2nd Gen Non-Engine/Transmission Dana 80 Rear Axle---Bad Bearing

[Shelby Griggs]

In a thread in June https://www.turbodieselregister.com/forums/24-valve-engine-transmission-1998-5-2002/213721-nv5600-rebuilder-blumenthal-standard-transmission.html I mentioned a noise I thought was the NV5600 calling for a rebuild. It turns out the noise was actually from the Dana 80, I just got done having a shop tear down the rear axle and replace the bearings and seals. The noise was coming from the bearing pictured below. 222,462 total miles, since the initial factory oil I have ran Amsoil for the entire time with about 30K changes, the shop put Schaefers back in, since that is what they had. I can't necessarily blame the Amsoil, but that kind of wear seems excessive while using expensive oil with regular changes. Note also that the inner race is cracked. $809 later I should be good for 200K again! I should note that the noise was pretty minimal but getting louder, the shop said they wouldn't even of been concerned by the noise alone, BUT it was not normal to me and I am the sole driver so it was painfully obvious something wasn't right.



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[fest3er]

If you have the parts, contact Amsoil. While they will probably say, in essence, 'not our fault', I think they will also tell you what did cause the failure.

Just a guess here, but perhaps Amsoil lube is the reason you got that many miles from it. My '98 has had one or more noisy bearings for 6-10 years. Lately, it gets really noisy in the frigid winter, loud enough to drown out the engine.

 

[kenny61]

Which bearing was it?

 

[CumminsPower98]

I had 358k on mine (lots of towing) when I first pulled the carrier out to check the bearings and preload. Well there was no preload it seems from the factory so this let the unit tilt side ways a tiny bit under power and was starting to put tiny pits on the ends of some rollers and a slight scar around the outer edge of the races. Very minor but I replaced the carrier bearings and set the preload up correctly and went on. I was using Amsoil Sever Gear 75/140 and had been for most of its life and I was running 100k intervals, which was working great. Later on when I quit driving OTR I decided to drop the heavy oil and put lighter in for less drag driving around empty. It was way before change time but I did it anyway and I'm sure glad I did. I felt for backlash just to see how things were doing and there was none!! Pulled the carrier out and the right bearing had gone to pieces enough to allow it to shift right removing all backlash. It had been only about 29k miles since the new bearings and I know I set it up correctly as I have done many rear ends. I got new bearings under warranty and put it back together with all new bearings this time since all that metal had circulated into the pinion bearings. The odd things is I never heard a sound out of it other than one little "chuck", which at the time I had no idea what it was but it scared me.



So in your case I would be highly surprised if it was oil related. Bad set of bearings maybe? Did you haul HUGE loads a lot? Or maybe it wasn't setup correctly from the factory. All it takes is one roller to start flaking and more will be damaged and so on until they completely die.



This picture is of my "new" bearing that failed.

 

[SRath]

Wow! This is a bit disturbing. I have always considered the rearend in my pickup to be nearly bulletproof. Overkill even. The massive D80 with bearing failures even with Amsoil? I would believe the bearings are subpar before I would the oil. Bearings are not what they used to be. Even the most trusted names are now made in 3rd world countries. Probably by peasants working in dirt-floored factories. Definitely at the lowest possible cost.



Our semi tractors at work have huge Eaton axles. They have a tendency to shear a cheap, tiny 1/4" retainer bolt that then leads to a wobbly change in tooth engagement and, quickly, catastrophic failure. I felt the subtle harmonic immediately when it happened to my tractor, like a slight rhythmic shiver or rumble under coast that simply had never been there before, and limped it straight, and gently (bobtail), to the shop only a few miles away. That saved the axle, but if it had not been under warranty the repair would have been very expensive nonetheless.



No one had ever caught it that early before, according to the mechanics, who knew exactly what it was when I told them what I felt. Amazingly, they had never issued a warning bulletin to the fleet drivers about this problem since other drivers reported feeling and hearing nothing unusual before theirs went out. Given the scale of noise and vibration in an 18-wheeler, that is understandable. Given the even worse tire-howling, paint-shaker environment that has been my Dodge as the frontend has deteriorated, I would never be able to pick it out.



As for these Dana axles, I wonder what the preventative answer is for the average owner? Few of us are as differential-experienced as Mark, and even he had trouble. I wish they were built like the GM Corporate 14 bolt 10 1/2 inch ring gear rearend. That is one very well-designed unit. Superior in every way to the comparably sized Dana 70. More pinion support; much easier to setup with adjusting nuts and retainers instead of shims; and the least expensive Detroit Locker drops right in the stock open carrier. If my D80 ever shucks, that's what's going under my Dodge.

 

[HBarlow]

I used whatever brand name synthetic differential fluid was offered at Autozone for 325,000 miles on my '01 with heavy towing use. I changed the differential fluid at 50k intervals using a Mag-Hytec cover. No noises, no problems.

