NV 5600 rattle and hot

[corprimo]

We're towing a 12,000 lb 5er out west with our '05 3500 with 69,000 miles on it. I have FastCoolers for extra capacity and am running Amsoil Manual Trans oil which meets Dodge specs. Yesterday, at the top of a long grade, my trans temp guage was at 250. I've seen 225 of late, but never 250. The rattling sound at start off that I've seen described as "normal" on here is now occurring when pulling hard in 5th and 6th gear - going up a grade. At least I think it's the same sound. Louder at higher RPM when I gear down, goes away if I let up on it. I've got 8 quarts of transmission oil in there, and just added two more quarts in hopes that will quiet and cool things down a bit. Any suggestions or warnings? I'm afraid if I bring it in to a dealer they will just say, "can't reproduce symptoms... "

 

[Gary - K7GLD]

The rattling sound at start off that I've seen described as "normal" on here is now occurring when pulling hard in 5th and 6th gear

"Pulling hard in 6th gear" up grades is a surefire recipe for NV5600 disaster! OD is not strong enough, or meant for heavy towing use in the grades - the engine might take it, but 6th gear most likely will not, for any extended period - the bearings just won't survive - extra lube or not...

 

[Grizzly]

I'm assuming you have the 3. 73 differential. Only suggestion I have is, when pulling heavy don't use 6th gear as often, especially going up hill even slightly. 6th gear is more of an overdrive and is not meant for pulling heavy uphill.

 

[GCroyle]

8 quarts + 2 quarts = 10 quarts?



Do you have 10 quarts in it?



TDR guru's, does that much oil create heat from all of the extra work being done to move all of that oil? Or is that an acceptable amount of oil considering the additional cooler volume?



Transmission noise can be created by a failing transmission, I think we can all agree on that. But a failing clutch disc torsion damper CAN allow the transmission to make noise because it is not effectively dampening or filtering out the noise from the engine pulses.



Good luck.

 

[jelag]

We have an 04 that we tow a 20K lb trailer... . and we had issues with 6th gear... if your on straight and level roads its fine but after the overhaul we decided to drop to 5 on any grades...

I agree with Gary... . it can be the clutch as well... but the rise in oil temperature would send me towards the transmission... .

One thought, we had another truck with a drip from the tail shaft... on inspection we found that the lube shop hadn't really been checking the transfer case and it was low on oil making some noise... we found a kit and pulled the transfer case off and kitted the transfer case and solved that issue...

We now do all service in house so that we know that it's been checked... .

Let us know what you find...

 

[corprimo]

Thanks for the comments. Yes, 10 quarts with the Fast Coolers. We're in Prescott Valley about to start making our way back to Portland OR where we're storing the rig now. With this '05 truck we've towed the 5er coast to coast, did a month long caravan into Mexico and been over the Alaska Highway 3 times, so I imagine the damage to the transmission is done. I'll gear down more and will post if the extra two quarts make a difference in the noise or temperature. Noise is worse at higher RPM's when gearing down, but if I keep my right foot light I should be able to reduce/eliminate it. At this point, the noise is not noticeable to the average person, so we'll see. By the way, Jim, the PacBrake is still working perfectly with close to 70,000 miles on it. With my '97 Auto, transmission was the weak link, so I bought the NV 6 speed thinking it would be bullet proof. Weak link again...

 

[Gary - K7GLD]

'97 Auto, transmission was the weak link, so I bought the NV 6 speed thinking it would be bullet proof. Weak link again...

Not really an accurate or fair analysis - too many owners fail to understand the application and operation of overdrive gearing, especially as provided in the NV-5600 - it's designed primarily as a fuel saver in more level and relatively lightly loaded travel conditions - and was never intended for steady, extended use under heavy loads and steep grades.



The problem is, the excellent torque of the Cummins fools folks into thinking all is well, as they obliviously chug along up those grades with apparent ease - and because the ENGINE seems happy, they assume all the rest of the drivetrain is fine as well.



In your case, the OD gear/bearings possibly were the first to go - but U-joints and differential probably aren't all that far behind. After all, exactly how close ARE you to the manufacturer's specified GCVR with your fully loaded setup?

 

[kscheffler]

With 10 quarts do you know what level this results in the transmission? Do you have the fast coolers with the plexiglass cover so you can see the oil level. I am just trying to determine what level your oil is in the transmission with 10 quarts? It must be above the fill hole for the fast coolers?

