G56 Update

[photowrite]

Yeah, I paid for the extended warranty. I'm keeping ATF+4 until the warranty expires. Even though my conscience says it's not designed to lubricate a manual. But I always thought ATF generally was able to withstand the high temps of an automatic. But could be wrong.

mfurrh, That is a welcome post to all the doom & gloom about towing with a g56. Do you tow in 6th gear up hill when the engine allows? Or do you always downshift to 5th even when the engine can pull in 6th?

Agreed. I have a strong suspicion that my G56 will easily take me past 100k, which will be several years, and I'll very much enjoy the drive and choosing my own gears all that way.

Maybe/probably the dual-mass flywheel will die early, around 100k, the one in my '96 Ford did, but replacing the clutch and flywheel were all that was needed. The aluminum-cased ZF-S5 transmission filled with Red Line MTL for close to two decades just kept on working, including more heavy pulling in 5th/overdrive than I care to admit

Of course, I'll have to wait and see, my 2500 is 6 months young and has few miles on it. With the 3.42:1 gears I’ll have little need to pull grades in 6th if I don’t want to, direct should work fantastically (was too low in the ’96 with 4.10:1).

James

 

[NIsaacs]

ATF was used as factory fill in some manuals in the 60s. If you think about it, the same amount of HP and Torque goes through an auto as goes through manual. It is also used as differential lube in many front wheel drive cars, manual or automatic. I am not saying the ATF is the best, but it is capable. It also has a 194 VI (viscosity Index) which means the viscosity is somewhat stable as the temperature rises.

On the surface this seems to make sense, however the power levels of the Cummins is the issue. The power, travels straight through an auto but on a manual transmission you are talking power transmitted through the counter shaft. This requires 3 shafts, 4 gears, 5 bearings and the case, all receiving huge amounts of torque, except 5th (direct). For years medium duty trucks used direct drive trannys and big trucks used twin counter shaft's to harness the power. The little 4spd that were used back in the day, lasted, because they were direct drive in high gear, the gear you spend the most time in. If the 6 spd manuals were direct in 6th, they would last forever, almost:-laf Give me a direct drive 6spd and 3.00 rear axle gears

The reason transfer cases rarely fail with ATF is because in 2 high they are straight through also.

Nick

 

[Bob V]

My G56 went 120,000 miles with the ATF in it. There are a lot of others that have done longer also. The Pennzoil sycromesh that is used in the NV5600 has a viscosity of 8.7cSt at 100c. ATF+4 has a viscosity of 7.5 cSt at 100c. pretty close to the same, and people get decent life out of those also. I am not saying there is not better fluid out there fir the g56, its just that the factory fill is not as bad as some think. A vast majority of Ram G56s have ATF in them, they are not failing any faster than any other manual trans.

 

[RVTRKN]

There is some truth to that, but it is not what the manufacture recommends, and the viscosity is a lot higher. cSt @ 100ºC

17.5

 

[Bob V]

I was comparing the Pennzoil scyncromesh to ATF+4. I was just comparing oil that is used in the 5600 to the ATF in the G56.

 

[photowrite]

My G56 went 120,000 miles with the ATF in it. There are a lot of others that have done longer also. The Pennzoil sycromesh that is used in the NV5600 has a viscosity of 8.7cSt at 100c. ATF+4 has a viscosity of 7.5 cSt at 100c. pretty close to the same, and people get decent life out of those also. I am not saying there is not better fluid out there fir the g56, its just that the factory fill is not as bad as some think. A vast majority of Ram G56s have ATF in them, they are not failing any faster than any other manual trans.

Agreed.

Did your G56 last only 120k before a rebuild, or you sold it?

I'm okay with replacing the dual mass flywheel and/or clutch, but would like/hope to get more miles out of a manual trans.

 

[Bob V]

Traded it in, never had a problem with the trans, the clutch-yes.

 

[mfurrh55]

Mine has 141,000 on it and i went 124,000 before i changed from ATF to the mobil-delvac 50 wt., mine has never been rebuilt or had any problems, i could probably still be using the ATF too, Monte

 

[Regcabguy]

The ATF with the smf constituted cruel and unusual punishment. My trans sounded like it was going to implode. Shifted fine though and the fluid was always pink and magnet had a fine fuzz.

 

[RVTRKN]

Yup, sounds like there's marbles in mine, Im going to strait Mobil Delvac 50 wt., when I service my transfer case and install an oil temp sensor. Fuzz is always on my magnet too, but this time the oil is pulled through a filter, before the oil is pumped through a cooler in front of the radiator. So I wonder how much fuzz I'll see this time.

 

[Joseph Donnelly]

If I had a G56, I would review the recent TDR magazine article on lubes for it, and also consider Torco RTF which has worked great in my NV4500, NV5600, Borg Warner Super T10, and Jerico. One more nail in the coffin for the G56, pushing me to the Aisin, was that I did not want to use ATF but wanted the warranty on a trans which could have issues.

 

[RVTRKN]

I wished I had the luxury you had in your decision. In 07, little was known of the G56, and what was known was the AD version that is probably the better of the two. My choice would have been the Aisin, had I the same choice today. The $2000.00 option is cheaper than what I've had to spend to date on my G56.

 

[Joseph Donnelly]

I might have considered the G56 in 2013 if it had an iron case. I don't like the aftermarket clamshell stiffener because it will trap heat, is expensive, and may or may not really stiffen the trans enough and in the needed directions.

