Converter slipping after trans flush.... WTF?

**Skillet** · 03-23-2012

Got a 2002 GTP all unmolested bone stock.... This is my commuter car to work that's been babied, I just did $2700 in maintainence and after a trans flush I am noticing some converter slippage. Normal driving it doesn't do it. Seems to be only when taking off going up hill and its when it locks going into drive.... If you let off the throttle then get back in it it quits..... I've owned the car since 40,000 and it has 159,000 on it now.... Like I said Ive never even had the pedal to the floor..... Any idea here? I'm gonna call the shop in the morning and ask if dextron 3 was put back in it..... Any sensors on the trans that maybe could have something to do with this?

**FordMan77** · 03-25-2012

Hopefully the flush didn't dislodge something and move it to another part of the trans. thus causing the issue. I know a lot of times if the trans is flushed it can cause issues. I would think that taking off on a hill the converter is out of the picture as far as locking since (and I can be wrong here) the converter only locks in 3rd and OD. If you have having issues from a dead stop like that I would think more of a forward band application issue. With you letting off the throttle a bit then getting back into it, it makes me think that whatever is sticking and not allowing full engagement finally catches when you get back on it. Pressure drop when off the throttle then a rise when you get back on it. Kinda like kicking it into place.

That's just me thinking outloud though. I am by no means a 4T65E expert. Just seen a lot of strange things, lol...

How does the fluid look? Nice and red? Is it full? I would check the level and be sure they filled it properly. Just get it fully hot, park on a level surface and leave it running to check it.

**Scottydoggs** · 03-25-2012

had you ever serviced your trans before this trans flush?

if not i'd say your trans is now toast. a full flush with those miles and never been serviced before is a recipe for disaster.

if your lucky you could suck out a quart of fluid, and dump some trans medic stuff. and maybe it will hold better. i think people have had good results with the lucas products.

**dsmuts** · 03-25-2012

I'd try some lucas if nothing else. It's some good stuff. I've used it in about every vehicle I've owned and it's "fixed" some I thought the trans was dead in.

**SlowNA06** · 03-25-2012

Trans needs a reset for new fluid. Unplug the battery for a while.

**dsmuts** · 03-25-2012

^^^I've never heard of anything like that before.

**Scottydoggs** · 03-25-2012

that makes two of us.

when i had my last 2 new pickups i had the transmissions flushed every 30,000 miles from day one as i owned them from new, never reset a thing.

most lube shops will not touch a trans, flush wise if it has high mileage and no service history. i saw at the shop i went to (my friend was the manager) guy wanted a trans flush, they check the miles, tell him they dont recommend doing the service, but the guy wants it done, so they have him sign a form releasing them from liability if the trans fails afterwards, and he signs it, did the flush, then called a tow truck. the look on the guys face was priceless lol, he had no gears at all just engine rpm's.

**z3r0** · 03-25-2012

That's how ui blew up the tranny in the ram. But a year later after I fried the trans, had the burnt fluid flushed, then drove it for another year before the torque convert exploded and clogged the trans cooler and blew up the tranny.

Android Fire

**tc300** · 03-26-2012

Originally Posted by slowna06

trans needs a reset for new fluid. Unplug the battery for a while.

w t f...??!!?!!!

**boostedcompg** · 03-26-2012

Originally Posted by SlowNA06

Trans needs a reset for new fluid. Unplug the battery for a while.

god i hope this was sarcastic

**Pure2sin** · 03-26-2012

I have always heard to never "flush" a transmission with high miles and to only drop the pan and change the filter and fill it up with whatever fluid it lost.

Did you have the filter replaced and check/clean the magnet off?

**Ice Blue La Crosse** · 03-26-2012

tranny re-set

**Pure2sin** · 03-26-2012

Actually if you want to be technical the PCM does reset itself. So I can see what he is saying as far as the trans. Is it necessary when doing a flush no.

**BillBoost37** · 03-26-2012

What he's suggesting is resetting the learned transmission adaptive settings. That way instead of slowly relearning..it may correct pressures etc faster.

This sounds like the friction material that was suspended in the fluid was helping the clutches or bands engage and hold. Not sure when it's happening as I don't understand your mention of "when it locks in drive". However I would start with a bottle of Lucas stop slip and see if that and a pcm reset helps.

**SlowNA06** · 03-26-2012

Sorry for confusion. Was posting on the fly.

**Skillet** · 03-27-2012

The flush was done by a reputiable shop around here known for doing excellent work..... I've had two done by them before, one on a 66 lincoln with 100,000 miles and the other on my 2009 6.4L Ford with 20,000 on it only cause its a sled puller.... Both worked out just fine...... The snap on transmission fluid exchange machine, doesn't apply pressure at all . It pumps in whatever comes out . 1 quart at a time .. and takes a couple hours.... They did also drop the pan and change the filter..... I like billboost37's reply... He's on to something stating there was friction material suspended in the fluid .................. Its not the trans slipping , its the converter slipping upon lockup............ It only does it around 40-50 mph....... It shifts fine from a stop when it starts is 1st gear, shifting to 2nd, then drive.... around 40 or 50 mph the converter locks up and that's when you feel it shuddering/slipping..... You can look at the tach and see it jumping up and down a few hundred rpm's rapidly.... If i let off the throttle and get back in it , it completely stops and goes away.... Then it won't do it for a couple days....... I 99% sure its the converter......... Are these transmissions in these cars capable of throwing a code ? Like could I take it to GM and see if its throwing a code for converter slippage?

**Skillet** · 03-27-2012

Forget this part................ Worst case scenario, what does a 4R65E bone stock rebuild go for ? Should I try trans x or lucas trans treatment first? While it was in there, I had new cv shafts installed, 4 new quick struts, new ball joints, new brakes n rotors all the way around, new rear parking brake assembly from GM, Man, drives like a brand new car lol

**BillBoost37** · 03-27-2012

I'm changing my view with the newest info you posted. I suppose your converter clutch could be doing that, however it's more common for tune up related or TPS/MAF to cause that rpm oscillation.

**Skillet** · 03-27-2012

I'm pretty sure the converter locks in drive on these cars, am I wrong and it locks in overdrive though? I know the GM 700R4 waits till OD to lock up

**BillBoost37** · 03-27-2012

Depending on the year and lockup strategy, it's not a 100% lock. Which leads us back to TCC oscillation. TripleEdgePerformance has a write up about what can cause it. As well ignition commonly causes it. I would be checking and replacing my plugs/wires before I invested in a new converter/trans.