G56 Torque rating

[Shadrach]

What I want to know is how much torque will a G56 take? Is the problem just the clutch or is it the trans as well? As you can see by my sig my clutch in not stock. While I am not racing, with the Smarty I could easily exceed the stock ratings. I am a conservative ( older ) driver but towing a TT up a mountain does require some torque. I would say my ratings is 365 HP and 675 TQ. While I don't see this as being a problem I am curious as to what a "safe" limit is ? - and don't say stock Shad

 

[HBarlow]

Manufacturer's torque rating on G-56 transmissions through MY '12 was 600 ft. lbs. The Ram website claims an increase to 675 for the '13 Ram.

Joe Donnelly wrote an excellent article published in TDR magazine a while back discussing the inherent weaknesses of the aluminum case G-56 as well as the DMF/clutch assembly. Joe recommended an external girdle or cradle to strengthen the case and a conversion to the conventional single mass flywheel and clutch for high torque heavy load applications. He also discussed service life expectancy and rebuild of the G-56. I read the article with interest but probably don't accurately remember the details as it didn't apply to me.

 

[NIsaacs]

I am not sure what the official torque rating is on the G56, however it is more than the Getrag 360 and the NV4500 and look at the power mods that they stand up to. I would use 5th as much as possible and bend the floor board with your right foot

Nick

 

[Shadrach]

I know my clutch will take what I give it and I can't afford the girdle. I don't anticipate any problems. Shad

 

[RVTRKN]

If you stay within Dodges ratings (GVWR,GCVWR) then the G56 should give you normal service life. Shadrach, I noticed your truck is an 03 MY how did it get a G56, and did it come with a NV5600?



If your going to tow with the G56 over Dodges GCVWR, then it should have a girdle installed, but normal use, per Dodge, you should be fine. The weak link is the DMF, which with your SBC clutch installed you should have gone to the solid flywheel. My 07 C&C now has the clutch slipping under load, but is due to Dodges updated program for my C&C that I had done in 09. It basically, during a regen, ups the HP and torque and took out my clutch when it surged towing 22K GCVW. I'll be installing the SBC Con OFE with the flywheel and hydraulics upgrade. If you are towing over the G56 ratings W/O a girdle, the gears will not align properly as the transmission case flexes.

 

[cerberusiam]

While I am not racing, with the Smarty I could easily exceed the stock ratings.

Yes you can and will exceed its ratings, especially if you remove the TQ management for better throttle response. Best guess is the G-56 is rated in the mid-500 pretty close to the NV5600.

However, the TQ rating system is not a simple linear equation. It is an attempt to come up with a TQ number the trans will function with over a set period of time without failure. Does not mean if it is rated at 550 it will break at 600 TQ, or, even 700 multiple times.

High TQ has a babit of flexing the case and spreading the main and countershaft out of alignment causing massive damage, that is what the girdle attempts to address. The harmonics when the DMF is removed also raise havoc with the inuput bearings. A fluid damper helps a lot to cut out vibes.

For the most part with a mid-level Smarty tune and rational driving, no mashing the throttle uder load and low rpms or lifting hard at high rpms, you should be fine for xxxx units of use. The xxxx is influenced by load and driving habits so you can influence it.

 

[LNaugle]

We built an 6. 7L truck that made 685 hp to the rear wheels and it flexed the case so bad that it broke 4th gear which if i remeber right is part of the mainshaft, and broke sixth in half leaving the blocker ring holding it together... not sure what the torque was as Industrials dyno dint have a way to measure it at that time. I would deffinetly recommend the outer girdle made by lanzar smith (?) if your are turnin the power up or swap out for a built nv5600, which can be expensive but so is rebuilding the g56 properly and still wont hold the power like an nv5600.

 

[cerberusiam]

We built an 6. 7L truck that made 685 hp to the rear wheels and it flexed the case so bad that it broke 4th gear.

About 1400 ft\lbs depending your fueling map and how hard it was loaded to start the run. :-laf G56 no likey those numbers.

