Transmission Trouble: Automatic Not Shifting to 5th Gear

I think what he’s talking about when he says “laboring” is the higher rpm’s above 50-55 mph that he is noticing. Since this transmission starts locking up in 2nd gear it wont be as noticible of a lockup but with 500-1000 rpm difference, he is losing a gear, not TCC. I dont remember what kind of Dodge you have but if you have a 604 transmission you DO have partial lockup. You will notice the unlocking because the 604 will not “partially” unlock they only partially lock.

transman

I agree that he is talking about higher RPMs as laboring. And he might just be losing OD. What do you mean by “partial lockup”? Does that mean the clutch is slipping some? I am almost sure mine doesn’t lock up in 2nd gear.

On the 604 transmission, Chrysler incorporated a system within the TCM called EMCC (Electronic Modulated Converter Clutch) If I recall off hand, it started on the 604’s in 1993. I might be wrong on the year though. It allows the converter clutch to start locking up as early as 2nd gear. Now, the only time it will actually start locking up in 2nd is when the trans temp starts getting higher (around 180-190 degrees) otherwise lockup will start in 3rd gear and fully lockup in O/D. Now, when you ask about the slipping, partial lockup actually causes LESS slipping allowing earlier cooling and better fuel mileage.

transman

In order for the TCC to lock up in 2nd gear, would one have to have the vehicle locked in 2nd gear? If in drive would not the transmission shift on up to 3rd instead of the converter locking up?

No. Remember now, this is a “Partial” lockup. The converter clutch begins to lockup after the transmission shifts to 2nd. It wont start to lockup in 2nd unless the trans temp reaches a certain temperature otherwise it will begin its partial lockup in 3rd gear and become fully locked up in O/D. Its electronically modulated so its easing itself into full lockup.

transman

Transman, if I have the OD locked out my transmission will “lockup” in 3rd gear not “partial lockup”. If in OD it locks up in OD or 4th gear. However mine is a 96 with a V8.

Yes, if you have a 604 transmission, and you lock out O/D by way of switch inside engine compartment, you will have full lockup in third gear. UNLESS, of course the transmission is running too hot for some reason then the trans will start to lockup in 2nd and fully lockup in 3rd. But under normal circumstances, you will fully lockup in 3rd.

transman

I never knew about the lockup in 2nd gear, since it has never done it. I don’t think my manual mentions it but I read that it might. Did the OP ever decide what his problem was?

I wonder if he ever got your car fixed cause am having thes same problem with my venza2009 the engine revs at higher rpm when it gets to5th gear