NV 4500 Slags on Continental Divide

[Matt42]

I'm not sure that this is the right category, as the NV 4500 transmission that packed it in was on a '98 Chevy K20 6. 5 turbodiesel. But here goes anyway.



On Wednesday, 9/26 we were southbound climbing Lost Trail Pass in Montana, with a fully loaded truck and 3 ton equipment trailer. There, the last of the Syntorq oil in the Chevy's NV 4500 leaked past the defective seal into the transfer case. The transmission then did what you would expect with a GCVW of 14K on a 7% upgrade. The resulting noise was very much like exhaust on a 350 V8 at full throttle. The brake fluid in the clutch line boiled, and the clutch faded. We discovered the faded clutch while trying to shift into 4th at the summit. At that point, the transmission jumped gear and killed the engine.



(I need to mention that our Tempe, AZ based satellite phone service provider had *allegedly* damaged our Iridium phone, so we were SOL for getting help, as the phone was in the phone hospital. )



Once the clutch cooled, and the engine electronics rebooted, we determined that we could still move, but with considerable noise. Salmon, ID, was 45 miles of downhill and flat, so we limped in. Quality Motors in Salmon was able to get right on it. Disassembly revealed a damaged input shaft and countershaft, with most gear teeth chipped. The input shaft and bearing had overheated, melting the plastic bearing roller sleeves. They had a new transmission overnighted in by Friday morning. Bob and Jeff at Quality Motors are super people!!



That's twice for this truck, both on various parts of US 93. The first was a parting of the engine oil cooler line, which resulted in a complete disabling. Chevy drivers: Any clues as to what goes out next? It has 24,000 miles on it. My boss is now VERY upset for going low bid and not getting the Dodge.



Matt in AZ

 

[Champane Flight]

Heavy

I would tell your boss if he was planning to haul loads over the rockies with the 14k on a regular basis,to go with something a little heavier. Like a Freightliner with 8. 3 Cummins and a 10sp Fuller.

 

[Matt42]

Slagged 4500

The 14K weight includes trailer and truck. I would hope even a Chebby would be equal to a 6,000 pound trailer.

 

[Power Wagon]

That's a heck of a hill...

That's a heck of a hill. I pulled it from the Montana side once and the Idaho side once this summer on vacation. We drove from Missoula to Salmon and then from Salmon to the top and then over to Wisdom, Montana.



I don't know what your turbo engine would do... but my 65 Crew Cab Power Wagon and 27 foot travel trailer powered by a stock 318 2bbl lugged clear down to about 27-30 or so in 3rd in both directions. It got the downpipes from the exhaust manifolds so hot they turned blue.



I am very very surprised you were able to get down the hill into Salmon without something locking up big time.

 

[Power Wagon]

Originally posted by Matt Shumaker

I'm not sure that this is the right category, as the NV 4500 transmission that packed it in was on a '98 Chevy K20 6. 5 turbodiesel. But here goes anyway.





That's twice for this truck, both on various parts of US 93. The first was a parting of the engine oil cooler line, which resulted in a complete disabling. Chevy drivers: Any clues as to what goes out next? It has 24,000 miles on it. My boss is now VERY upset for going low bid and not getting the Dodge.



Matt in AZ

Here's a few tips:



Remove the plastic cover over the engine. That reduces heat around the injection pump.



Put in the best thermostat you can, and try to run it a few degrees cooler. It'll have more power, too.



Familiarize yourself with the location of the switch for the fuel supply pump on the back of the engine. It fails too often, and in some instances it quits. it can be bypassed with a jumper wire in an emergency.



Run the best oil you can. The turbo's oil supply route is convoluted and results in overheated oil reaching it. It's best if you can get the retro kit, if it is not so equipped (from the dealer) which will run cooler oil into the turbo. It changes the outlet location for the oil supply.



Open up the exhaust. More air is good.



Try to find someone who knows how to time it, and have them time it slightly advanced. This is a very tricky thing to do. It requires a scan tool and thorough understanding of the procedure. Seems to run better that way.



Good luck on the rest