Wiped Out: NV4500 Input Shafts

[LarryB]

FWIW

My trans temp and diff temp can run up to about 220f when pulling hard in the hills. Cool down to about 160 on the flats. It usually takes up to an 1/2 hour for the temps to come up from cold and stabilize when on the flats. Both running LE. I was surprised to see them this warm and almost always the same (diff/trans). When I flip the gauge switch back and forth the needle seldom moves.

 

[Ross]

transmission fluid

My NV4500 pukes fluid in the summer 105 F+ when loaded heavy and running hard. This is common for me and a lot of the guys I haul with. The fluid boils and pukes out the vent. The underside of the truck is pretty grimey because of this. All I do is make sure that there is plenty of high quality, clean fluid inside. I don't run a trans temp, so I don't know just how hot it's getting, but it must be pretty high.



So far, 105,000 miles on the transmission. I've just recently developed a harmonic vibration from the transmission in 5th gear between 58 and 62 mph. At the same speed in 4th, no vibration. Also, no vibration when coasting in neutral in the same speed range.

 

[Fast 1]

Larrys right about the temps. It takes at least 1/2 an hour for trans temps to change. If you shift to fourth when pulling the temps will drop to 180 or 190. Then if you shift back to fifth, they will return to 220.



Lack of oil was the problem. Where did the oil go? Either it leaked out the front or back seals or vented out the top.



The oil had to go somewhere for the transmission to get low.

My guess is it vented a couple too many times and become low.



CUMMINS TORQUE + . 76 RATIO CHANGE + 4 QUARTS = HOT TEMPS



CUMMINS TORQUE + 1 TO 1 RATIO + 4 QUARTS = NORMAL TEMPs



We need to apply less torque or keep it in 1 to 1 ratio (fourth gear) or add more lube capacity if you want lower transmission temps, so they don't vent. I think most of you will turn the torque down , right.

They don't vent at a normal temp, they vent when thier hot or overfilled alot!!



Normal life and operating temps for manuals from anyone would be good to add to this post.



Fast Coolers

Verlyn Fast

 

[Turbo Thom]

Joe:

You may have seen one of the trannys I shipped back to Charlie. The input did not have any spurs on the edges of the gear. That was at 196,000. I am at 229,000 now and am on the third transmission from Charlie. He has been great on replacing them , but the install is getting is me down. Last time I was stranded in the middle of nowhere Lousiana on I 20. I will say this, his fifth gear fix is right on. I have had no trouble at all with it. Just the other parts. When I change fluid in the transmission I will be going back to Amsoil. I DO NOT care for the syn-torq.



Do I hear WAR?



. . Preston. .

 

[Sled Puller]

Here we go.......

The transmissions had the required amount of factory lubricant.



The engines DID have horsepower modifications.



They were both Hot Shotters, so they are assumed to be maxed out on weight, or over.

Dodge cannot void your warranty for the coolers or another lubricant unless it is proved to cause the failure.



Do we all agree that our drivetrains are bare minimum for the STOCK Cummins engine? (no brainer there)



So with a modified engine, we are stressing the components beyond what Dodge intended. 50 or 100 hp over stock is easy, cool horsepower, can be had with a stock exhaust and makes an INCREDIBLE improvement in towing. Hills that were 4th gear, are now 5th over, easy. Trouble is, that poor little 5 speed only has 4 quarts of fluid, and it does not matter that the engine can pull that hill, the 5 gear is straining-and making heat.

Some drivers can FEEL when they should gear down--tons of power or not, know what I mean?



Don is right, I would be foolish to tell you Amsoil could have stopped the above shafts from failure.

Amsoil looks better on paper, and could withstand intense heat longer, but we don't know how much better or longer.

The Redline MT-90 looks very good too, but I have not tried it.



What we do know, is the Factory lube was put in this transmission to take care of a stock truck, get Dodge out of warranty with an accepted amount of failures, and hope they trade or buy a new trans after warranty is over.

I believe the Factory lube HAS taken care of the majority of the transmissions out there.

I also believe a lot of guys are reaching the factory lubes limits.



What we deal with on this site, is the few thousand that take their trucks to the extreme.



On other threads, guys seem to be concerned with their lubes being exactly what the factory calls for. But our trucks are no where near what they were from the factory.



How many times do you fix the 5th nut to factory specs before you get the fully splined mainshaft?



I installed a Genos trans filter, and a Mag-Hytec cover when I got my truck, my first BOMBs. I could care less about warranty, as I intended to keep the truck for a long while past warranty. I also bought the best lubricants I could find. These preventitive maintenance items were MY warranty to myself.