 

[RVTRKN]

You don't need the girdle if you keep the Aluminum cool, that's the secret to the G56. Also, if you run too thick of an oil, the heat retaining properties of the heavy oil, can cause it to run hot. Thats why I went through the expense and time researching the installation of my cooler system. I can control the temperature, even when temperatures are over 100* ambient. The only test that remains is towing my 5ver up grades when temps are over a 100*. The other plus to the cooling system is, its adaptable to the NV5600 when I convert mine to a NV5600.

 

[wiley75]

Wow, until reading this thread I didn't realize my G56 was such a "piece of crap". I actually enjoy my transmission. I like that I can leave it in a gear and really use the torque curve of the Cummins the way I want to. An automatic won't let that happen. Which is how they get away with the higher torque ratings. It is kinda smoke and mirrors though because you can't really pull the peak torque out of it before it downshifts. I dislike the G56's tall gearing in reverse though. Also my clutch is also starting to slip under full throttle acceleration when towing my 5th wheel. Kinda disappointing at only 54K miles, on a truck that is not abused and is bone stock. But I still like the G56. I don't for one second believe that the G56 is weak, needs a aftermarket cooler, needs a girdle, or anything else. I run the recommended ATF in it, synthetic. Just use it for what it is intended for and it'll last forever. Of note, we use ATF in marine transmissions where I work that have 1000HP or more running thru them. Do not fall for the myth that thinner oil does not lubricate as well.

 

[RVTRKN]

Your right about the torque, with the standard transmissions, and ATF. But unless you plan to maintain the OEM DMF by replacing it with the clutch, you will find a different transmission with the SMF. I defended the G56 until my clutch failed under Dodge's updated programing of my 6.7. Search my threads from 07 to 09 on the G56, you will find positive threads and posts on the G56. But my opinion has changed due to the installation of the SMF, the G56 does not hold up to the torque that the powerful CTD puts to the flywheel. The different oil is nessesary due to the unleashed torque that causes the G56 to chatter under the low RPM torque the CTD produces. ATF can not cushion the gears and bearings like a MTF/oil can. YES IT IS A POS, and I have the browned bearings to prove it, RUNNING under the GCVWR THAT Dodge says it's safe to pull with. I have had both, the G56 and the NV5600, and it's not even close to the stout NV5600 transmission.

 

[AH64ID]

RV, you probably chose the wrong clutch for your application... unless you have some very big mods missing from your signature. If the clutch is the main basis for your hatred, you should have changed clutches.. lots of people dislike their DD clutches in both NV5600's and G56's.

My dad's 06 G56 has the SBC OHD in it and aside from the pedal feel there isn't a noticeable difference between the DMF and his SMF with a warm transmission. On a cold transmission, for about 5-10 miles, there is minor gear rollover from 1000-1200 rpms.. sometimes, and it is MINOR enough most people wouldn't notice it and it was really only noticeable after UDC tuning removed the stock injector rattle as the rattle was louder.

You love to bash the G56 and praise the NV5600, but have you considered that the G56 has been in service longer and the lower hp/tq rating the G56 has had is the highest the NV5600 ever received. The highest G56 GCW is also higher than the highest NV5600 GCW.

The NV5600 peaked at 325/610, and only for about 1 year (MY 04.5-05, 05.5 brought the G56) and the highest GCWR was 23K.

The G56 peaked at 350/660, but started at 350/610, and GCWR is as high as 26K.

It's not a fair comparison thou, as the highest NV5600 GCWR was with 4.10's which aren't available in the pickup with a G56. 3.73 to 3.73 they are both 21K until the 2013's came out and the G56 jumped up to 26K in some applications, and 24K with 3.42's. The AD G56 did run a 23K GCW and when the AE G56 came out it dropped to 21K matching the NV5600 with 3.73's.

 

[RVTRKN]

Kind of deceptive on the rating of the NV5600 when comparing it, to then vrs now. Dodge didn't discontinue the NV5600 because it was incapable of handling the higher HP/TQ in the newer configurations, but because New Venture went BK, or reconstruction of the corporation. And Mercedes introduced the G56 to replace the NV5600, not because it was a heavier duty transmission that could handle the higher HP/TQ, but it was already available with other Mercedes vehicles.

As far as my clutch application goes, I know it is noisier than the other and have not confused the difference. The reason for the DD3250 is because of the surging during regeneration of the emissions that was updated in 09. If that was a screwup or whatever, it still exsists in my programming and that took out my clutch so that's why I chose the DD3250.

 

[photowrite]

Kind of deceptive on the rating of the NV5600 when comparing it, to then vrs now. Dodge didn't discontinue the NV5600 because it was incapable of handling the higher HP/TQ in the newer configurations, but because New Venture went BK, or reconstruction of the corporation. And Mercedes introduced the G56 to replace the NV5600, not because it was a heavier duty transmission that could handle the higher HP/TQ, but it was already available with other Mercedes vehicles.

I don't think that was his point, that the NV5600 was discontinued because of the ratings.

But like others haven noted, the G56 is not so horrible that it doesn't continue to work for many, and with increasing power and torque ratings as well as higher GVWR/GCWR.

 

[moparnut72]

From what I have read parts for the NV5600 are somewhat hard to find due to the short production run. They are supposed to be pretty pricey too. My 12V had the 4500, fabulous transmission. The truck had 240,000 miles with the original clutch and zero issues with the trans.

I wanted a manual with my new truck but after test driving the Aisin, no brainer. After 10,000 miles still very happy with it. Pulling the 5th wheel I no longer have to "drive" the truck ie: watching for hills, etc. I am more along for the ride. Love it.
kk