Anyone who owns a Gen III Ram knows that Dodge replaced the Dana rear ends with AAM units. The owner's manual of Gen III Rams calls for 15k mile service. I added a Mag-Hytec cover in my '06 when the truck was new and used Autozone synthetic differential lubes and a 50k mile service interval. Likewise, no noises, no problems. I sold the truck at 230k miles.

Can someone tell me again... ... . what is the advantage of Amsoil?

 

[Shelby Griggs]

The failed bearing was one of the differential carrier bearings, not sure if it was the left or right. I agree this was probably not oil related, but probably a bad bearing or bad set up from the factory, and once a roller starts flaking it is all down hill. The OEM bearing was a KOYO brand, made in Japan.



I didn't see the replacement bearings, but the shop said they were Timken, hopefully they weren't made in China!



I don't run super heavy weights, about 8000-8500 on the truck at ALL times and when towing I am about 12000 CGVW, certainly not the weights some folks run.



I have had a Mag-Hytec cover for most of the time, probably installed around 60K (too lazy to look at my records this morning!).



All of my oil changes have produced pretty nasty oil with a fair amount of fuzz on the magnets, never any big chunks, and what looked to be water contamination. I have never had the truck in water deep enough to submerge the axle, maybe just condensation?



Anyway, obviously even with regular maintenance Dana 80 failures do happen as evidenced by Mark's failure and mine, I no longer think they are bulletproof. I did read someplace, maybe here on the TDR that Dana axle rebuilds aren't that uncommon at around 200K, maybe there is a reason Dodge went to AAM axles?



SHG

 

[CumminsPower98]

I'm not going to get into an oil war here. Amsoil of course publishes oil studies that are supposedly done by an independent lab that show their oil to be superior. It was just a personal choice for me and I'm sure many other synthetics are great as well. I do believe synthetics have an advantage over conventional in most cases. People probably think 100k change interval is crazy but even at that extended mileage my oil came out looking quite nice and I almost felt bad throwing it away. No I never had it analyzed but my parts showed that it was doing its job. I was towing 45% of those miles with the heaviest being about 22k GCW but most were much less.

I personally feel that many of these failures are probably due to less than perfect bearings and or improper setup. With that said I must say I'm not an expert. I have rebuilt a fair number of differentials but its not a daily thing for me like if I was working a differential shop. Like I said before mine was loose from the start but still held up well for 358k and even then would have gone longer as the damage was minimal. These D80s are not indestructible for sure but with reasonable loads along with proper setup they are a very strong unit. Start pulling loads not designed for the truck with an uprated engine and without a doubt you start raising the possibility of problems at some point down the road.

The best thing a person can do is just keep an eye on things. Feel for backlash in the pinion when under there and make sure there is no side movement in the pinion. When the cover is off for an oil change get a pry bar in there and see if you can move the carrier side to side and of course check for metal in the oil. If you really want to make sure things are good pull the carrier out. If it just drops out like mine did its not setup correctly and needs more shimming. You should have to pry it out. This is just simple stuff to check that can save you a lot in the future if you find something before it gets bad.

My cousin's '97 had the left carrier bearing loosen up on the carrier, which caused the shim pack to get smashed out and the whole thing become loose. I had to put a new carrier in and a full set of bearings. His pinion was also loose. He has about 300 RWHP and was hauling as much as 36k at times (wrecked cars on 58 foot goose neck). He also completely stripped the gears off the the input and or counter shaft (I didn't see this, just know it had direct only) in his NV4500 while hauling cars. He now has the 5600.

Here is a picture of the worst of the 358k carrier bearings out of mine. Most rollers showed no sign of damage. In this small picture its hard to see but there are really tiny pits on the outer tips of those rollers facing away from the race behind.

 

[DGamelin]

Dodge change to the AAM for a better price. I have AAM axles in my 04 and would take a dana over them any time. At 55k it used up a posi, I am at 87k and it is on it,s way out again. I just ordered a open carry for it. The posi are to munch money to keep buying them every 55k. I do tow heavy and the truck has a trailer on it 90% of the time. In the spring I am going to start looking for a C&C and I am thinking of a 4500 just for the rear dana. I have also put 3 front pinion seals in, and rear axle seals to.

I think the quality of bearings are getting very sad. What is out there could make any thing look bad.



_________________________

93 250 2wd xc 354 auto 264k

04. 5 3500 4wd cc dully 373 6speed 87k

 

[fest3er]

... maybe there is a reason Dodge went to AAM axles?



SHG

IIRC, Chrysler switched to AAM after Dana refused to make design changes to quiet down their differentials. Apparently Jeeps had become quiet enough for occupants to hear the normally noisy diff gears and complain.