Torque converter unlocking

[xgrandprix]

My 04 GTP is having some torque converter issues. It is unlocking after about 15 to 20 miles of highway driving. It will not lock back in unless I pull over and park for awhile. I changed the fluid which didn't help. I had the lockup selonoid replaced and that didn't work. I also had the brake switch replaced. I have looked all over and can't find any info on this. Please help.

Thanks

[Scottydoggs]

sounds like your 4 th gear hub is wearing out. if you put it 3 rd gear and the rpm's stay the same, over dive is gone. it will slip in and out of o/d while its wearing out.

[xgrandprix]

No overdrive is working. The torque converter locks in in 3rd gear as well. It seems to be unlocking when the tranny temp gets somewhere around 186.

[16MustangVet]

If your 4th gear clutches are screwed up it will effect 3rd and 4th.... Ask me how I know... its a long sore subject at the moment lol. But yes sounds like the 4th hub or 4th clutches issue. Good news is you can do it while trans is in the car through the side cover, bad news its a pain in the ass to do.

Before anyone throws a fit yes it will effect 3rd and 4th if thirds shifting into mush it will act all goofy.

Search EASY by BillBoost and look at his transmission threads....

[Scottydoggs]

sounds like the pcs and tcc solenoids need to be changed, or the harness is bad. vet has no issues opening the side cover any more. done it how many times in how many weeks?

[16MustangVet]

twice in 3 weeks the 1 week I didn't I swapped a flex plate.... This coming weekend ill be doing a TQ convertor if it shows up in time.........

At least my trans isn't history!

[BillBoost37]

Personally.. I'd wait til it does it, don't turn the car off and have it scanned. Many trans codes don't illuminate the light and they reset with ignition off. If the PCM is keeping the TC from locking (sounds like it is) once a condition is met. You need to know what condition the pcm thinks it sees.

[Impala131]

Sounds remotely like what my old ass trans likes to do... I increased the TCC duty cycle table values in the PCM and it behaves much better, although not perfectly.

For a long-term fix, you probably need transmission work.