mikie1234

I hate to ask this but I guess you will never learn if you do not ask. WHAT'S converter lock. When I let off yhe throttle say comming to a light the rpm's will drop around 900. Is that normal? Thank's for all the help. I have learned alot here. I have a 96 ram 2500 long bed 4X2 5.9 cummins all stock.

SuperGewl

On most of the auto's the Torque Converter usually doesn't lock up until you are past about 45mph. If you are coming to a light it will usually unlock as you are stopping but you won't notice it. Dropping to 900rpms is normal when slowing down coming to a light.

Flashdancr

Go to search type in; Confused Tranny Question
This thread helped me understand lockup.

Search is a good place to look for answers. Just type in what you want to learn about, a lot of good info there. If you can’t find it in search don't be afraid to ask questions even if you think they are dumb.
These guys are great and will help you all they can.

Glad to have you with us.

j-fox

The torque converter has a lock-up clutch in it. Under the right conditions it is told to lock.
The factory has a desire to do it one way, while each aftermarket trans company has their own.
A fairly high percent of trucks that do lock it during shifts are getting to spend more money to re--fix the trans. The shafts break. Not all though , some are using a better supply of luck than others. The other idea is to lock it and keep it locked for an exhaust brake to slow the vehicle by engine braking. If you want to do that GET A MANUAL TRANS.
This is a hot topic and will get negative comments.
My opinion is to keep the auto in an auto mode unless you are planning to abuse it and repair it often. I like mine best in the truck right behind the Cummins, not on the bench or thinning my wallet.

dssimecek

Hmmm
My 2002 3500 does that also. I have option "DHAP Lock-Up Torque Converter". Yet I will be mobolating down the intersate at 70 mph, and if I let up on the loud pedal the RMP's do drop down.
An injector shop that, does Pacbrakes. told me I would not need to add anything to make the exhust brake work.

j-fox

If you use an exhaust brake with the auto, the problem is the no throttle situation. When you lift the throttle the pressure goes down in the trans and this can allow it to slip the clutches.
Something must be modded to save the trans. There are ways to do it. I am not familar with them, other than the adds.

Kyle Graham

Running exhaust brake on an auto with out a torqueconvertor controller is kind of a pain you have to manually downshift the tranny flip on brake to get results and on a dodge line pressure is controlled through accelerator pedal. Bd diesel performance makes a product called the towloc which controls the torqueconvertor lockup when exhaust brake is activated. Another cool product is a pressure lock which is a pneumatic ram that controls line pressure on transmission instead of linkage from accelerator pedal

dalton4

Mikie1234, the converter will unlock if the throttle is lifted to idle position and you can tell by the rpm dropping to idle range.

Using the manual lockup switch (mystery switch) can do harm if not used correctly. However, like other things, one should understand the designed shifting of the tranny, line pressures and how the switch can be used to achive desired results without placing unwarranted stress on the tranny. Using the mystery switch requires that the user keeps his/her mind on the task in play. With the valve body mods by Goerend, and using the mystery switch, I can lock the tranny in all forward gears. When this type driving is require I do shifts unlocked and relock after completeing shift. The tranny is then being used mainly like a straight shift. Staying locked in the lower gears eliminates the tranny heat building problem and puts the power to the ground.

bluepp

Good info Dalton, but to explane Micky1234 question just what torque con. lockup is - Micky ,pickture it like this. 2 fans faceing each other. run one fan it turns the second fan,but never as fast as the running fan because of the air slippage. Now the running fan is hooked to the motor, the second or driven fan is hooked to the trans., with oil in between instead of air. This whole fan setup is a torque connverter. As the oil whips from one fan to the other the oil gets hot. The bigger the speed difference between the two fans the more the oil whips and the hotter the oil gets. Now between these two fans there is a clutch disk. at a predetermend time this clutch disk will LOCKUP the two fans together so they both turn the same Now you have no more oil whip and thus no more heat buildup from the oil whip. You also have both the motor and trans now turning same rpm. Just like a manual trans, with the clutch engaged . The problem is in the fact that this lockup will ocure at times when the motor is pulling hard and the lockup clutch must pull all the torque of this cummins down to the speed of the trans fan. This burns the torque conn. clutch out and the junk then goes through the rest of trans ruining the whole thing. The secret is to allow the shift to take place under little or light throttle.
Understanding all this its easy to see the torque conn. clutch is the weakest link in our auto trans with this cummins. If you learn to let it get into lockup without much throttle it'll last much much longer . If you want to make it better with aftermarket concider this.
Theres 34 sq. in clutch facing on your dodge torque converter clutch. You can buy a ATS torque converter that has 117 square inches of clutch surfice, It has 3 clutch disks instead of one. It only cost $1300.00 !! but it'll fix the problem. And theres many other good Co that can improve the unit also and maybe for less money.

dalton4

Bluepp, nice explanation on the converter and lockup. Time for me to get new glasses. Mikie's main question started with "what's" in caps and I blew right over it.

Flashdancr

Good explanation Bluepp! By the way what kind of material is the toque con. clutch made of. Wouldn't be brass in color would it?

mikie1234

Thank you for all the info. I think I'll go with the suggestion that getting a T/C with three clutches instead of the one just makes since. Rather to spend $1300.00 + installation now than around $4000.00 later for a tranny. Thanks

bluepp

Micky 1234 Check out the ATS Deisel truck site. they can work your trans over doing stages. Like you can just do the torque conn. Or you can do the conn. and valve body ETC . I think they have 5 stages. 5th stage being for HIGH hp raceing purposes. Stage 4 gives you a complete trans upgraded rebuild for towing , with connverter lockup in all 4 GEARS on a 47re trans. $5500.00 installed at there plant in Arora,Colo. a suburb of Denver. ATS -- and BD are two good ones ,I'm sure theres more, I preffer ATS Tripelok, but they are expencive.
www.ATSdiesel.com www.dieselperfomance.com