 

[amsoilman]

We're towing a 12,000 lb 5er out west with our '05 3500 with 69,000 miles on it. I have FastCoolers for extra capacity and am running Amsoil Manual Trans oil which meets Dodge specs. Yesterday, at the top of a long grade, my trans temp guage was at 250. I've seen 225 of late, but never 250. The rattling sound at start off that I've seen described as "normal" on here is now occurring when pulling hard in 5th and 6th gear - going up a grade. At least I think it's the same sound. Louder at higher RPM when I gear down, goes away if I let up on it. I've got 8 quarts of transmission oil in there, and just added two more quarts in hopes that will quiet and cool things down a bit. Any suggestions or warnings? I'm afraid if I bring it in to a dealer they will just say, "can't reproduce symptoms... "

First off, normal fill capacity fior the NV-5600 is only 5 QUARTS. if you have a fast cooler, I would not think it should take more the 2 QUARTS extra, for a total of 7 QUARTS. Too much oil can do some real damages to your transmission!

I have the same setup, but without the fast coolers, and I pull a 12,000 pound toy hauler, but I never pull a steep grade in overdrive. (6th gear)

The only time I get any rattleing is when I take off in second gear, instead of 1st.



Wayne

amsoilman

 

[corprimo]

We put on 207 miles this afternoon, kept speed down and geared down on hills trying to keep EGT to no more than 1000. No noticeable noise unless I push harder than that. Max temp was a hair over 225, usually between 200 and 225 with outside air between 70 and 90.



Questions: what should transmission temp be when towing?



What are the symptoms that transmission is about to fail?



7. 5 quarts brings level to fill hole with Fast Coolers. Fill hole is on top of fast cooler. With all the extra horizontal area I'm guessing 10 quarts is about the same as an extra quart without the coolers.



I'm wondering if this would be covered on drivetrain warranty. Owners manual says nothing about 6 th gear being overdrive or babying it.



If I had wanted a light duty truck I would have gotten a Toyota. I wanted a HD puller, bought the 1 ton, amsoiled everything, monitor and maintain it well and now I'm hearing that "Ram Tough" dies not apply to gear 6 in the NV 5600. Go up a hill, gear down. Headwind, gear down. He'll, next thing I'll hear is if U eat too much for dinner I'd better gear down. If the engine and everything else holds up to towing and the transmission doesn't, I still think the transmission is the weak link. Oh, we have never exceeded weight ratings on this truck.



Thanks for all input!



I may stop in at The dealer in Carson City and chat with them.

 

[NIsaacs]

I would stop somewhere and have the oil changed and check for any metal or contamination.



I see in your sig. that the engine is stock? You should not be able to damage the transmission unless you were deliberate about it. That transmission started with the HO and is twice the size of the Getrag 360. I have 330,000 miles on mine, still original with engine mods. I have 170,000 on the 01 with mods and still original. With only 70,000 miles on yours, if it is bad you bought it that way.



Keep in mind, towing, the transmission will at least run the same temp as the engine (heat sink).



I have always said, the new trucks with water weight, fuel saving oil is not in the best interest of manual transmissions. I run 15/40 engine oil in all mine and change every 36,000 to 50,000 depending what I have been doing with them.



One of the hardest things that can happen to a manual transmission is a bad pilot bearing. Too much clearance on the input shaft tip can cause the input drive gear to miss-mesh with it's counter part on the counter shaft and cause failure. It might have been damaged even at the factory.



As far as your rear axle goes, if you change and use good oil (85/140) you will also not hurt it any. They are tough. Mine are original.



Keep us posted.



Nick

 

[blacksheepdiesel]

There are three keys to longevity for the NV5600.

The first is overfilling the transmission by dumping 6 qts of the correct fluid into the shifter hole for a stock transmission with no coolers. I have used both the Mopar and Royal Purple SynchroMesh, preferring the latter by far. The rear main bearing does not get much oil splashed on it so overfilling helps get more oil to keep the bearing cool and lubricated.

Over filling does not create more heat in the transmission and thus expedite the demise of the transmission. The fluid in this transmission is very thin and it takes almost no effort for the gears to sling it around. Overfilling the oil in an engine or automatic is death. For the NV5600 overfilling is vital.

