03 5AT won't shift up
 

Search didn't turn up anything, so here's my problem. Starting a couple of days ago, for some reason, usually going up hills (not even big ones), my G won't shift up. This is in the D position, and I have to switch it over to manumatic and manually shift up in order for it to actually follow through..

Seems like it usually occurs in 3rd and 4th. Right when I switch over it catches and shifts up though

Any thoughts? Has this happened to anyone else..?

Thanks. I'm hoping it's not anything too serious.. :icon43:

Happened to me in December. I had to get a new trans. Have you ever changed your fluid? If not try that first and do it fast so you don't have to get a new trans too. Good luck

I just got the car passed to me about a month ago so I'm ont sure about the last time we got the fluid changed. Hopefully thats all it needs, a new transmission would be a pain.

Any update?

I was in Colorado over the weekend so nothing has been done yet. I'm going to try and take it by a shop tomorrow to get the trans fluid checked

Good luck

good luck, this scares the hell out of me as i'm approaching the 150k barrier

Used transmission is 500 with about 50—75K

5150DS mentioned on a different thread that when you change out the transmission fluid.. you shouldn't do a complete flush right away especially if you've been using the same transmission fluid for awhile due to the transmission becoming used to wear materials that uses them for friction in the clutch packs. A sudden change of all the fluid can result in slipping. This means time for a new trans. The slow change in fluid should prevent the slipping.

That makes sense though and it kind of shows too because people who have done a transmission flush right as they run into a problem like that have usually ended up changing out their transmission a short time later.

I'm in for updates. Good luck man

The only time mine doesn't shift is going into fifth when its really cold like below 15f

Even after the engine and trans has warmed up to operating temp?

That's not too bad, for some reason I thought it would be like 1900 or something..

So in other words I shouldn't get a complete flush? Just a partial?

I'm in TN and it's been around 35-60F lately, which seems like it wouldn't be cold enough...I guess you never know though :dunno:

Yep! Usually only happens when going up hills...I guess when load increases. I'll start edging more on the throttle to compensate, but the RPMs just steadily keep rising with no catch. If I give the throttle more of a jab..a more abrupt input rather than a steady one..the trans actually catches but kind of abruptly with a bit of a jolt

Yes, a partial flush sounds like it'd be your best bet.

Here's something you can try. My wife's '05 Maxima trans stated slipping on the 2 to 3 shift. It would hesitate for half a sec. then bang into 3rd. This is with trans flushes at 36K and 78K miles. I added a bottle of Lucas Transmission Fix and it's about 90% better with less than 100 miles after the add. It might be just a band aid approach but it only cost $10.