Engine/Transmission (1998.5 - 2002) NV4500 questiion/s

[gtwitch]

Yesterday I was towing back from the mountains with my 99 CTD 4wd 2500 as I have for the last 10 or so years and towing a 5 snow machine enclosed trailer at about 8500# when the transmission NV4500 got very hot and would not shift at a crossroad. Got out and looked under truck and transmission was probably 200F (very hot to the touch and very strong smell of 90 w oil. I serviced the trans at 110K, 9 years ago with Amzoil heavy duty gear oil and installed a Fast-Cool on the PTO port and filled to about 1.5 pints overfull by filling thru the top to the fill port , putting that plug in and then filling the additional oil thru the top. I check the oil in all the boxes twice a year and I checked this level by loosening the fill plug until it just comes out and if oil comes out at all I call this good.
At the time that the truck was not drivable yesterday, I pulled to the side of the road, called my sons wife and had her bring their Chevy 2500 8.1/Allison to pull the trailer home and while waiting an hour or so and letting things cool down the truck would go into and pull in all 5 gears +Reverse, so upon hooking the trailer to their truck, I drove the truck home 50 miles and checked the trans oil this morning and it is still over full some? and then drained from the Fast-Cool drain plug on the side of the transmission about a pint of oil for a sample. (Transmission is still slightly above full at this point) The sample is very black with some very small magnetic particles in this sample pint of oil. I have never had any indication of any problems to this point at now 201k miles.
Does this sound like I need to find a trans or rebuild or purchase a rebuilt???

Any comments!!

gtwitch in wyoming

 

[SAndreasen]

Contrary to popular belief these transmissions are not lube for life assembly's I would never ever go more than a year on oil . I change mine annually I also run the Pto filter kit and that helps the oil stay fairly clean the filter adds a little capacity as well . You can try flushing the transmission I use diesel dump it through the top let it sit overnight drain it and keep doing it till its clean . After 9 years and you have never changed it and no magnet on the inside bottom of trans case ? there could be some metal particles in the oil . Could also be a clutch release problem ? I would definitely change transmission oil install a magnet and see if it does it again . Quad 4x4 has the filter kits www.quad4x4.com there site kinda sucks to find anything on but they do have them .

 

[gtwitch]

SAndeasen, Thanks for the input, I did see the filter kit after I had put the Fast Cool extrusion on the PTO years ago and did not feel like draining and installing it. Bad on me!! and also I am at fault for assuming the "lube for life" attitude in this scenareo! I guess I will try the diesel dump a couple of go a rounds. Would you put a quart of some kind of oil in with the diesel and just run it briefly to turn all the gears and bearings and let set overnight and drain or just diesel, set, and drain??? and do this a couple or three times till clear???? I have already had the clutch release problem and a new NAPA china chincy clutch kit which I wish I had gone Southbend route!

Thanks again.

anyone else comment??

gtwitch in wyoming

 

[tripl-e]

A failing ball or roller bearing would explain both the overheat and excess ferrus material in the drain oil. Likely a countershaft bearing. Towing a load on the highway would just exacerbate the situation (5th speed drives through the countershaft). The Cummins makes so much noise you probably can't hear the bearing failure starting. Drain it completely and strain the drain oil through some filter paper or a stack of rags. There shouldn't be anything coarser than dust. The evidence there will likely convince you to rebuild it (or replace it with a 5600!).
Good Luck!

 

[gtwitch]

Thanks again, I will put the drain oil thru my standard Coffee Filter trick and look! I will keep this post going as I go on and maybe some photos if I can figure that out.

gtwitch in wyoming

 

[SAndreasen]

Have you had a chance to figure anything out?