If you haul max loads, and have BOMBed the engine, and love blowing past those Cornbinders on the hills, you are killing your 5 gear lube.

If you don't trade every 2 years, you should at least put a set of Fast Coolers on the side, (BTW, I do NOT sell Fast Coolers!) and change your fluid often. I suggest once a year or 30,000 to 40,000 miles.

I prefer another lubricant and an HD input shaft, but to each his own. (Coolers are coming soon, Genos filter will be off. )



Keep in mind your owners manual was designed for the average majority, not Crazy Bombers!





If you plan on keeping your truck a long time, haul heavy loads,with a BOMBed engine, and think the factory "lifetime" fill of 4 qts is plenty, please post your transmission pictures in the future on this thread!J

Just my thoughts, observations from what I have seen the last couple years on this site.



Gene

 

[NVR FNSH]

Re: Here we go.......

Originally posted by MGM



Do we all agree that our drivetrains are bare minimum for the STOCK Cummins engine? (no brainer there)

Gene

How many miles on the SynTorq?



So, does the above statement mean that you believe our trucks are barely adequate to haul/tow the amount listed on GVWR/GCWR? I'm talking about frames, brakes, axles etc - NOT engines



Brian

 

[Sled Puller]

No, I meant the clutch, transmission, transfer case, differentials are the bare minimums for the torque the Cummins produces at stock levels.

Meaning I would not want any lesser components in there.



Just gaining a little hp puts the tq levels beyond the stock clutch and 5 speed input shaft ratings.



Gene

 

[C Schomer]

My towing temps are average - 160 if I'm poking along, up to 235 highway. I've noticed speed does WAY more than load for raising temps - trans and diff. I'm thinking... hotshotter/speed/melted headgear - makes sense to me! When I first saw the fast coolers I wondered why they stopped with short thick fins instead of more thin fins and longer! I think the basic idea is good but there's room for improvement on the design. Radial fins, like on an air cooled cylinder should be better. Make it look like a Porsche cylinder! I'd like to see before and after temps. Craig

 

[NVR FNSH]

Gene,

I knew what you were referring to, I just had to make a little jab where I could get one in. If people agree with you that DC used components that are already maxed out in those areas what makes you/them believe that other components have so much margin in them as to allow grossly 'over rated' towing? Increase the hp/tq OR weight loading and the stress on all those components goes up.



Seriously, how many miles on the SynTorq when the trannies failed?



Brian

 

[Don M]

I dont agree with DC that the trans oil is a lifetime fill. Too much contamination can occur just with weather changes over a lifetime(condensation)

Changing the stuff sooner is the best way to go.

Heat concerns were one of the problems the engineers had to deal with when they put the NV4500 together. The Syn-Torq was developed to deal with the heat.



Testing by Joe Donnelly showed that no oil ran cooler on the dyno than the Syn-Torq. This kinda backs up the claim from NVG about heat control with Syn-Torq.

Believe me, if another oil will work better than the Syn-Torq I would try it.





My own testing will at least give me some answers.

Hammer or MGM, you guys bring the oil and I will test it on the dyno for you to see. You can have a peek at the leaks too.

I already have some old Syn-Torq in my trans we can use for the heads up. You bring the Asmoil. I will pay for the dyno time.



We all know heat is from friction. If the super dooper Amsoil is cooler running I will eat crow here on the TDR.



Don~

 

[Sled Puller]

Ahhh, I see how you want it!



I guess you could say we are not concerned with safety here. Sad but that is the truth.

Now that I have a clutch to handle the power, an input shaft to handle the clutch getting the power to it, what fails next?



At the pulling track, U-joints and transfer cases. ( And 3rd gear, plus the transmission case cracked, but the HD input shaft held!)



Towing a trailer, probably your stopping ability, or you steering ability.

Even if you are loaded legal, a 400 hp Cummins will overpower everything behind it up a mountain, or a long grade with a headwind.



The mileage?

Why, it is a LIFETIME lube, the mileage is moot! It just happened to reach the end of that transmiision's life!



Seriously, I don't know, I can find out though. Surely a Hot Shotter would change it once in a while???

 

[Sled Puller]

Don,

I could care less about a dyno run. I know what I have seen.



I know that Enterprise transmissions stay in the field, not swapping in and out all the time.



I will post the first input shaft wiped out with Amsoil in the gear case, I promise.



You may not want to hold your breath, though!

