builtnotbought89'

I changed out the trans fluid & filter in my 1999 GC/WJ 4.7L Auto all wheel drive 138k miles... I change it & it ran fine that night, so I drove it to & from work the next day with no problems! Sooo today I start it up, back up, & put it in drive & the check engine light (CEL) comes on!!! Still shifting fine I drove it to work & use my shops scan tool & got
DTC (P1734- manufacturer specific powertrain malfunction)
So all I could do was clear the code & hope to god it doesn't come back! Well as my luck would have it I jump in the truck to go home, & gently shift it through all the gears only to get the CEL AGAIN!!! Then it started shifting hard when I put it in R, D, 1st, or 2nd also won't ingage tell about 1000-1500 rpm's. Then checkers scan tool read;
DTC's
P1734- 2c presure switch check (same code different summary?)
P0731- gear 1 incorrect ratio
Being as I don't have years on my belt with transmissions I could use all the help I can get??? Any & all educated input appricated!
Oh & I use Valvoline ATF+4 if that makes a diff.

Thanks in advance, & sorry for the LONG post!

builtnotbought89'

At least I always know I can fall back on the XJ! Ya she's got a bit of a drinkin problem, but she hasn't let me down yet!!!
Anyone got some input on the WJ???

builtnotbought89'

Any one got any ideas on this??? The dealer ship wants $98 just to diagnose it! They want $1900.00 for a remaned tranny, a wrecking yard wants $500 for 1 that has 90k miles!!!
Someones gotta have some ideas!

drakan1908

Have you looked around under there to see if a vaccum line or a wire got knocked off while you were changing the fluid? I find it hard to believe that a trans. would go that quick with a fluid change but I guess it could.

fantic238

Are u sure about the fluid type?

builtnotbought89'

Its actually common with mopar trannys, cause the ATF+4 has so much detergents! After doing my homework I've found the if it hasn't been changed EVERY 30k its not recomended to change it!!!
I'll take a look at all the connections & vacums, but the way its been acting it seems internal... Although vacum lines could be a possibility!

builtnotbought89'

Ya 100% sure, but that was my first thought also

fantic238

did you change the filter?

RENIXBEAST

If you dropped the pan and changed the filter I would look inside and see if any solenoid connections in the trans came apart??? If not try some Lucas I run it in everything.

builtnotbought89'

Yes I changes the filter, but I'm positive nothing inside was disturbed in the process. Thanks for all the replys keep them comming! The trans is such a dellicate system I think I'm just gonna take it to the dealer to get it diagnosed! I'll pay out my A#@, but I wouldn't trust anyone else to do it! Ya know...

rivercrazy

From what I've been told, if the old fluid was too old it will coat everything in the trans with a varnish and when you change it the new fluid will breakdown the varnish and it will clog up the trans. You might want to check out the new fluid really good and see if you can see anything in it. It might even be worth it to you to change it again (filter too) to get all that varnish out (maybe even power flush it).

Good luck man!

storm101

Speaking of these trans. I think its a 45RFE with the 99 GC 4.7 L.

I JUST did one of these last week (it was a 45RFE trans), there are TWO filters in that transmission, a bolt in type that looks normal and then a screw on type that looks similar to an oil filter.......did you change both (assuming its the same trans)?

The fluid smelled like burnt rubber on the way out, had a bit of slipping, we replaced it with fresh ATF4 and its been going good since.....

If you didnt change two filters, i would start your research there, it caught me off guard when i found that out...but there was two filters.....(and yes they are both in the pan)

HTH!

Also if youre unsure of the trans type, i do have a few pics of the gaskets to help identify what one it is.....(again I AM NOT sure if that was the ONLY trans with the 4.7 in 99)

builtnotbought89'

That's another thing I was wondering I did see that other filter that looked like ur regular oil filter? But couldn't twist it off with my hand, so I didn't want to mess it up! Plus with the fluid drained I didn't really have a ride back to the parts store! So what do ya think try replace both filters & fluid again???

storm101

Considering one was changed i would leave the new one be ( unless youre not wrried about saving a few$) and get more fluid and the other filter and give it another shot. F&f is still cheaper than the other options!

Plus with another fluid drop if there happened to be more crud loosened up, hopefully itll go with the fluid!

drakan1908

A buddy of mine owns a transmission shop and says this is true for all transmissions. He's tried to tell people this for years but they will insist that he change their fluid, next thing you know they are back raising hell that he ruined their transmissions. So he started making them sign a waiver about it before he will change the fluid.