 

[gtwitch]

Update to my NV4500 high temp issue. Found time and the weather cooperated and I drained and put the oil thru a paint strainer and there was very little residue and very little of it was magnetic!!! Next Question?? Is there a magnet somewhere in the trans?? Maybe attached to the inside of the PTO cover or something? As there is no drain plug and you drain it using the PTO cover I was just wondering? I will do a diesel flush after lunch and filter that also thru a paint filter and look at that residue. I will keep this thread going.

gtwitch in wyoming

 

[CM_Guest]

I'll put my money on a leaking rear seal in the transmission. That it wouldn't shift then but does now is a dead giveaway. Why? It's a hydraulic clutch. I had pretty much the exact same situation with my '97 Chevy 2500 with an NV4500. A hot transmission = hot clutch fluid = no shifting. The trans got hot because it was low on oil. It was low on oil because it was leaking it, and not on the ground where it's obvious. The trans output seal was leaking trans oil into the transfer case, the trans oil level got low and it got hot enough to apparently boil the fluid in the clutch slave cylinder. So the clutch wasn't disengaging when I pushed down the pedal.

I played truck driver and shifted it without the clutch long enough to get to a gas station to check things out and when I popped the cap on the master cylinder it was full of fluid. After sitting for 15 or 20 minutes it was back to "normal" so I knew it had to be a heat-related problem and the fluid must have boiled. Which meant the trans was way hot and had to be either low on oil or shelling out. It sounded and drove fine so I suspected low oil and with no oil on the ground it had to be going to the transfer case. I drove it another 60 or 70 miles home at lower speed. I checked the TC oil and it was WAY overfull and the trans was way low.

That happened with the truck alone driving down the highway 65-70 mph or so on a cool fall night. Obviously towing is going to make a big difference and yours got hot enough to do the same even being only a "little" low on trans oil. I'll bet if you drain your transfer case you're going to find it way overfull.

As far as running Amsoil gear oil in the trans, New Venture has always recommended Castrol Syntorq or its OEM equivalent for NV4500s. I'm not a member of the "correct police" by any means but when a manufacturer recommends ONE lubricant there's usually a very good reason why. Usually having to do with its compatibility with specific materials used in transmission components. Like synchronizers, friction materials, seals, etc. I was going to put Brand X synthetic gear oil in my transmission when this happened to me too, but when I got to thinking about it it made a lot more sense to use EXACTLY what the manual said to use. For all I know, the WRONG oil might have contributed to my problem in the first place. Just something to think about when you're changing transmission oil during the seal replacement.

 

[gtwitch]

CJ, Thanks for the response! All food for thought, especially the Syntorq. The first thing that I checked next morning was the fluid level in Trans and transfer case and the Trans was still over full (not sure how much) as I had checked it in Oct before elk hunting as I always do (it was over full then) and I was sure that I would find it low when it was so hot, but not so and the transfer case was about 1/4" or a little more low and I had topped it off in Oct also. The clutch slave cylinder/Master Cyl thing may have been something that I did not consider and I don't remember if I tried to "trucker slip shift it" at that crossroad or not. After it cooled for about 15 min I could shift into all gears using the clutch and all felt normal so after my daughter in law arrived with their Chevy 8.1 and we put the trailer on that, I drove on 50 miles to town and of course no problem or heat. I am leaning towards thinking Amzoil just is not right or it just failed/gave up after 100k miles.

gtwitch in wyoming

 

[gtwitch]

A little more information, I just finished with 3 rounds of diesel (1 gal) and 1 qt of oil flush each time and the last flush I filled the trans from the top (shifter out) and ran about 3 to five miles each time and then drained and filtered the drain fluid thru a paint filter that goes in a funnel and examined the residue and there was very little ferrous material and some fiber/rubber gasket like material, but in my opinion, not anything to be really concerned about.

gtwitch in wyoming

 

[SAndreasen]

