68 RFE transmission went up to 220 degrees "locked" climbing the Donner pass at GCVWR.

[Bug Out]

Most of you know I've had a few CTD RAMS,1997 3500 5 spd, 2005 3500 dually 6spd, 2012 max tow-(68RFE), 2013 2500(68RFE) and now a 2013 Mega dually(68-RFE) CTD. The max tow would flirt or go up to 200 degree's, and the 2013 2500(68RFE) would never get close to 200 degree's unless city driving , all towing the same 5th wheel.

Today, I'm pulling the same hill I pulled last summer with the 2500 and the transmission temp slowly continued to climb until it hit about 220 degree's. prior to this, the clutch fan would engage and cool the engine off quickly. Once the transmission hit 220, it up shifted and held the hill at 1700 RPM's and would not down shift...It was in cruise control. However, now the transmission temp began a gradual drop in temps until it got to 200 degree's.

Oddly enough, now the engine was staying at around 215-220 and the clutch fan just barely coming on...The only time the eng temps dropped was coasting down hill.???

I know 220 is not dangerous for engine or transmission, but none of the other CTD's with the 68 RFE did this. I thought all 2013 and up got 2 transmission coolers??

Is it possible the transmission is not locking completely? if so, is something the dealer can adjust or reflash ???

My understanding is the truck had some heating issues with the previous owner, but according to the selling dealer,( I called and inquired) it was repaired under warranty.

I have 60 more miles and I hit 36K.

HELP!! What if anything can I tell a dealer, Carson city Dodge ( I'm in Reno for a week) is wrong?

Thank in advance for your help.

Ed

 

[GCroyle]

Sorry, I think everyone knows I don't know doodley squat about AT's and their behavior. But were you towing, uphill and running cruise control?

 

[RVTRKN]

My Trans cooler for my g56 which cools it very well, but I noticed when climbing at 23K GCVW, the cooler picked up heat from the intercooler and I actually raised the temp and I had to shut it down. Now I'm sure it's the same with an auto Trans cooler, I was pegged at 30 PSI Boost.

 

[Bug Out]

GCroyle, yes cruise control, 58 mph in 5th gear. Nothing different then the other (2) 68 RFE's which never got this hot.

 

[RVTRKN]

As I noted though, your going to gain heat climbing when at high boost loaded. The trans cooler is behind the intercooler.

 

[jus2shy]

As I noted though, your going to gain heat climbing when at high boost loaded. The trans cooler is behind the intercooler.

On 2013+ trucks, intercooler is slung low in the bumper, trans coolers are behind the 1st radiator on the front (There are 2 radiators to the engine cooling circuit that run parallel). Granted, I don't tow at GCVWR, so I have no idea what to expect. However, if you're having temperature issues, you could have a fan-clutch type problem (going by what you're describing), or you could also have a thermostat issue with your transmission if it's not allowing full-flow to the cooling circuit for some reason. However, I don't know the full operating parameters of the engine and trans. If it didn't show the dummy gauges hitting any alarms or creeping close to them, I wouldn't be concerned honestly. Possibly transengineer could shed some light on this.

 

[Bug Out]

Thanks for the replys. I'm going to call Carson Dodge tomorrow.

 

[Newsa]

R VTRKN;2438076]My Trans cooler for my g56 which cools it very well, but I noticed when climbing at 23K GCVW, the cooler picked up heat from the intercooler and I actually raised the temp and I had to shut it down. Now I'm sure it's the same with an auto Trans cooler, I was pegged at 30 PSI Boost.[/QUOTE]

Speaking of G56. Had my first real challenge a few days ago backing this camper up a 12% incline into a camp site. Had to ride the clutch not to go to fast and had to Rev the engine a bit to keep it from dying. Got a bit of smoke from riding the clutch. But still have clutch plate remaining and didn't warp anything with the heat. The one time I wished I had an automatic . Lol

This was after an 8 hour day of driving with horrible construction and and Atlanta rush hour traffic. Exhaustion set in

 

[Newsa]

That day we passed a 4500 carrying 4 cars that was driving a little too fast and put his rig in the trees off an embankment

 

[transe]

Ed, what was the engine speed before the upshift (when you were running 220°)? Are you running any kind of scanner where you can monitor converter slip (engine speed minus turbine speed) and/or TCC state?

Sounds like you may have been running in 5th gear unlocked, and then shifted to 6th gear (locked). That would account for the difference in temps. But I'd think the shift and lockup schedules should be the same between your two 2013 trucks, so I'm not sure why the newer one would behave differently. Unless maybe for some reason you're having to run deeper into the throttle in the newer truck (which would delay the upshift point). Also, I'm not sure why it wouldn't have been running locked in 5th gear.

 

[Bug Out]

TransEngineer, I had it in cruise control, as I have in the past with the other 68RFE, and had the speed set between 55-59. I had the trans manually in 5th. it was max rpm's at about 2500. What would cause it not to lock up? On one occasion it did sound like it downshifted into 4th and did not lock.

