I just rebuilt my 46re to put in my 02 Durango 5.9 4x4. I'd rather bypass the radiator trans cooler and install an aftermarket cooler in front of the condenser, but I hear that may not be a good idea. I live in NW Ohio and it only gets below 0 degrees in very short stints occasionally during the wintertime, so I don't think it should cause a major problem. Not a large amount of stop and go traffic either.

Just want a second opinion, should I rig them up in series or should I give the trans its own cooling system? It may help to add I won't be doing alot of pulling with this.

 

Run it thru both. Radiator first, aux cooler second. If you are really concerned about cold temps, get a thermostatic bypass valve for the aux cooler. An external spin-on filter isn't a bad idea either.

Can I spend some more of your money?

Be sure to flush the lines/cooler REALLY well before running that new trans.

 

The radiator also serves as an ATF warmer to quickly bring the tranny to operating temp. I wouldn't eliminate it.

 

You can but I wouldn't. It adds a bit of volume and on a hot day, towing or not, both working together are just more efficient. Be sure to flush everything really good so junk from the old units doesn't ruin the new one.

 

What he said. Every time I bypassed the factory in radiator cooler with a standalone one I was replacing the trans very soon afterwards. Even when I went with a "way oversized" aux cooler. I always run the fluid thru both, aux first then in-radiator then back to trans. Looking at the side of the trans the front line feeds the cooler while the rear one is the return.
I also put in an in line filter somewhere along the return line. They make them that look like an oversized fuel inline fuel filter. Then change it again with the 1st (engine) oil change after the trans replacement, then with every pan drop fluid and filter service after that.
This filter is not meant to be a substitute for flushing the cooler upon installing the new trans

 

What do recommend flushing the cooler lines and cooler with?

Would reverse direction flushing be better?

I thought of hooking up a small electric fuel pump and running a solvent in reverse, the flushing the solvent out with ATF.

I also have the option of using up some left over dextron.

 

Some variety of solvent, even mineral spirits would work, flush both directions, with solvent, then both directs with clean ATF. The electric pump idea sounds like a plan.

 

I'd flush it both ways with a hose and some radiator flush. Might as well flush the whole cooling system while you're at it.

 

The radiator as a warmer is a good point.