You are going to have a tiny bit of particles in there with that many miles on the oil . sometimes there is a magnet on the PTO cover I go to the hardware store and get a rectangular magnet they usually come in two packs then I just stick them inside the transmission on the bottom . Its hard to get all oil out of the PTO cover well you just can't so what I did was drilled and tapped a 1/4 inch pipe plug on the bottom of the case and about an inch ahead of where the transfer case and transmission join makes changing oil a ten minute job . I've got one trany that doesn't have a drain so take the cover clear off and use a suction gun to get the oil out this works pretty good if you dont want to drill and tap the case

 

[CM_Guest]

As SAndreasen said, some metal in the oil is normal. Especially in gear boxes where there is lots of gear-to-gear contact, but even in an engine. Ever seen the "paste" on the drain plug of your Cummins? The only way to use metal in the oil to determine a failure point is if there is a LOT of it and the component has obviously failed OR by performing oil scans on an ongoing basis. Like I said, I'm not the correct police and I won't tell anyone else what to do with his truck, but I put Castrol Syntorq in my NV4500 and changed it according to factory recommendations. Frequent changes with "lower-quality" lubricants is usually better than rolling the dice running supposedly "superior" lubricants long-term. It doesn't matter how good Amsoil or any other super lube is. If you're not changing it periodically that normal wear material is staying inside the component instead of being drained out.

 

[CM_Guest]

I'd recommend flushing the clutch hydraulic system. Normal brake fluid shouldn't boil at low temps like that but brake fluid is hygroscopic and attracts moisture. There could be a substantial amount of moisture in the clutch hydraulic fluid adding to that problem.

 

[gtwitch]

CJ, Ironically, My son (service manager at a dealership) and I had this discussion about the DOT3 fluid in the clutch hydraulic system and the possible moisture just last evening. I am also in the process of putting a 1/4 pipe plug in the bottom of my case while I have it drained. I also have a magnet in my hand to place on the inner side of the PTO cover, sop if the Transmission hangs together, I should be OK for a couple more years. I'll keep the post going.

Thanks
gtwitch in wyoming

 

[gtwitch]

Ready to put the PTO covers and the Fast cooler on the trans and fill from the top. Will start with 8 pints and then more as required to get just over full. I only have one Fast cooler on the drivers (left) side of the trans and I think this will take about 10 pints or so to just overfill about 1/2". The Magnet on the inside of the PTO cover (left) and the magnet on the dip stick in the Fast cooler both had ferrous material, some but not a large amount in my eyes for the miles on the oil, but more on the pto magnet than when I had the trans out at 100K if I remember correctly. I have another magnet to go on the inside of the right side cover wo will put that in. I guess I will see if the trans hangs together in the next 6 months or so.

gtwitch in wyoming

 

[SAndreasen]

Did you get it up and running ?

 

[Vaughn MacKenzie]

As far as running temps go, I have a trans temp gauge on my '96 5-speed and what I generally see it stabilize at is 120F running around town, and 150F on the highway after 30-45 minutes. In hot 100+ weather it will run 180-190. Towing moderate loads it runs 180-210. Once when it was fairly warm and very windy towing my small travel tailer it soared to almost 240. I run Amsoil but don't have coolers, fill it a bit above factory level and it doesn't leak. I change it every 50K and the magnet has minimal metallic residue and the oil is pretty clear. I rebuilt the trans at 370K and it has 482,600 on it now.

 

[gtwitch]

Update!! I got it all back together and filled (overfilled 1 pint) and have driven it for about 150 miles local to the landfill and other and it shifts OK and is noisey (if you can hear it over the Cummins) in 3rd and 5th for sure. I am looking for a not so used NV4500 or a rebuilt. I found a rebuilt in the Denver area where my son lives (so no shipping either way) but I may have to just trade it. Hate go get rid of a vehicle that I know every little quirk and the Cummins will still be running great at 500k. I guess it will soon be decision time for the 99 that has a lot of rust.

gtwitch in wyoming

 

[SAndreasen]

Man that really sucks bad I think I would get a rebuilt trans I don't think I would dare go the used route . Guess if you wanted to trade it dump a quart of Lucas in er and send it down the road .