Southerner

Okay, let me do my best to describe this for y'all. I drove my truck about a thousand miles this week on a long trip and everything was working great. I got home then went to run some errands. On my way back to the house I started having transmission problems. The issues are as follows:

VERY hard downshifting when in the 30-50 mph range. Completely out of the ordinary and started very suddenly.

When accelerating from a stop the truck will miss and it revs high then suddenly catches and starts going. This is what worries me the most.

Like I said, this started very suddenly. So far I have replaced the transmission fluid filter and flushed the fluid. I filled to the center of the cold fill range made sure to cycle through all the gears in the driveway and all that jazz. Took it for a drive and no changes. If there is already a thread on this issue (I haven't found one) then point me in that direction. If not, please give me some ideas on how to fix this without replacing the transmission!

Dynamic

As a zero dollar idea. Perhaps your computer strategy is having a hard time adapting to change in driving style, long trip vs in town.

Disconnect your battery for 15 minutes and try and start your engine. This will drain all the power from your computer and it will reset the strategy to stock on boot. Reconnect the power and see if the problem still occurs.

Southerner

That would be nice. I'm hoping that it's something small. It was such a sudden change. Working perfectly one minute and then a total POS the next. I'll try your idea in the morning and post the results

vintageman

Just remember to bring it to operating temps and then do the battery relearn process posted in the ever so helpful "Stop, read here first" sticky thread. It will help ensure that the idle is good when you are coming to a stop and so forth to prevent stalling from your pcm trying to relearn your driving habits. Also make sure that you check your trans fluid when at operating temps and the transmission is in Park, not neutral. Checking it in neutral will give you about an inch more fluid read on the dipstick. When you changed your fluid, how much did you add, I just changed mine a couple weeks ago and it took about 5 1/2 quarts to get to the right level.
Good luck
Tom

08silverbullet

I coil going bad can make it feel like the transmission is acting up. Mine jerks around 45-50 then it's fine I have 8 new msd street fire cop's just need tip put them in

Southerner

It's definitely not the COP's this time. Trust me, I've had plenty of issues with those already. This is a transmission issue without a doubt. Unless it's a computer issue which I hadn't considered until y'all mentioned it. I'm going to try the battery relearn thing but I doubt it will help. I'll let y'all know

Southerner

The computer reset and battery relearn were ineffective. When I changed the fluid I pumped out all 13.9 quarts and replaced with new fluid. The fluid didn't look too bad so that clearly isn't the issue. Something mechanical is going on. I'm thinking maybe replace the accumulator spring and shifting solenoid? It cycles through the gears fine. It's only on downshifts and when I first take off that I have problems. Downshifts seem slow and labored and when I take off there's a high rev and then a big bump as the truck starts to accelerate.

Edit: forgot to add that this only starts to happen after the transmission has warmed up. It works flawlessly until it's hot.

Tazzfx

What about the overdrive "servo" clip? It has been known to break and cause a ton of problems. I actually looked it up on YouTube, and it might just be your issue. Take a look and let me know. The clip gets brittle, breaks apart in the trans valve body.

cscott900

^^^^ yes, check that servo clip. It's kind of a pain as you have to drop the valve body. If that turns out to be it, make sure you clean the valve body well because pieces of that clip can lodged in multiple places.

ArthurA

Also, an issue I had was the fuel sender was failing affecting the ECM to pull back when the fuel was not sending. Replaced it and that solved the issue instantly. The mechanic can check that pretty quickly.