Problem is with no lockup cruising for any length of time at highway speeds will overheat the tranny.
Better to fix the tranny right rather than get bigger tires. If the tranny overheats much you'll be buying a new one before long anyways.

 

ok...not to hijack this thread or anything, but it seems there are some pretty smart fellors following it!!

I just put a 47rh into my 92 cummins... What is the best way to hook up the od and the lock up.. I've read about the swith method, a little on governor pressure. But, I was talking with a guy and he was telling me he did not like how the tranny shifted off governor pressure, he said that he has a module that controls it?? My goals with the truck are to throw some power to it and still have my wife be able to drive it without having to flip switches all the time... Any input would be greatly appreciated..

 

That trick fixed my truck last year, I gave up on factory cooler lines (after 3 breaking) and temp swithes (3 malfuntioning) I now have a braided hydraulic line for a cooler line and a 1k ome resistor in the trans temp holder. Haven't had anymore problems out of mine since then.

 

On the 47rh 1-2-3 shifts are controlled off gov pressure. I don't know how'd you change the shift points. There is a PCM that controls the 2 wires for TQ lockup and shift from 3-4. You can wire them directly up to switches.

In my case, I never get to 4 even with a switch on the wire, so I am stuck at 3. I am running 37's now with 3.55 gears. By my calculations I have about the same ratio as a truck running 4.10's, a manual tranny, stock tires, and is in 5th. That being said, the most I'd want to stay at is about 55 speedo, which is about 67-68 actual with the 37's. It takes way too much throttle to maintain speed above that....welcome to a 12 valve.

 

If you post your question in another thread i'll answer it in more detail.

 

Have you checked your gov. pressure?? also you can check your 3-4 shift pressure. even though it doesn't engage if you have pressure there then it means its shifting your problem is else where. check that you have power to the solinod.