 

[Fast 1]

If you check out Standard Transmissions web site you will notice the transmission that is behind the most HP / torque is the NV 4500, it's their # 1 hottest selling transmissions. Hot tranmissions and selling transmissions in the same line. Kinda funny? My banker never thought it was funny evertime I had to replacing one!



Fast Coolers

Verlyn Fast

 

[NVR FNSH]

MGM,

What kind of loads were these hotshots towing/registered for? I'm guessing they were registered for ~35k - 40k GCWR and near that number a large part of the time.



I'm willing to bet that the turned up engine combined with the heavy weight (grossly exceeded mfg ratings?) are the root causes of the failures - basically, the trans (gears/bearings/capacity/shaft dia/etc) is not designed for those kinds of loads. I highly doubt that increasing the fluid capacity and using a 'better' fluid would have prevented the failures. Those upgrades might have marginally increased the time to failure but if you're exceeding the design limits of the components those upgrades are only a band-aid.



Anybody got a connection at New Venture that can tell us what the max rating is for the 4500 & 5600?



Brian

 

[Don M]

Brian,



Check this page here from New Venture



http://www.newventuregear.com/transmissions.html



Also try and contact Kenneth Koliba from NVG. He can help you with lubricating issues. He can help explain how the mineral based stuff was dying in the transmissions in early developement stages and running super high temps. The main concern is temp and the dyno runs show the Syn-Torq to be the lowest temp oil so far. With others heating up very fast. Even other synthetics.





the 4500 looks to be about maxed out at 21,000lbs gross and 460 ft lbs of torque.



the 5600 is higher at 26,000lbs and 550 ft lbs of torque.



Don~

 

[NVR FNSH]

Thanks for the info Don.



Funny how those max ratings for the trans are only marginally higher than the GCWR for our trucks... ...



Brian

 

[Fast 1]

New Venture gear has told me that they have tested these trannys up to 250 to 300 degress, and when inspected they do not show any damage. I forgot to ask how long they tested at those temps. Anyone know how long?



I would rather see one tested for 30,000-100,000 miles at 200 to 250 degree temps. with no damage. I'm sure it would look just like the this imput shaft.



The NV 4500 is tough and can probably handle about anything except to much heat. Which is caused by the lack of lube or the wrong lube, or the lubes condition.



If they can't handle the torque the shaft would have been snapped and not smoked.



It can handle the torque just not all the heat that torque makes.



Cummins makes torque!!!!!!!!!! Torque makes heat!!!!!!!!!!!!!

 

[NVR FNSH]

Verlyn - you're ignoring the thermal mass of the gear itself. It's a big *** heat sink. Bigger gear teeth - ie bigger guts - would handle higher loads/temps better. The shaft itself may be able to handle more torque than the stock engine puts out but what about the gear teeth? Hopped up engine + heavy loads = more heat AND more stress > FAILURE. Which came first? The chicken or the egg... If the pressure between the gear teeth is too high it doesn't matter what lube is in the trans - the lube will fail resulting in the failure of the gear. The pressure between the gear teeth is highly dependent on the engine torque AND load you're trying move. Increase gear tooth size > reduce the pressure.



Verlyn - I agree with you that more capacity and cooler temps is a good thing. I just don't think that additional fluid (syntorq, amsoil whatever you choose) and your coolers will make a transmission survive in a job it is not designed for.



What other applications are the NV4500 & NV5600 used in? I highly doubt that NVG &/or DC designed these trans for duty cycle of a hot shot.



Brian

 

[Sled Puller]

Brian,

That makes sense, but everytime you run close to gear failure, but not quite, your lube takes the abuse along with the gear.



If you look at it that way, a better lube and 2 more qts could make a difference.



Gene

 

[NVR FNSH]

Originally posted by NVR FNSH

Verlyn - I agree with you that more capacity and cooler temps is a good thing. I just don't think that additional fluid (syntorq, amsoil whatever you choose) and your coolers will make a transmission survive in a job it is not designed for.



What other applications are the NV4500 & NV5600 used in? I highly doubt that NVG &/or DC designed these trans for duty cycle of a hot shot.



Brian

Gene,

I agree with you (I can't believe I just said that ) IF you are not exceeding the limits of the trans. Not sure what the limit of the trans really is - but those 3 exceeded it.



As I said earlier, I'm guessing that the hot shots were waaayyy over 26k GCW.....



I'd still like to know the particular info about those trucks/trans and see some data for manual trans temps.



I wonder what the R&P looks like on those trucks.....



Brian