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

[Newsa]

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.

I tried it first in 2WD (reverse). But lost traction despite the extra weight of the trailer tongue (weight distributing hitch is taking some of that off of the rear wheels) and despite the limited slip differential. The wifey was screaming at me to put it in 4x4. And since I was smelling burned clutch, I decided to give it a 20 mins to cool down and then used 4x4 low. I don't think 4x4 low is hurt any if you are losing rear wheel traction.
I wish reverse was geared lower than 1st on the g56. But they are the same.

 

[AH64ID]

I wish reverse was geared lower than 1st on the g56. But they are the same.

They where only the same on the early AD G56. On your G56 reverse is a little taller than 1st. 5.42 vs 5.94.

 

[RVTRKN]

I wish reverse was geared lower than 1st on the g56. But they are the same.

That and a cast Iron Case. :-laf:-laf:-laf:-laf:-laf:-laf

 

[Newsa]

That and a cast Iron Case. :-laf:-laf:-laf:-laf:-laf:-laf

You might be confusing the NV 5600 with the G56 AD? AH64ID. Thanks for the info. Didn't realize the difference

 

[AH64ID]

You might be confusing the NV 500 with the G56 AD? AH64ID. Thanks for the info. Didn't realize the difference

He wishes it had a cast iron case too.

 

[Newsa]

He wishes it had a cast iron case too.

I always considered Cast Iron to be superior to Aluminum. But the G56 has a higher input torque rating than the NV5600 did.

Only have 15,000 miles on the truck. Love the G56, although I would make design improvement suggestions if they asked.

 

[RVTRKN]

Actually the NV5600 is often used by hotshot hauling, using more power and GCW than designed for and is a sought after truck if you can find them low with low milage. If you take care of your G56 it will treat you well, but when the DMF fails, and it will, it will turn into a whole different transmission.

 

[Newsa]

Actually the NV5600 is often used by hotshot hauling, using more power and GCW than designed for and is a sought after truck if you can find them low with low milage. If you take care of your G56 it will treat you well, but when the DMF fails, and it will, it will turn into a whole different transmission.

What are the symptoms of the DMF failing? Is it caused by warping from heat? Or is it related to damping springs ?
No problems so far with the DMF.

 

[Bug Out]

I think I was able to duplicate what happened when the transmission temp went to 220+. I was coming up the Hoover Dam hill going south on 93 when the truck, in cruise control at 60 downshifted into 4th and DID NOT lock up. Once I realized it, I turned off cruise and backed off the throttle until it locked.transmission Temp never went over 205. 5 miles later, it again was in cruise, almost identical hill, downshift and locked right away. Ghost transmission.... Hytec pan going on anyway. The odd thing is this transmission and engine run much warmer then my other 2013. This RAM runs when towing between 210-220 degrees and transmission around 200. The other RAM would cool itself off to 200 engine and never went above 185-190 on trans fluid.The previous RAM trans fluid would cool down once the transmission locked. This unit, barely get below 200 transmission temp and stay right there..Kinda odd how 2 trucks same year, drive train run so different. I wonder how much weight a mega cab and s/box dually weight over a s/box 2500?

 

[RustyJC]

Those temps do sound strange. Towing our 19K GVWR 5th wheel on the flat and level Interstate at 65 MPH in 6th, I see transmission temperatures on the EVIC of ~170 degF and engine coolant temperatures of 203 degF, even on 90 degF days and above.

On a recent trip to the Davis Mountains in West Texas, the 35 mile stretch from Balmorhea to Fort Davis climbs from about 2500 ft elevation to 6000 ft. My transmission temperatures never exceeded 180 degF. We had 2 couples traveling with us towing slightly lighter 5th wheels (a 36' Mobile Suites and a 36' Heartland Big Country) with a 2012 Ford F-450 and a 2010 Chevy Duramax/Allison respectively. In their case, they both reported transmission temperatures of 205 to 210 degF during the climb.

Towing on the back roads of the Appalachians, I've seen transmission temperatures climb to perhaps 195 degF. One tow in the Ozarks involved about 1.5 - 2 miles of switchback roads up the side of a mountain that required long pulls in 1st and 2nd gears. I saw transmission temperatures of up to 223 degF at the end of that climb, but the torque converter never locked and speeds were so low that ram air through the cooling pack was minimal - it was about 95 degF outside.

On a long climb, I will see engine coolant temperatures rise to 219 - 221 degF at which time the cooling fan kicks in and pulls the temperatures back down to 210 degF or so before disengaging.

The highest transmission temperature I've ever seen was on a long, steep downgrade with a lot of curves that limited me to 30 MPH or so. I was using the exhaust brake and manually shifted down to 1st and 2nd gears where the torque converter never locked. When I looked down, the transmission temperature was 230 degF, but this was due to fluid shear in the torque converter and lack of ram air through the cooling pack - the engine coolant temperature never got high enough to engage the cooling fan.

