech) built it almost two years ago. As I said eariler, the non defueled shifts and running a TCM in default mode may have contributed. Or it could be "normal" for a trans that's had 450hp put through it every day. Can ANYONE tell me what size drill bit to use for the holes in the plate or send me their used transgo/jr drill bit? The only reason I didn't drill them is I couldn't find what size the bit should be.

It's not throwing codes any more (only did it the once last night) and shifts fine, which is why I asked if a flush would help, but I think you're right...

 

[TrentNell]

Eric (Dmaxallitech) built it almost two years ago. As I said eariler, the non defueled shifts and running a TCM in default mode may have contributed. Or it could be "normal" for a trans that's had 450hp put through it every day. Can ANYONE tell me what size drill bit to use for the holes in the plate or send me their used transgo/jr drill bit? The only reason I didn't drill them is I couldn't find what size the bit should be.

i'll get the drill bit size for you later got to go out in the shop and track down my transgo instructions .and it wasnt the horsepower but probably a bit of all 3 trans tuning , no defuel, and valve body . sorry to hear of your failure .

 

[TrentNell]

drill bit size is .125

 

[Mike L.]

By not drilling the holes in the seperator plate, you negated the Transgo trim valves effects to leak mailine pressure to the C3 and C4 clutch which was only getting control main pressure. In other words you only had 50% clamping force on those clutches.

 

[paint94979]

By not drilling the holes in the seperator plate, you negated the Transgo trim valves effects to leak mailine pressure to the C3 and C4 clutch which was only getting control main pressure. In other words you only had 50% clamping force on those clutches.

Why would Eric do the install like this Mike?

 

[Cougar281]

drill bit size is .125

Thanks trentnell.

By not drilling the holes in the seperator plate, you negated the Transgo trim valves effects to leak mailine pressure to the C3 and C4 clutch which was only getting control main pressure. In other words you only had 50% clamping force on those clutches.

Well, it'll get fixed when I take it apart. Like I said, the only reason it didn't get done is no one could/would tell me what the size was.

We'll see how bad the carnage is.... HOPEFULLY it's isolated to a completely roasted clutchpack and nothing more.... When I do get it out and apart, I'll probably be calling you and/or Eric for advice/parts.

Why would Eric do the install like this Mike?

He didn't. I did. I put in a 6 speed VB, and before I put the VB in, I posted on at least dieselplace, and no one could or would tell me what sice the bit was... I have little or no doubt that I contributed to the failure with the non-defueled shifts, the VB not being drilled, running a 6 speed TCM in default mode, etc. Yes, I monkey with my stuff... Since the C3/C4 is getting 50% of the clamping force, it wouldn't shock me if I found that C2 overpowered and roasted the C3 clutchpack.

 

[Mike L.]

You could have called me.

 

[Cougar281]

You could have called me.

My bad... I play, I pay, right?

 

[Mike L.]

My bad... I play, I pay, right?

Next time call me.:hug:

 

[Cougar281]

Next time call me.:hug:

When I get it out and apart, I will

 

[GMC_2002_Dmax]

And how come it's only lasted 2 years?? Sorry if i'm stepping on toes, but that's not very long with the mod's I see you having!?!?

Running a TCM with defuel shut off is a IMHO a very poor decision to make, either by the tuner supplying the TCM file or the end user deciding to go with out defuel on the shifts...............

I am not even sure if it was even a good idea to release it from BETA as I warned about running a TCM with it turned off, and you are not the first to ruin a transmission by running with the defuel shut off.............

Sorry to hear that it killed the transmission.........

Well, I'll admit I'm NOT easy on my truck... I drive it like I stole it. It SEEMS like my planet and hub are ok. I'm GUESSING that the reason for it doing this may be related to running with defuel disabled. I've ran with no defuel on the 330 tune until Mike warned about possible tie-ups, especially with the bigger tunes. Since then, I've run no defuel on the 90hp tune, but no bigger. I suspect this contributed to the weakening of the clutchpack. Also, after it was built, I almost always had what really felt like the 3-4 was binding up. No clue what was up. About a year ago, I got and installed a 6-speed valve body with a stock seperator plate. After that, the 3-4 was smooth as stock, no more jerky 3-4. So I don't know which was the largest contributor, but since I still have 4 & 5, I'm guessing the planet and hub are intact, and that the clutchpack is smoked or near smoked. Based on the way it felt, I'm guessing I was over powering the clutch.

I ran the heck out of mine for a lot longer with many, many runs, and when Dipper tore into mine for a refresh he didn't find much if anything wrong.......I ran N20 and put over 500 RWHP thru it daily for 3 1/2 years and 90K miles..........but I was running the stock 2001 TCM program............

Eric (Dmaxallitech) built it almost two years ago. As I said eariler, the non defueled shifts and running a TCM in default mode may have contributed. Or it could be "normal" for a trans that's had 450hp put through it every day. Can ANYONE tell me what size drill bit to use for the holes in the plate or send me their used transgo/jr drill bit? The only reason I didn't drill them is I couldn't find what size the bit should be.

It's not throwing codes any more (only did it the once last night) and shifts fine, which is why I asked if a flush would help, but I think you're right...

I think unfortunately the issues were from running that modded TCM tune and as Mike stated the pressure drop from not drilling the VB.

Hope you get it up and running, and ditch that TCM tune for one with defueled shifts and warn everyone else that it is not worth it................:hug: