Towing and transmission pros

[12V Ford]

Also, almost all (if not all) of the heavy duty eatons have oil coolers on them. I can tell you that it is probably necessary for hauling heavy, expecially when your grossing 110K going over Wolf Creek. The transmission was an 18sp and it didn't get into the too hot range, but the motor and rear end did.

 

[Kirwin]

Nv 5600

The NV 5600 is the most heavy duty manual tramsmission that Dodge has ever used. I have had my transmission temperature gage installed for about 2 years now and this is what I see. Truck empty at 70 MPH, 90 degree day the transmission will run about 190 F. Truck towing (24,000 lbs GCW) 65-70 MPH 90 degree day, The transmission will be about 220-225 F. Climbing a hill in 6th towing I've see it up over 245 F. Shift to 5th pulling the hill at 2400 RPM, which is about 58 MPH, and temperature will drop do to the 1 to 1 straight through power transfer. I'm not sure what "too hot" is for a manual transmission. I rarely see differential temperatures above 200 F though. Ken Irwin

 

[Kirwin]

Too hot for a manual transmission?

Also, almost all (if not all) of the heavy duty eatons have oil coolers on them. I can tell you that it is probably necessary for hauling heavy, expecially when your grossing 110K going over Wolf Creek. The transmission was an 18sp and it didn't get into the too hot range, but the motor and rear end did.

How hot is too hot for a manual transmission?



BJMarshall I am tending to agree with you. The NV 5600 is an extremely stout transmission when properly set up and used within its design parameters.



There have been a few NV 5600 failures documented on the TDR. If you weed out those that are Hot Shot hauling, and those that sled pull or tow trailers with more weight than the GCWR on the trailer alone, there are very few failures. These are light duty trucks that were not designed to handle that kind of "use". Sure you can overload it some of the time and it will not break; but do it every day and someting will show up as the weak link. One bad shift and the instantaneous torque that is absorbed by the drive line behind a CTD with >600 lb-ft on the input shaft will break alot of things. Just MHO Ken Irwin

 

[CumminsPower98]

My NV5600 conversion is still running fine. I have put 290k miles on it and 265k of those were Transporting RVs. I was loaded about 43% of those miles from about 15k-22k GCW. I just quit the OTR thing last month so now it's back to a daily driver. I have been running Amsoil MTF 5w30 and draining at 100k intervals.

Anyone know anything about NTN-BOWER brand bearings? I replaced my D80 carrier bearings at 358k on account of a no preload from the factory and 21k miles later while switching to a lighter lube I found the right side bearing had failed badly. The reason I say this is maybe the rebuilds are getting cheap bearings. I agree the 4500 really isn't made to run that hard all the time so it probably has nothing to do with the quality of the bearings.

 

[JRS]

If you put in cooler/pump setup use AN fittings and braided hose like they do in race cars.