Transmission Failure while towing NV5600

[jelag]

OK here goes... ... . 04 3500 dually pulling a trailer that is 15-20K lbs most of time... . truck now has 216K miles and has never gone through a full tank of fuel with out a load.....



On the way back from Missoula MT yesterday..... 70 mph on the interstate... . heard a bad pounding sound from under the truck..... and had to limp into a small town off the interstate..... 2-3 miles or so... .



Called the shop and had another truck come with a flat deck trailer to haul the truck home on... . and a local logger on the way to Spokane hauled my trailer back for us..... Gave him a 100 buck tip for the trouble.....



Pulled the transmission this morning..... Pile of metal in the bottom of the case... Closest exhange unit is in Boise and is $2800. 00



No clue on the cause..... we've changed the tranmission fluid our self every 50K or so... and did it about 3 or 4 weeks ago... . We've always used and approved fluid... .



The stage 1 clutch we installed at 100K miles looks almost new... but we're changing the release bearing and pilot bearing to be on the safe side...

 

[NIsaacs]

Kinda sounds like you got some good service out of the transmission, considering what you use it for. However it sure would be nice to know just exzactly what failed. Maybe I am old and resist change, but with the light weight oil they are using in the trannys now days (I feel for fuel savings) i think the trannys will suffer. I would like to use 15-40 engine oil in my six spd, but i am afraid to, so i am still using the mopar stuff





"NICK"

 

[Gary - K7GLD]

Do you often tow those loads in overdrive?

 

[R C Cola]

transmission woes !

From what I read on these threads 200k is pretty good. At 434k I am on my 4th transmission. I was planning on moving up to a six speed for a beefier unit until I read on here of the guys having trouble like yours. Even though I work my truck 60 percent of the time, I am not happy with early death. I will be wanting to know more about the beefier Allisons or mid-size truck trannies.

Best of luck w/your rebuilld.

Let us know how it turns out. R C

 

[Schlickenmeyer]

Do you often tow those loads in overdrive?

Eh? How's that again? It's a manual...

 

[NIsaacs]

Eh? How's that again? It's a manual...

Manual transmissions have overdrive, as in 6th gear. Usually the failure of standard trannys.





"NICK"

 

[jelag]

YES, use 6th all the time to tow those loads... .



In WA, OR, CA the limit is 55 with the trailer... .



In AZ, UT, MT, ID the limits 65 - 75 with a trailer... and we go that speed in those states.



We never get to the limit in BC or AB Canada, the roads are too bad...



RC - I waiting on the 4500 and 5500... . going to move up to that truck based on how they build it... . We have an F550 and it has the ZF and at 350K miles its on its second transmission as well... .



Jim

 

[Gary - K7GLD]

Manual transmissions have overdrive, as in 6th gear. Usually the failure of standard trannys.





"NICK"

YUP - seems like most NV-5600 failures are related to towing heavy for extended periods/miles while in OD - low RPM - especially common at speeds lower than 60 mph really hammer 6th gear due to the jackhammer-like firing impulses of the Cummins at low RPM. The gears and bearings simply can't cope with what is the equivalent to "lugging" in an engine.



When we moved here to eastern Oregon, the frequent mountain grades, combined with narrow curvy roads, prevented me from using OD as I often did on the longer but straighter Sierra grades in California.



The "fix" in our case, was to move up to 285 TOYO M55 tires - the larger size gave a small OD even in direct, and allows comfortable engine RPM at road speeds in the 45-65 MPH range. That also allows lower EGT, and places far less stress upon the OD gearset/bearings in the transmission.



At least, that's my theory... :-laf

 

[MMeier]

YUP - seems like most NV-5600 failures are related to towing heavy for extended periods/miles while in OD - low RPM - especially common at speeds lower than 60 mph really hammer 6th gear due to the jackhammer-like firing impulses of the Cummins at low RPM. The gears and bearings simply can't cope with what is the equivalent to "lugging" in an engine.



When we moved here to eastern Oregon, the frequent mountain grades, combined with narrow curvy roads, prevented me from using OD as I often did on the longer but straighter Sierra grades in California.



The "fix" in our case, was to move up to 285 TOYO M55 tires - the larger size gave a small OD even in direct, and allows comfortable engine RPM at road speeds in the 45-65 MPH range. That also allows lower EGT, and places far less stress upon the OD gearset/bearings in the transmission.



At least, that's my theory... :-laf

70-80 MPH is not lugging along... 2100-2400 RPM'S, jelag, sounds like the same way mine let go at 128k. Currently having the original redone so i have a spare on hand in case (when) I need it. sounds like you are using 6 states, correct?

 

[NIsaacs]

I count seven states all mountain states, too! With the heavy duty use of jelag's trucks, the E-brake use probably helps some in the demise of the trannys, however since they seem to be on the road steady, the miles before failure is still good. I would think that since they are being used for profit (not for recreation) that time is money. Therefore, overdrive use would be mandatory, direct is too slow, especially in the 550 Ford. It is probably running 4. 88-5. 13 rear axle gears.





"NICK"

 

[jelag]

Nick



MMeyer is talking about six states dist... a company who has 25 or 30 stores in the Pacific Northwest... . Yes the transmission will come from them... . I sell to PTO - Sales, about 10 of their stores... . they have this transmission and the price was better... . and they are a customer... . but we need to truck and six states had the transmisson in Boise and it's coming over on a stock transfer... no frieght... to get the transmission from my customer would take 3 or 4 days and another 200 bucks or so... . so we got it locally.....



About 1/2 of our miles are at 55 or below... I'm about ready to go overseas to put together a deal with a new vendor... . he's also hooking me up with a wheel vendor... I'm going to get 19. 5" wheels for all my stuff... and switch to them... .



Jim

 

[NVR FNSH]

jelag,

What's the GCVWR of your truck and what's been done to the engine?



Sounds like it might be time to step up to a medium duty RATED truck - ie FL 60/70/80 - as opposed to hopping up a light duty truck (note I said truck - I know the engine is rated for the work load).



Brian

 

[NIsaacs]

Nick



MMeyer is talking about six states dist...



Jim

"Oh"





"NICK"

 

[jelag]

I think this answers the questions posed above... .



Truck is stock except for exhaust brake, air bags, air horn, bed liner, etc... . we don't do any changes to the engines because we have several trucks and several drivers... I've been afraid to modify the engines and have engine troubles, or add to the strain on the transmission or rear end... . Don't care to have holes in pistons... etc...



Actually we're at 32,000 - 33,000 most of the time... . I'm now in the process of buying a straight truck rated 52,000 - 58,000 lbs... with a 26 or 28 ft bed... .



I would have bought another F550 had the first one tuned out fine..... The current one that I have has had 3 sets of injectors, 2 transmissions, and one engine... . terrible costs... the dodge's have been costing me about 35 cents on the dollar compaired to the F550... . to keep running.....



Hope this helps...



Jim