Put my 2001, 47re with 2nd gear lock up to the test this past weekend. My rig with 5r weighs 17,600 lb. I navigated parts of the 6% Grapevine canyon on I-5. The trans worked flawlessly. On grades I would lock into 2nd push her up to 2000 rpm and flip the torque converter lockup switch. The oil would heat to 210f while pushing up to 2000rpm. After lockup trans oil cooled to 180, eng temp, and stay there. The grade and load took all the 235hp at 2700rpm I had with skinny pedal flat on the floor. Going down same grades decelerating, I had the same result. Just love that mod. Strongly endorse the 2nd gear lock up mod.-

Hi John, I am down the road from you in Agua Dulce, I came up the Grape Vine with my 5th wheel and the outside temp was over 100 degrees outside and I stopped at top to cool the trans down. I have a DTT trans.  and added a cooler under the truck. We put a sw. for a lock up on my boys truck and he used it. Might have to add one to my truck. BUT my real question is where are you measuring the the temp of the trans. Where is your trans temp sensor. I get a lower reading with the laser temp. gun.Ed 

My temp sender is in the line going to the cooler. ( Hottest oil in the system)  I removed the factory sender and installed the sender in that port. My trans shop ( Valco, in Littlerock) plugged a port in the valve body plus the switch. Outside temp was also 100f 

What did they use to plug the port? I have seen where they used JB weld but that kinda makes me nervous. I just wonder if the oil and the repeated heat cycles would ever break it loose.

Cleaned & scuffed well, it is reported to hold just fine.

 

Ed

I know very little on the subject.....

Is it possible to damage a trans if you forget to turn it off at the right time or say turn it on at to low of rpms?

I would suggest having the proper supporting mods (Billet input, upgraded clutch packs & triple disk torque convertor) if using it racing.

 

Ed

The shop that did my mod has a mill. they drilled the passage slightly larger than the width of the channel. Then made a aluminum pin that blocked the passage. Over kill probably. The procedure is detailed in the Cummins Forum. I printed the Cummins forum article and took it to the trans shop. They did it reluctantly. Yes it can break thing if used improperly. I have already failed to switch it out before shifting up. Up shift with a locked converter is very hard.

I would be much more comfortable with the way your shop did it than using JB weld.

What did they use to plug the port? I have seen where they used JB weld but that kinda makes me nervous. I just wonder if the oil and the repeated heat cycles would ever break it loose.

Sounds like a blood clot and stroke you're describing.

Have you seen the passage where the blockage is required? I doubt jb weld would be going anywhere wrong.