Transmission Issue. Delayed Drive Engagement and Intermittent hard upshift to 2nd

[8UWITH6]

Transmission guru needed fellas please and thank you. In have a 4R75W with a 2 to 3 second delayed engagement to drive from park or reverse. No slipping, seems to shift fine initially. After driving for about 20 minutes of you come around a bend coasting down at about 20mph it hesitates and then kind of bangs into gear, like it's searching for a gear light throttle only. It's not violent but noticeable. The transmission has 140K not sure if was serviced before, pan has never been down. The fluid is full and it's not burnt but a little dark. I dropped the pan yesterday it was very clean, no debris or clutch dust. I changed the filter and put 5 quarts of fluid in it. I probably should have checked all the valve body bolts but didn't have time. It still has the delayed engagement and the hesitation has become more frequent. I haven't had a lot of time to research but I read valve body issue, dried up or damaged seals, or a forward clutch issue. I was just hoping someone has run into the same thing. The car is not modified it is completely stock. Any suggestions or thoughts would be helpful. Thank you.

More info the car drove fine for a few days with OD off but still had delayed drive engagement. It has now started slipping into drive we parked the car. I was going to drop the valve body and check for a cracked separator plate or check balls that are stuck or worn. I wouldn't think I would need to replace the entire valve body........... Any help would be great thanks.

[decipha]

What fluid type did you use? Merc V?
Have you verified the fluid level? Trans has to be hot (after an interstate run) and idling to check correct level.

screwy upshifts could be a broken accumulator spring which although its not too uncommon it is unlikely.

Im led to believe that both of your trans issues are related which I would think is a pressure issue. If you can verify hotter than normal trans temps that would lead me to believe the torque converter is at fault.

btw, if you have a trans thats been neglected and hasnt been serviced in 100k miles you shouldnt have changed the fluid as that usually causes them to fail.
If you have to top off a high miler I only recommend adding a bottle of lucas trans fix.

If it were me I'd toss a new converter with a bottle of additive along with fresh fluid and the lucas and hope for the best.

Unfortunately, Ia havent come across many vb issues.

[8UWITH6]

Correct fluid, correct level, etc. I am aware of correct service intervals. Once the trans engages into drive after the delay and slip then bangs to engage with overdrive off it performs flawlessly. That is until you have a light throttle condition where you are coasting down to around 20mph and step on the gas as stated above. I am struggling to understand why you would say torque converter or a broken accumulator spring. My symptoms have little or nothing to do with those components IMO. I appreciate the reply.

[Turbov6Bryan]

Where are the trans guys at?

[Turbov6Bryan]

Not really what i was trying to say.. Where are the transmission experts lol... I too say internal fluid leak. Put a pressure gauge on it bud.

[8UWITH6]

I was able to pull codes. Its got a transmission code for the output shaft circuit and a throttle actuator code. Btw this is an 05 CV Sport. I wonder how much input the electronic throttle body controls or talks to the transmissio? Hmmmm. Trans experts please step in. Not other trans types ��

[decipha]

if you have codes you need to fix that first before you can do any diagnostics

the oss is used to shift, if its not working correctly your shifts will be screwed up

throttle position is used for shift scheduling and tv pressure. If its not working correctly your trans shifting will be screwed up.

[Joe Walsh]

When I was younger, richer, and dumb... I bought a J modded valvebody for my Marauder's 4R70W.
Now that I'm older, poorer and still dumb...
I still have the very low mile OEM valvebody that I pulled out of the transmission.
What's something like that worth?

Sent from my Pixel 2 XL using Tapatalk

[8UWITH6]

Just to finalize this the forward clutch piston seal is probably toast. Even the smallest nick can cause a pressure leak. This means the clutch will apply, but may leak pressure slowly and cause the clutch to burn. The forward clutch is applied once you put the gear selector in Drive and it stays applied in 1st, 2nd and 3rd gear, so it has to keep fluid pressure otherwise it starts to slip. The separator plate cracked where the 2-3 servo cover pushes on the plate. This causes Forward clutch pressure to bleed over to the direct clutch passage. I replace the separator plate with the Superior Tuff plate part # K092 and it made no difference. Rebuild time.