no movement forward from stop

[whyte]

no movement forward from stop
2011 ram 3500 6.7L engages 1st gear(audible feelable) then slips out after 10' (loss of forward movement..no sound or jerk)when cold and almost instantly when brake removed warmed up. was stuck in snow. bully dog chip(used for delete) shows p2706 p0731 p0933. 4x4 low drive works in both directions fine (yes i know how to switch out low properly) 4x4high and 2x4 issue occurs, reverse is fine. performed trans fluid/filters change (perhaps some sludge on pan nothing too alarming to this country boy, no filings seeminly good for 120k km). replaced the gov pressure solenoid. checked shift linkage. reset engine and cleared codes. does not allow to start in another gear when selected(normal i believe) however if i get it at appropriate speed for a shift my baby operates normal(managed to make it home until forced to stop help!!!! i know all of what it could be but what IS IT! what tests do you recommend (instructable)


ill buy your coffee at Tim Hortons in the morning

 

[whyte]

here are the codes

 

[transe]

Stuck in snow.... bully dog chip.... congratulations, you have a failed overrunning clutch. This is a mechanical one-way clutch (at the very back of the transmission). You'll have to pull the trans and tear it completely down to get to the overrunning clutch and replace it. For the time being, you should also be able to drive it OK if you start off in manual "1" and then tap it up (to "D") after you get past the normal 1-2 shift point. Gears 2 thru 6 should be OK. The problem is that, with the ORC failed, the trans will neutral out when the LR clutch releases. Putting it in manual "1" will hold the LR clutch on.

 

[TCDiesel]

Stuck in snow.... bully dog chip.... congratulations, you have a failed overrunning clutch. This is a mechanical one-way clutch (at the very back of the transmission). You'll have to pull the trans and tear it completely down to get to the overrunning clutch and replace it. For the time being, you should also be able to drive it OK if you start off in manual "1" and then tap it up (to "D") after you get past the normal 1-2 shift point. Gears 2 thru 6 should be OK. The problem is that, with the ORC failed, the trans will neutral out when the LR clutch releases. Putting it in manual "1" will hold the LR clutch on.

Before I finished the 1st sentence that was My thought, Just confirming the experts opinion.. OP your wallet will be taking a huge withdraw on the repair done correctly.

 

[whyte]

i did consider ORC as cuprit but the fact that it operates normal in 4low threw me off. explanation?

 

[whyte]

and would the transmission not have a different code for the clutch?

 

[transe]

i did consider ORC as cuprit but the fact that it operates normal in 4low threw me off. explanation?

I believe that in 4LO range, the LR clutch remains applied all the time in 1st gear (similar to running in manual "1").

 

[whyte]

I believe that in 4LO range, the LR clutch remains applied all the time in 1st gear (similar to running in manual "1").

ok. by manually selecting gear 1 (electronically i should say) the trans still slips*

 

[transe]

ok. by manually selecting gear 1 (electronically i should say) the trans still slips*

Restart the engine, then shift to Drive, then tap it to "1" before you move the truck at all. It should then work OK. Once driving, tap it back to "1" manually (when coming to a stop) BEFORE it would normally downshift to 1st on its own.

 

[whyte]

no joy. man1 still slip

 

[transe]

no joy. man1 still slip

Does Reverse work OK?

 

[whyte]

Does Reverse work OK?

r is normal

 

[transe]

r is normal

OK, and you said 2nd thru 6th gears work OK also? When you put it in Drive, do you get any engagement at all? If it does engage, does it feel like the trans is locked up (or as if the brakes are applied)? Or does it just slip, like it's in Neutral? Did the fluid smell burned? Are you still getting the P2706 fault, or just P0731 / P0933?

 

[whyte]

OK, and you said 2nd thru 6th gears work OK also? When you put it in Drive, do you get any engagement at all? If it does engage, does it feel like the trans is locked up (or as if the brakes are applied)? Or does it just slip, like it's in Neutral? Did the fluid smell burned? Are you still getting the P2706 fault, or just P0731 / P0933?