The second key is downshifting before 6th gear is grunting. In my '01 with 3. 55 gears that was about 60 mph when going up a lengthy or steep (or both) grade. On flat ground I drive at 55 mph pulling a camper and the transmission has suffered no ill effects whatsoever. As stated by others, the engine is so strong it makes the grade seem somewhat effortless, but the transmission left in 6th gear is getting the brunt of the forces and suffers for it.

The third key is to change the fluid at least by 100,000 miles, sooner if the shifting becomes difficult.

Currently have 300,000 miles (half or more are pulling miles) on a Blumenthal reman that is starting to make noise so it will get replaced. Without overfilling, downshifting and changing fluid it would not have made it this far.

Overfill, downshift and change the fluid, your NV5600 will love you for it!

Godspeed,
Trent

 

[GaryOwen]

I had over 500k miles on my NV5600 in my 03 and never had any problems with the transmission. About half of the time I was towing campers. I did overfill by a quart or two and used Amsoil. I rarely down shifted, but I had 4. 10 gears.

 

[Buffalo]

If you get a chance, read the article by Dr. Joe Donnelly about the re-build of his NV-5600 on page 76 of Issue 67 (Feb. Mar. April 2010) by Standard Transmission & Gear.

This is a great article about the NV-5600 & how to make it bullet-proof. Dr. Joe gives a history of what he has used in his trans (dates & mileage) & has good pictures of what the gears look like. Standard Tansmission & Gear will install a "Power Lube Package" into the transmission,upon re-build, to enhance the lubrication in areas that weren't adequately lubed, in the stock form. They pay close attention to shimming of endplay of the main shaft & cluster shaft, which, they say is critical for longevety. Apparently, the manufacturer was not as concerned about this as is Standard Transmission & Gear.



BTW, I called ST&G & they recommended 8 quarts of Amsoil fluid with the use of coolers. I have a trans fluid filter on the right side of my trans & have a cooler which I am about to install on the left side. I have also over filled my trans on the last fill & will do so again.



I found this article very interesting & well worth the read.



Hope this helps.



Joe F.

 

[HBarlow]

I had a very satisfactory experience with the NV-5600 in my '01 Ram. My truck was always factory original except that Joe Donnelly installed a set of Bosch motorhome 275hp injectors when the truck was new. My truck had the 3. 54 gears and gauges. It also had a Jacobs e-brake installed by the dealer before I took delivery and I always downshifted and used the exhaust brake for deceleration. I tranported with that truck and pulled my own trailer many miles before I became a transporter. In short, I worked the truck pretty hard.

For the duration of the time I owned the truck I pulled every grade at full power, tach down to but never below 1600 rpm, and the pyro at 1300 to 1325* in sixth gear. I always let it pull, never downshifted unless the mighty Cummins couldn't hold 1600 rpm. I pulled every single grade out west under those conditions for 325,000 miles without engine damage.

The NV-5600 developed a noise and Standard Transmission in Fort Worth rebuilt it at 302,000 miles. The top cover had been off for a clutch replacement and leaked slightly. I lost a little fluid over time. I allowed the fluid level to get low and didn't follow the practice of overfilling the transmission. This caused lube starvation to the big bearing resulting in wear. If I had been more careful, provided better lubrication, I think the OEM NV-5600 would still be working today. In other words I believe my NV-5600 failed due to poor maintenance by me, not from pullling hard in sixth gear.

Yes, it is true that sixth gear is probably stressed fairly heavy by making it work like I did, making it pull grades under full torque and only 1600 rpm. When Standard disassembled the transmission sixth gear did show wear . . . but it was not the cause of the rebuild. The tranmission was not noisy except at low speeds in the lower gears.

 

[corprimo]

Up Date

We're now in Eugene Oregon, transmission is no worse than before, but I'm babying it. Truck now has 70k miles, and I've changed transmission oil at 9k, 30k and 60k - Amsoil Manual Transmission oil each time. Fast cooler has dipstick with magnet - hardly any residue on it when I checked it last week. No symptoms whatsoever when driving truck w/o the trailer. I'll check with some Portland dealers this week and see what they say. Maybe 225 degrees is normal when towing 12k pounds? But the rattling noise under heavy pull is not.



We've got several things to fix on the 5th wheel too - 60,000 miles on it with 5 trips over the AK highway, plus living in it while we built our house, has taken its toll...