Was pulling the RV over the past weekend, a 27 foot TT, about 7500lbs. Going thru Tennessee, North of Johnson City on Rte. 91 heading to Cherokee National Forest. No signage to warn you of anything, and I found myself on a steep as hell upward grade, very winding road, could only do maybe 15 to 20 MPH. Very narrow single lane road, no shoulders, no pull-offs, nuthin but road. I had no choice but keep going. By the time I reached the top, my Isspro had pegged on 280 degrees!

I mean there was nothing I could do, couldn't back up, couldn't pull over, couldn't just stop in the middle of the road and block the road for 30 minutes at a time........

Anyway, my thought is to have all the fluid flushed completely out with new installed at my dealer, and hope for the best. Any other ideas?

 

The ATF+4 is a synthetic fluid so it can handle the higher heat longer than conventional oils, but it's a good idea to go ahead and have the system flushed.

MikeyB

 

You could get a deeper pan for your tranny to hold more fluid, just a thought.

 

A question for you? Where is your isspro temperature sensor mounted in relation to the tranny fluid temp you saw on that trip. Just curious because I have the same guage and pull the same trailer weight and never went over 195 even in stop and go San Francisco traffic on the last trip we did. Did you have the tranny in tow/haul mode or the gear selector in drive? Man that is hot so soon as you can replace that fluid.

 

A complete fluid change is in order. ASAP. At that temp you get about 2000 miles out of your oil. I will look for the chart and post as soon as I find.
tom


According to this image I have exagerated the situation a little. Sorry, but you need new oil soon non the less
tom

 

I bought the return line from Massdiesel. So I was seeing the real thing coming out of the trans. I was in normal mode and the selector in drive. I've tried the tow mode and I really don't see the need for it. I was going so slow, the trans stayed in low most of the time. Occasionally it would shift into second, but as soon as I had to back off around a sharp turn, it was back into first. It was a matter of a bad condition that I couldn't get out of. I'm gonna make an appt. with my dealer ASAP, the truck has set since getting home. They want $200 for the flush, sounds high, but I guess it's the cost of fluid. ANd I want the dealer to do it for warranty purposes.

 

If you're reading the fluid temp in the hot line right out of the converter, it can be 30*F or more than the temp in the pan and overall tranny. It's only at that high temp for a brief time before it gets to the cooler. If your transmission temp light didn't light up on the dash, your PCM didn't see 260*F out of the converter. One or the other may not be totally accurate. I like to put the transmission temp sensor in the pan for the reason that's where the overall temp of the transmission is, that's where damage will occur from high temps with clutches and valve body, and the brief spike in temp between the converter and cooler isn't as harmful to the fluid as long term pan temps that high. But that's just my opinion. Like reading the temp of your torch flame at the tip instead of out there where the work is being done.

 

If no one were behind you, you could have put it in 4 low, and held it in 1st/2nd with the motor up around 2k to keep the fan blowing good. That helps my truck a LOT when im in the field going slow pulling a goosneck/wagon up/down hills.

Eric

 

A lot of the problem is these stupid torque converters dodge puts in there. They're way too loose, and slip like crap under conditions like what you describe. Where you were was perfect to overheat the transmission-too slow to lock the converter and get rid of the slip. I've had two 04.5 autos, a 2500 and a dually, and I'd have liked to have an aftermarket converter in both. This is why all aftermarket converters for these trucks are tighter than stock.

 

I was pulling my Rockcrawler . about 7,000 pounds trailer and rig plus camping equipment. I was in drive, tow/haul mode. I was climbing the hill up to Shaver Lake, CA. Looked at the tranny temp gauge and it was about 250-260 and it up shifted funny. I pulled it into 2nd gear and the temp started coming right now. I went back down there three weeks later and as soon as I hit the bottom of the hill I put it into 2nd gear and the temp never went over 180.

 

I don't think the $200 fee for the flush is too bad. I had an auto on my previous truck and when I had it done with standard fluid it was about $140. Granted the synthetic is expensive but you get what you pay for.

Additionally, the $200 is cheaper than a new tranny if they stick you with the bill.

 

Put it in 4 low on dry pavement? And with a switchy, winding road? Wouldn't that put the whole drivetrain into a major bind? That doesn't sound right to me. Am I wrong?

 

It wont matter as long as you arent turning to tight, but you are right. Wouldnt want to turn to hard with it.

Eric

 

Put a mystery switch in it-would have locked up in second and kept those tranny temps in check!!