Rusty

 

[Bug Out]

I know the temps are whacked..The original owner (still under 36k warranty) took it in for heating issues. the dealer allegedly fixed the issue.....Not if you ask me. Engine temps towing are a steady 210-220, fan kicks on but not like my other 2013 where engine temps would zip back to 200. transmission temps as I said above are in the area of 190+ to 200, steady. Even when locked it does not cool anything like my other 2013. the other would cool back to 180-185-transmission....not this thing.

gonna put a mag-pan on and hope it pulls some heat and contact the selling dealer who "fixed" the heating issue and get more details. If no luck, re-contact the original r/o and see what the deal was. Ed

 

[Bug Out]

AH64ID, sorry I did not answer your above post. The post went sideways...Yes, I was in 5th gear as I do all thru California as they have the 55mph limit on tow vehicles.. So it downshifted into 4th gear, but I did not hear it drop into lock...shortly afterwards, 220 was on the evic.

 

[RVTRKN]

What are the symptoms of the DMF failing? Is it caused by warping from heat? Or is it related to damping springs ?
No problems so far with the DMF.

My DMF didn't fail, the defected regen update back in 09 causes surging during regen and took out my stock clutch during a surge pulling 23K up a grade. This was at 35K miles, and I converted to the SBC SMF and DD3250 kit. For actual symptoms PM CKelley1 he has had several failures in his fleet of G56's.

 

[Bug Out]

I believe I'm getting a better picture of how/why this truck is running hot. I have been studying when the clutch fan comes on, stays on compared to my previous (2) RAMs, 2012 3500 and 2500 2013.

The previous two trucks, towing the exact same trailer, the fan would kick on around 210-215 and stay on until the motor cooled to about 200. The transmission never got over 200 on the last two RAMS. However, this truck, the fan kicks on at 215-217+ and stays on until it cools to 210ish, then disengages a bit. The transmission temp hovers around 200 on average etc. Only once and a while will the fan kick on like the previous 2 RAMS and sound like a Jet engine and the motor cools to 200 or so...

The selling dealer( I found the previous owner and selling dealer info the truck) had told me the truck was in for a warranty repair early on for "over heating" issues. They did not elaborate on the issues but said it was fixed.

My question is : If the previous owner tells me the over heating issue was the same, will it be covered under warranty?(I'm at 37K now)

2nd question: Can the clutch be tweaked via the ecm when to come on/off etc?

3rd question: If the dealer balks at looking at it etc, how do I find out who the warranty rep for the area is? I discovered the issues before 36K. But you know how the dealer etc are.$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$...

I priced the clutch fan on line and prices are from 300-500$

Thanks for your help/input in advance.

 

[Newsa]

I could be wrong. But as long as the truck is running, they don't have to do warrantee repairs. That's why I extended my warranty to 70,000 miles

 

[Bug Out]

NEWSA, hope your wrong.. But, your probably right. I'll find out in the next week.

 

[transe]

Bug Out, don't waste any money replacing your fan clutch. Sounds like the fan clutch works fine - what's different (apparently) is the fan CONTROL (done by the PCM). I suspect the dealer will tell you it's "working as designed."

The fan control is not simply "on" or "off". There is a target fan speed that varies based on a number of factors (such as engine coolant temp and trans sump temp, but also several others). Yes, it should be possible to reprogram the fan control logic (to kick the fan on at lower temps); you'd have to contact some of the aftermarket "tuners" and see if they can do that for you.

 

[AH64ID]

Bug Out, don't waste any money replacing your fan clutch. Sounds like the fan clutch works fine - what's different (apparently) is the fan CONTROL (done by the PCM). I suspect the dealer will tell you it's "working as designed."

The fan control is not simply "on" or "off". There is a target fan speed that varies based on a number of factors (such as engine coolant temp and trans sump temp, but also several others). Yes, it should be possible to reprogram the fan control logic (to kick the fan on at lower temps); you'd have to contact some of the aftermarket "tuners" and see if they can do that for you.

Exactly, unless there is a code the fan is working as the PCM is controlling it and replacing the clutch will yield the same results.

FWIW the fan on my 05 is nearly silent and I can watch the clutch PWM and fan rpm on my touch and know it is working.

 

[Bug Out]

I spoke to the original owner yesterday who told me he was having the same problem with the clutch fan not coming on, or fully as is normal around 210 etc. took to dealer at 10K etc and said some temp sender, gizmo thing was changed and it worked fine after.

Anyone have a idea what type of sender temp unit etc this might be? He said several of his friends who own the same type RAMS had the same issue. Wonder if a recall was in effect or?