2-6 and even 1st work if as long as speed is above say 15km/hr it will not electronically shift to 2nd until moving at about that speed after clearin i get p0731 and p0933 the 3rd code dissapeared. * when out in park it engages normal. but of a pull and audible switch into gear then when brake released it acts exactly like if it were in neutral (although when cold it will move 10 yards then without any sign it just acts like its in neutral) *fluid did not seem burnt was a bit of sludge on pan had to use a cleaner to remove.. could have been her first transmission change in 120k km so i i expected some buildup.
should say also to get it home i was able to get enough speed for a upshift by putting in drive then when it slipped knocking it into neutral and back to gear*

 

[transe]

2-6 and even 1st work if as long as speed is above say 15km/hr it will not electronically shift to 2nd until moving at about that speed after clearin i get p0731 and p0933 the 3rd code dissapeared. * when out in park it engages normal. but of a pull and audible switch into gear then when brake released it acts exactly like if it were in neutral (although when cold it will move 10 yards then without any sign it just acts like its in neutral) *fluid did not seem burnt was a bit of sludge on pan had to use a cleaner to remove.. could have been her first transmission change in 120k km so i i expected some buildup.
should say also to get it home i was able to get enough speed for a upshift by putting in drive then when it slipped knocking it into neutral and back to gear*

Your overall symptoms don't make sense. To drive in 1st gear, you need the UD clutch to hold, along with the overrunning clutch (ORC) and/or the LR clutch (either one will work). The LR clutch must also hold in Reverse, so since your Reverse works OK we know the LR clutch works. LR should be applied at a dead stop in Drive (or manual "1"), so if trans is slipping then that would point to a bad UD clutch. But UD is also needed for 2nd and 3rd gears, so if UD were fried / bad, then trans should also slip in 2nd and 3rd.
So if you shut the truck off, clear the faults, then restart it, then shift into Drive (at a dead stop), does it set the P0731 fault while you sit at a stop? If not, can you then tap it to "1" and get it to launch normally without slippage?

 

[whyte]

Your overall symptoms don't make sense. To drive in 1st gear, you need the UD clutch to hold, along with the overrunning clutch (ORC) and/or the LR clutch (either one will work). The LR clutch must also hold in Reverse, so since your Reverse works OK we know the LR clutch works. LR should be applied at a dead stop in Drive (or manual "1"), so if trans is slipping then that would point to a bad UD clutch. But UD is also needed for 2nd and 3rd gears, so if UD were fried / bad, then trans should also slip in 2nd and 3rd.
So if you shut the truck off, clear the faults, then restart it, then shift into Drive (at a dead stop), does it set the P0731 fault while you sit at a stop? If not, can you then tap it to "1" and get it to launch normally without slippage?

i am unsure if the code will set at stop in drive gear after clearing code. its bizarre how it will upon clearing and especially while cold the truck will take off a short distance. *i can check after work. i appreciate your timely input cheers

 

[whyte]

Restart the engine, then shift to Drive, then tap it to "1" before you move the truck at all. It should then work OK. Once driving, tap it back to "1" manually (when coming to a stop) BEFORE it would normally downshift to 1st on its own.

upon re examining this approach lol you seem to be correct man1 will work. effects of running truck like this for awhile? sorry i was sure i had tried that numerous times i must have already had the slip happen cold as tits up here maybe my diagnostics were slacking

 

[whyte]

no code thrown when put in gear and brake applied. however manual 1 does not slip upon rexamination.

 

[transe]

no code thrown when put in gear and brake applied. however manual 1 does not slip upon rexamination.

OK, then I think the original diagnosis of a failed overrunning clutch is correct. You should be able to still drive it (using manual "1" at stops) until you can get it repaired.

 

[Bob4x4]

The common demonitor for failed over running clutch-stuck truck and lots of pedal