I'm putting this out there in hopes that some of you that are pretty hot on Automatic transmissions can help me decide if I have a problem and am about to cook my tranny.
I have a 1998 4x4 Durango with a 5.2L and 4 speed Automatic. It came from the factory with the "heavy duty service group" and the "trailer tow group". I have owned this truck since it was new and it was mainly a daily driver and hauled a 2,500 lb boat on the weekends. When I first got it, I installed a K&N air filter and wanted to put in a shift kit to insure a long life for the tranny. Couldn't find one like the old style, you know, new plate, take out a check ball, replace a spring. It seems you just put in a chip. I installed a stage one RV chip. It firmed up the shifts and gave it a quicker throttle response. It is now just our tow vehicle and sits unless needed. I recently bought a travel trailer and am setting it up to tow for family campouts. The truck is rated to tow 5,600 lbs [that's off the sticker on the truck] The trailer is 4,600 lbs. My concern is the tranny overheating. I dropped the pan and changed the filter and refilled with the 3 to 4 qts of oil at 50,000 and 100,000 miles. When I did this the dealer said I have one of two trannys. One uses a metal filter, the other a plastic one. I believe I have the metal one and I wrote "44RE" in my notes. After reading many stories about cooking the trannies while towing, I installed a tranny temp gauge in the line from the pump to the cooler in the radiator. It then flows through an aux tranny cooler in front of the radiator,this is also factory. Recently at 112,000 miles I removed the line from the tranny to the cooler and pumped out 13 qts of oil as I added it to the pan. Now I have changed ALL the oil. When I was doing this, I got no flow out of the cooler in park. I know the tranny is suppose to pump something like ten times the oil in neutral so I put it in neutral. Oil came out and and everything was great so I completed the oil change. My concern comes from driving 30 minutes on the highway, I have a tranny temp of 110. When I come to a stop, I put in neutral so I get max flow through the cooler and temp jumps to about 160. Should I assume I'm still getting sufficient flow in drive going down the road? The last piece to the puzzle is when it is parked for lets say three weeks and not ran, you start is up, put it in gear and it acts like the torque converter needs to fill up first before it will move. If I put it in neutral for about ten seconds, it will take right off if then put in drive. One guy I talked to said something about a check valve not seating and that if I didn't want to fix it, just make sure I put it in neutral for a bit after an extended period of time to fill the converter and I'll be fine.
I think that about covers it. Sorry to be so long winded but I wanted to get all the info needed in here. From where I live, I needed to pull 4,000 ft in elevation before we get to where were going and I want to make sure we don't cook it on the first trip.

 

the trans does NOT pump fluid when the transmission is in park, so you should not have been getting flow, that is normal, as for the letting it fill up, i agree with what you were told, the check valve isnt seating and is letting the fluid drain out of the system so just make sure to let it refill before driving it, or change the check valve

 

Should I assume I'm getting enough flow going down the road? and that when I stopped and put it in neutral and the temp climbed way up, this is just a normal increase because of the added flow in neutral?

 

Oh yea, one other question, does anyone know at what temp you start doing damage to the tranny? or that you get into the viscosity and thermal breakdown? From what I have read, it follows the engine temp pretty close. 210, 220 is OK, but getting up there. 250, 260 not good. Does anyone really have any kind of a spec?

 

master tech will have all the specs on that, just give him some time to chime in for you, but chances are that as long as the truck is shifting fine while you are driving that the fluid flow is up to spec

 

210 would be the magic button for me. Put a 180 thermastat in there and that will hep keep it down.


ATF+4 is better at handling heat with better viscosity improver's.

 

i think hes talking about trans temp, not sure if there is a t-stat in that line

 

He is talking about the transmission temp. The fluid goes through the radiator to pre-warm the oil and also cools it when hot. The radiator is a 2 piece. There is a couple of rails in it that acts as a cooler/warmer. Then if the truck is equiped with a HD tow package this section is a littler bigger in those radiators. In these Tow package install trucks W/HD cooling package it also includes a small transmission cooler located between the radiator and the condenser to aid in cooling for towing. On the other side when it is cold outside it also helps to heat the oil.

If you are running a 195 T-stat it warms the trany oil to 195 F. To help in aiding the cooling especially for towing you drop in a 180 F T-stat and that itself will drop the trans temperature as well.

I would place a Hi-Flow 180 T-stat in that thing besides it will help keeping your heads from cracking between the intake and exhaust valves as the heads don't like the heat from the 195F T-stat. The heater isn't as worm but the truck will have a lil more power and better burn.

 

ahhh ok that makes sense now thanks for clearing that up

 

Sounds like wise advice, thank you. So am I getting an accurate read of tranny temp putting the sending unit in the line from the pump to the cooler in the radiator? I have read many opinions on this and used the logic that the highest temp I will monitor will be between the pump and the cooler. Not the line from the cooler, mounted in the pan or mounted in some test port.