 

[Bug Out]

Well, I talked tom "Tom" at Carson city Dodge, who spoke to "Don" who is a tech there. 220 is "acceptable" for towing max and 240 would be the panic point. The crappy thing is, I have 60 miles and its all my mess...$$$$

Off to Genos for another pan..... Maybe that will help.

 

[transe]

TransEngineer, I had it in cruise control, as I have in the past with the other 68RFE, and had the speed set between 55-59. I had the trans manually in 5th. it was max rpm's at about 2500. What would cause it not to lock up? On one occasion it did sound like it downshifted into 4th and did not lock.

Unfortunately, without actual data (showing the exact speeds and throttle opening) it's difficult to determine what the trans "should" have done. I would expect it to be locked up at highway speeds, but again without data it's hard to say conclusively whether it was operating to plan, or screwing up.

Ask your dealer to at least make a record of your complaint (at current mileage), such as a Repair Order that says, "Customer complained of trans running too hot (220°F sump temp), TCC not engaging while climbing Donner Pass with trailer. No DTCs, could not duplicate complaint." That way, if there is a record that this issue existed under warranty, it should still be covered for a repair (for this issue) at a later time.

Maybe they could set you up with a Wi-Tech data recorder to take along on your next trip, so you could record what it's doing. If so, you'd want to do a quick checkout run first, to make sure it's recording all the data (engine speed, turbine speed, output speed, current gear, target gear, TCC state, and throttle opening) correctly.

 

[Deleted member 995608]

Here ya go Newsa

 

[Hoefler]

When we traveled towards Yellowstone with the 08, we drove over the Big Horn at a snail's pace due to the road construction. Road speed kept the transmission in first gear most of the time and occasionally second, but no lockup. The temp on the transmission pegged my gauge at 285*. Had no place to pull over, had temp warning going off and engine fan roaring. With a trail of vehicles behind us, we could not see the end, and the escort truck nowhere in site. I stopped in the middle of the road, shifted to 4wd low, and continued. transmission shifted right on up into 5th gear and locked up, within a mile every thing was in the normal range. I drove in 4wd low over 7 miles pulling our fifth wheel. Was able to pull over after getting out of the construction zone, checked the fluids, trans looked good, no smell or discoloration. Called my dealer in Mo. and explained the ordeal, told me it sounds like I was not going fast enough to have the transmission lock up. I was told to monitor it and continue my trip. If I had any issues, to call him, and he would arrange for me to get into a local shop. I have never seen anything close to them temps since. When I returned home, I had the dealer check it over, said no damage or evidence of malfunction, and sounds like it dealt with the situation as designed. I drove that truck for an additional 85,000 miles and never had any issues with it.

 

[AH64ID]

TransEngineer, I had it in cruise control, as I have in the past with the other 68RFE, and had the speed set between 55-59. I had the trans manually in 5th. it was max rpm's at about 2500. What would cause it not to lock up? On one occasion it did sound like it downshifted into 4th and did not lock.

Just to clarify the 2500 would have been the 4th downshift right?

 

[Bug Out]

Hoefler, 285 degree's is definitly in the "fry the transmission" zone.. 220 is not danger high,(since the atf is synthetic) but none of the other 68 RFE's i had got close to that. My understanding is 2013 and up got the "dual transmission cooler", unlike 2012 only the max tow 3500's did. I'm hoping that back in Saltillo they didnt forget to put the second cooler on....:-laf

 

[Newsa]

Here ya go Newsa

Thanks J.

I don't get much phone service out here. Have to grab it in short spurts

 

[Tuesdak]

R VTRKN;2438076]My Trans cooler for my g56 which cools it very well, but I noticed when climbing at 23K GCVW, the cooler picked up heat from the intercooler and I actually raised the temp and I had to shut it down. Now I'm sure it's the same with an auto Trans cooler, I was pegged at 30 PSI Boost.

Speaking of G56. Had my first real challenge a few days ago backing this camper up a 12% incline into a camp site. Had to ride the clutch not to go to fast and had to Rev the engine a bit to keep it from dying. Got a bit of smoke from riding the clutch. But still have clutch plate remaining and didn't warp anything with the heat. The one time I wished I had an automatic . Lol

This was after an 8 hour day of driving with horrible construction and and Atlanta rush hour traffic. Exhaustion set in

By chance were you in 4x4 Low range doing this?

My 2WD doesn't have this option. But I use 4x4 on steep slopes in reverse even with automatics for safety. It is something else when you break the rear wheels loose in reverse with a trailer. It gets hairy going sideways quick if you loose rear traction without 4x4 locked in. I have lit up both rear wheels in reverse on dry pavement/concrete before I learned it's a bad idea.

 

[Hoefler]

My 08 had dual coolers, one on the engine with coolant going to it and the other was mounted in front of the radiator.