• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Tranny issue

P

paedbo

New member
2001 gt

I obviously know my tranny is screwed but trying to figure out what exactly could be wrong with it.

I searched on the forum and google and couldnt find anything exactly like my situation.


At a stop sign, I go to take off and a huge bang underneath the hood. I let off the gas and then try hitting it again and realize the car takes off in second gear. Luckily i was only a 1/4 mile from home. I get home and I go to try reverse it doesnt work, So i put it in neutral so i can try to push the car out of my driveway but it will not move backwards it feels like its binding up. I shut the car off in neutral and it easily was pushed backwards out of the driveway. In the street I tried to shift down to 1. The car will not move in 1st either. I'm trying to figure out if maybe this is a broken band issue but i am uncertain exactly how the 4t65e outside of the shift solenoids and the pcs exactly works.

Anyone have any ideas? I'm going to try to see if i can pull any P codes later tonight.

Thanks.
 


sounds like a tranny swap or a rebuild. when things let go in a tranny you may as well just replace old parts for new ones. there is no point in trying to save whats left.
 
well thats why im trying to see if maybe its a band, Ive pulled the tranny partially apart last year to fix the no OD issue. I dont have a problem pulling the rest of the guts out but i wouldnt be able to replace teflon seals and stuff like that so a swap is probably the only way to go. I just dont want to put crap back in !
 
the only way to know what broke is to pull everything out but if you going that far may as well have new parts or a known working one.
 
Ok so I took it out for a drive heres what I found. P1810. Ill start with reverse, car moves no where can feel some kind of a shift happening. Engine will only rev to 3k rpm because of the tc. Put the car in neutral and it will drive starting in second gear it will shift to third but couldnt get up fast enough to see if od would work. Same with D and 3 as neutral. 1 and 2 if I rev to 2k it will start to try to move barely but as soon as I let go of throttle it acts as if im hitting the brakes. When i went to shut it down i put it in park and tried to rev the engine and i felt the car lurch until the pawl engaged and realized i cant rev the engine over 3k there either. Could the switches be causing fault to not know what gear im in and having forward and reverse engaged at the same time?
 


Sounds a lot like a broken forward band.

As far as not being able to rev over 3k... I think that's right around where the rev limiter is for P/N, or just a little higher.
 
Well the car will drive in neutral starting from second. And it lurches in park. I have no way of checking the line pressure. I read something about back probing the tranny harness but have yet to find what pins i need to probe. Wondering if a seal blew causing some kind of max adapt and pressure is so low that its causing all this other crap through the pressure manifold.
 
I know this post is old but I finally dropped the sub frame and pulled my tranny apart. Planetarys destroyed due to a bad input seal banging the car into gear while falling into neutral at lights. The sun gear also suffered damage as the front/rear planets and sun gear are all stuck together in the mayhem. $30 sourced out on ebay for a complete set. Rebuild and off I should go.
 
I got tired of taking pictures, I only took pics as far as putting in the stove pipe. I was wrong in the beginning as the tranny was actually starting off in 3rd. 3rd gear is a 1 to 1 ratio Since the planetarys and input sun were all jammed together. This explains why she would drive in 3rd gear while the selector was in Neutral. according to the 4t65e repair manual the input is applied but not effective in every selector position , However since the planetarys were locked up is the reason it would move in Neutral. Also the reason it would bind up in reverse was because the input was trying to turn the planetary carrier forward ( because they are jammed) and the reverse reaction drum was trying to hold the input carrier still at the same time. All this caused by the bad lip seal on the input drum ( which was repaired also).

20160927_154035_resized.jpg
20160930_112608_resized.jpg
20160930_120414_resized.jpg
20160930_121220_resized.jpg
20160930_121521_resized.jpg
 
Last edited:


You must log in or register to reply here.
Back
Top