transmission disengages after 30 seconds
 

ok, let me start off by saying that i had my trans rebuilt about 50k miles ago, in 2003. about 6 months to a year later i began getting the P1870 code, and i had an intermittent problem (more often than not) of my car not being able to go into overdrive. well, i noticed today on my way home from school that the check engine light had turned off! i dont know if that was just a coincidence, and if the code i used to have has anything to do with this, but i thought id share that info anyways.

it was driving great, and i was able to get into overdrive on the freeway. then i hit traffic. im sitting there, stop and go, and then the traffic picks up and i give my car gas. the engine revs but im not going anywhere. i made sure i was still in drive, because it felt like i was in neutral. so i shut the car off and turned it back on, and put it back in drive (from neutral) and it worked. then about 30 seconds later it happened again. so i put it in neutral, shut it off, back on, put it in drive, and this cycle kept happening the whole way home. i had to limp the car home going about 40 on the freeway. (i only live about 10 miles from school). so i get home FINALLY. and check the fluid, its full, but it has a brown color. and definitely doesnt smell sweet like it should. im going to change the fluid and filter tomorrow, but do you think just that will fix whatever this problem is? ive never had anything like this happen before. i noticed that the longer i had the car shut off, the more time i could give it gas before the transmission would disengage from the engine. would this be an indication of the torque converter going out? like i said, my check engine light is OFF. are there any tranny additives i could use that might fix the problem? what type of tranny fluid should i use, any recommendations? thanks guys.

Sorry to say it sounds like your transmission is in need of another rebuild. Although that is short mileage and time for a rebuild.

Try changing the filter and fluid, consider Lucas trans additive. Check your owners manual on the fluid spec. I think it's dex 3 or higher

If you are going to service the trans, I recommend that you use the products from Lubeguard.
http://www.lubegard.com/automotive/index_trans.html

Their stuff works great and it is even recommended by auto manufacturers in some of their TSB's.
Use their flush for both the trans cooler and transmissions and then add a new filter with high quality ATF and add the Lubeguard additive and Shudder Fix additive.

well i can drive the car for short distances, like last night after i got home i was able to move my car into the driveway with no problem. it never did that before when the trans went out. it doesnt feel like theres anything thats broken, it just disengages.. however you're probably right. ill take it to a trans shop this weekend and see what they have to say.

trns
 

try checking the trans shift link adjustment first.
It could be slightly off. Procedure in the book.

i tried that, its definitely not the transmission shift link. would changing the fluid have any affect at all? i couldnt find any lube guard stuff at kragen, will that really help out or would i be trhowing away money?

Keith, what does your fluid look and smell like? This can be either major slipping of the TC, or it might be the TCC solonoid that has entirely failed and cannot regulate the TC. This last idea seems most logical since you cycle the ignition and it resets. But I'd still like to know what the fluid looks and smells like. With too much slip to be able to regulate, the PCM may be commanding the TCC solonoid to a 0% duty cycle state.

the fluid is light brown. its not super super dark, its just not pink anymore. i just never changed it when i got the transmission done, and ive been meaning to, but well i guess this is what i get for being lazy. it doesnt smell burned, it still has a little sweet smell to it. well i just drove it around the block to see if i could get it to disengage again. its been sitting there for the past week with the battery disconnected. so i hooked it up and it drove around the block fine, no slip at all. i guess i could just slap a for sale sign on it, or change the fluid and keep it, haha. but i experienced the transmission problem on the freeway so maybe it has to be warmed up in order for the tranny to disengage. on my way back to my house i gave it a little gas and let it rev to about 3000, but it seemed to drive fine. im going to do the fluid and filter sometime this week. are there any pointers for doing it? i dont have a haynes manual so i dont know if theres anything special i need to do besides unbolting the pan. how much fluid should i buy?

willren, im keeping my fingers crossed that its just a solenoid that needs replacing, as that sounds like it'd be much easier than buying a new torque converter. let me know what you think! thanks.

My advice would be to get it professionally flushed. Should run you between 50 and 100 bones.

On a last ditch effort, you can change the filter, fluid, selenoids and add a bottle of LubeGuard.

You can purchase a complete selenoid kit for the 4T60E transmission made by Fitzall.
http://www.teckpak-fitzall.com/teckf...s/MS_4T60E.jpg

Although you have to use some elbow grease to reach the selenoids, the instructions are straight forward. The pdf file for the instructions are as follows:

http://www.teckpak-fitzall.com/teckf...ts/ms4t60e.pdf

Also, get the GM filter kit and use quality trans fluid along with a bottle of LubeGuard.

After the trans work is complete and prior to starting the car, adjust the TPS and erase the codes.