 

[Shadrach]

First a little history for those who don't know. I bought the truck with a blown engine. It had about 356k kms ( about 221k miles ) on it then and I already had obtained the G56 and SBC clutch for a different project. The 03s clutch was almost worn out and the NV5600 turned out to have some issues so because I had the G56 and it was too expensive to use as a coffee table ornament I installed it in my 03. Since the G56 is used in the same body style in later years it wasn't a big deal. All I had to do was use the correct mount, stick and trans adapter and change driveshaft lengths. I had the NV5600 fixed and it is now in a 96 3500 replacing the NV4500. He loves it.

I have only set the Smarty to # 3 ( 60HP with timing - which I believe would also add about 120 lbs of torque ) That would give me 365 HP and about 675 TQ. I did this for pulling the TT thru the Rockies this summer. My total weight was about 8400 kgs ( about 18,5 lbs ) Without the Smarty the truck dynoed at 278 RWHP. That's 91%. Pretty good for a stock ( other than cam) engine. The Smarty is currently set at stock. I do have a 6. 7 damper to install but haven't had time. My new turbo ( Garrett powermax ) will arrive next week. There probably won't be any other power mods - no seriously folks. I don't drive the truck much during the winter and in the summer it is used for hauling things and the TT of course. I live 5 km ( about 3 miles ) from work so it seldom goes there. In the 2 years I have had it on the road I have barely put 20k kms ( about 12k miles ) on it.

Now you know the story and you got a lesson in metric as well Shad

 

[AH64ID]

You should be just fine at those numbers. The Smarty claims are rwhp gains, not crankshaft so I bet your closer to 375/700 at the crank. RWHP should be around 320/600, give or take.

That's not a huge load for the G56, but I would run a better fluid than ATF. I would look at either Amsoil MTF or Royal Purple Syncromax.

Manufacturer's torque rating on G-56 transmissions through MY '12 was 600 ft. lbs. The Ram website claims an increase to 675 for the '13 Ram.

Correct numbers are 610 ft/lbs 05. 5-12, and 660 ft/lbs for 13. Thou at this time it is unknown if there are any hardware changes for the '13+ G56's.

 

[Shadrach]

... I would run a better fluid than ATF. I would look at either Amsoil MTF or Royal Purple Syncromax.

I have thought about whether or not to change the fluid to something else, but haven't yet. I have read lots on here about it. One of my biggest concerns is the climate I live in. As I said I don't use it much in the winter. By "winter" I mean Dec-Feb when it does get cold, between -18 & -35 C ( 0 to -30 *F ) . I had the truck out yesterday, but it was only -3* C ( about 27* F ) so it's not cold yet My first truck had a NP435 with the bull low 1st gear. When I parked it at home I backed in and in the morning the reverse light would stay on for a few minutes until the gear oil became fluid again. Synthetics weren't big back then.

BTW How would you flush out all the old ATF so as not to contaminate the new stuff, whatever it may be? Shad

 

[AH64ID]

If you get it nice and warm and let it drain for a while it should shed enough of the ATF to not cause contamination issues.

I drove dad's G56 in mid 20°F weather last week with Royal Purple syncromax and it shifted better than my NV5600 with Amsoil MTF.

One way I warm the trans up in winter, really cold 0°F and below, is to put the xcase in N and put the trans in gear. I don't run the truck for long, 3-5 minutes, but that's enough that the trans really works better.

 

[NIsaacs]

About 1400 ft\lbs depending your fueling map and how hard it was loaded to start the run. :-laf G56 no likey those numbers.

I went to the local Dyno Days Saturday and the shop just finished an install of a twin turbo crate engine, CR5. 9 into an '03 Ford 550 with an auto. It put down 701hp/1234 tq. It was a nice clean install, however I noticed the fan was completely inside the fan shroud, it might run hot next summer.



Nick

 

[CKelley1]

you must have added the g56, the 03 came with a nv5600. we tow extremely heavy with g56's. get some trans-cools from genosgarage.com and mix one gallon synthetic syncromesh sae50 transmission fluid with one gallon 5w-40 synthetic syncromesh transmission fluid. most of our trucks are set at 430hp and 900 ftlbs torque, the one in my sig is set at 450hp and 970 ftlbs torque, we run the same conofe sb clutch.