[427-6spd]

My transmission is shifting out of gear, into what seems like neutral, in any gear at any time. It started doing it while i was going 80 mph on the interstate on a down grade. At that time the tranny was only shifting out of 4th in to nothing, but now about 100 miles later it is shifting into nuetral out of any gear and it doesnt seem to depend on throtle position. Codes that i have pulled so far are po734, po735, p1721, p0748, and pu1016 the truck has an air intake, edge juice, and 4" exaust. The previus owner had the tranny rebuilt just under 15,ooo ago, and he told me he had the nsru replaced on the truck so i am running out of options i guess. Thanks for any help that can be given ~justin

 

[Brayden]

P0734 and P0735 are steady state slip codes for 4th and 5th gears respectively. I'd say you've burned up the C2 clutches. The P1721 is also a P0776 which is a dead ringer for burnt C2's. It will usually occur on the 3-4 upshift.

It should limp to 3rd gear on a 3-4 upshift failure though not neutral.

The P0748 though is an electrical code.. You should chase that down first. It may be causing some of your problems.

If the trans fluid smells burnt though, I'd guarantee the C2's are burnt.

Fill out your signature so we have more information about you and your truck.

Let me know if you need any trans work done.

Brayden

 

[427-6spd]

I think the dealer is crazy

I took in my truck to the local chevy dealership to have it checked out and what they came up with is a bad transfer case.

Which in a way makes sense because if the transfercas is slipping it could give me the codes that ive been getting for improper gear ratios for all gears except reverse.

what do you guys think?

 

[Brayden]

Transfer case can't slip.. there are no clutches in it to slip. You could break a chain, but you'd know it

You probably do have a hole in the T-case where the pump rubs through it.

So the dealer may be right, your t-case is bad..

But your trans doesn't throw codes like that for no reason.

A P0776 and a P0735 mean that your trans is probably fried. C2 clutches. Does it limp when you roll on it in 5th gear?

Let us know.

Brayden

 

[Machinator]

Remember that the transmission gets the output speed used to calculate the gear ratios from the speed sensor in the T-case. If it's giving the wrong info, that could also result in incorrect gear ratios codes.

 

[Brayden]

True Mac.. True.. but that P0776 and P0735 just seem to scream burnt C2's...IMO

Hope he chimes in when he gets it figured out.

 

[parrothead68]

just going thru this myself, the transfer case is junk, in my truck. it would slip into neutral for no reason at all. the bearings in the transfer case are gone and wobbled out the housing and let the shaft slip back and forth which i think machinator said would cause the codes to be thrown. that is what is happening with mine. i thought they were full of crap when they told be the transfer case was causing the trans problem.

 

[stony1212]

Truck won start on its own, and trans wontshift, code p0776

My 03 1 ton has been haveing trans trouble for a frw years now. When I push hard it slips bad, now its kicking code p0776. Ive cleared it lots but it comes every trip. Also it wont start 3/4 of the time. Ive took it in several times to the dealer but they say nothings wrong. and now thr trans is going nutsand wont shift into over drive. Its got 80000 miles. Is rhere any type of warrenty on the tranny, and #2 Just out of the blue it wouldnt start. It wont show a code on the non-start. Injectors are the main reasonfrom what Ive gathered. I need some strong advice on how to get it running up to snuff. also what should I do to make the trans take the extra power w- jamming gears or slipping.
Thank you for your ino
Stony

 

[Brayden]

Where are you located.. Try the primer button on the fuel filter housing when it won't start. IF that helps it start, then you have a fuel line leaking down.

The trans needs rebuilt. How much power are you running?

 

[427-6spd]

Hey guys finally got my truck fixed and back so I thought I should update you. I took the truck back to the shop that originally rebuilt the tranny and t-case about 13000 miles ago. They pulled the drain plug on the t-case, and guess what? No Fluid. I guess I should of checked it but I had only owned the truck for a little less then a month when I started having problems and there were no new leaks on my driveway. Also I had to replace a faulty fuel level sensor and I didnt notice any oil on the bottom of the truck anywhere, so where the fluid went I dont know.

Anyhow what the shop came up with was a broken shift fork in the t-case, they fixed it and fixed all that was damaged due to the lack of fluid. They also went through the tranny and found no problems so I guess the t-case really was the problem.

Thanks for all your help,

Justin