2nd Gen Non-Engine/Transmission Metal shavings on magnet inside rear differential cover

[T.Shaffer]

After poking around the TDR website, I decided that, although not urgent, at 70K miles it was probably time to change the oil in the differentials on my '97 2500 4x4. I did the rear first, knowing from the TDR threads on the subject that it would likely be the dirtiest and most in need of changing.



So I popped the cover and the oil wasn't too bad but dirty enough that I didn't regret opening up the "punkin" to change it - at least until I got a look at the magnet on the inside next to the fill plug. There was the usual "mud" that you expect but the metal shavings were a different matter.



Being ignorant of the true significance of this, I stopped the project and took the undisturbed differential cover over to some friends of mine who happen to have a 4x4 shop. Ed Holbrook (Holbrook Specialties, Gladstone, OR) casually glanced at the magnet and informed me that the shavings are a result of the left carrier bearing wearing out and what I was seeing was what was left of the shim(s). He also said that he regularly advises owners with 100K or so to not be surprised when they find the same thing. He's replaced tons of them and will be doing mine at the end of the week.



Like timing chains in Chev S-10's with the 4. 3L V-6 or the front brakes on trucks like mine, according to Ed this is just one of those things to expect and that I should be grateful that I was doing routine maintenance instead of roadside emergency repairs!



This is probably old hat to many of you but not to me. I shot some photos of the evil stuff still on the magnet in case someone else discovers it and wonders if it's normal wear. Apparently they're too big to include with this posting so if you want to see 'em, email me and I'll send them along.

 

[Matt42]

Is this a Dana 70 or 80 pumpkin?

 

[T.Shaffer]

It's a Dana 70 - I thought the 80's only came with the 3500's.



TS

 

[JGheen]

I have heard and seen the 2500s w/ the manual trannys come with the 80 rear end. Wonder if that was an option from the factory?

 

[cumminspwr01]

Mine came factory with an 80 in it. I thought the only 2nd gen trucks that came with the 70 s where automatics

 

[CumminsPuller]

Out of curiosity, what does it cost to have a rearend rebuilt? I have 240K on the truck and tow heavy everyday. Mine is in need of a rebuild and have no clue as to hom much something like this should cost.



Jason

 

[TPlasek]

Bearing and shim kit cost about $100-$125 and around here it is another $150 to have those installed, if you take them only the axle. I have no idea what it would cost to do in the truck. I have rebuilt my dana 70 and 60 combo in my jeep a few times myself. The hardest part is getting the pinion bearing off. I finally broke down and purchased the proper tool for doing this.

 

[2broke2smoke]

a friend of mine had 3 first gen cummins' (surveying business)... each sold with 300k+ he never changed rear diff ... except to top off with brake work



i sold my '91 with 275k ... oversized tires (35-42") from 75k on ... changed fluid 3 times



brother in law still has his '89 dually flatbed with 240k ... he bought it at 100k ... just tops off if needed



none of these trucks ever needed diff rebuilds



around here the dana 70's and 80's are considered "no maintenance" parts



i've been around diesels since 1990 (surveying and in the oil and gas industry) and have never heard anyone mention 100k mile rebuilds for dana axles ... or any other "one ton" axles



have we just been lucky?



or do you guys tow heavy?

 

[Gary - K7GLD]

My RVing buddy is having the Dana 80 in his '99 Ford PS rebuilt as I type this - very noisy, whine and howl (the rearend, not my bud!)(THAT will come when he gets the bill!)



He has somewhere over 70K miles, and tows heavy - does little maintenance on the rearend or transmission, and will now have rebuilt or replaced BOTH of them,,,

 

[RabidRam]

Originally posted by CumminsPuller

Out of curiosity, what does it cost to have a rearend rebuilt? I have 240K on the truck and tow heavy everyday. Mine is in need of a rebuild and have no clue as to hom much something like this should cost.



Jason

Due to my own stupidity and trying to show off for some friends, I ended up having to rebuild my Dana 80 LS rear with only about 100K on it. At the time, I had no idea what the TDR was (and didn't know any better), so I took it to the dealer. The complete bill for rebuild, labor, parts, etc... was a tick under $3G. Yeah, I was like :--) Sad thing is I think the rebuild is going south on me, too. Detroit, here I come!



Dave

 

[CumminsPuller]

Originally posted by 2broke2smoke

have we just been lucky?



or do you guys tow heavy?

There was an article in a past issue of TDR that talked about haveing rebuilds done if towing heavy... ... ..... How shims wear out and can sometimes fall out... . Don't quote me, just trying to remember. Mine has that popping noise while I turn. It started after the last fluid change. I had never had to add the LS Additive, but after the last fluid change I had the popping noise while turning. I added some and it did not help(not sure if I added enough or not)..... Not sure if I should waste my on a fluid change again and smoe more additive and try and do it correctly or not... .....



Jason

 

[tgrfan2]

Dana 70

My 95 auto CTD just turned 200k with no rear end problems yet. My 98 auto with limited slip trashed the left carrier bearing at 80K. I never have serviced the 95 rear, but religiously serviced the 98 even using the Mopar oil and additive. Don't let one go and keep checking for shiny debris on the magnet. Mine tore up on a trip at Christmas last year. The race turned ruining the housing which is $1400+ by itself! I tried for three weeks to find a used one with no luck. I have to say the TT I was pulling then was extremely front heavy, but the 95 had pulled it more miles. I've got a feeling the LS is part of the problem. I had a tech at the local GMC dealer rebuild it for me and so far (45k) so good. He said he did about three a week, but usually the race did not turn and destroy the housing. I have run Castrol synthetic since the rebuild.

 

[Bob4x4]

The carrier bearing failures are not rare on the Dana 70's. A diff shop in Anaheim Ca(Unitrax) has built a tool to save the housings that have been damaged.



Bob

 

[Extreme1]

Originally posted by CumminsPuller

Mine has that popping noise while I turn. It started after the last fluid change. I had never had to add the LS Additive, but after the last fluid change I had the popping noise while turning. I added some and it did not help(not sure if I added enough or not).....

Jason,



Add the Mopar LS additive 1 ounce at a time until it stops the popping. Go out to a parking lot and do figure a couple dozen 8's to work it in.



The Mopar brand is the best stuff available for our applications.

 

[CumminsPuller]

Extreme 1,



I will give it a shot and see if it stops popping. I guess dropping money on some fluid is with rather than paying for a rebuild.



Jason

 

[Dane]

I decided that, although not urgent, at 70K miles it was probably time to change the oil in the differentials

A Dana 70 or 80 will last pretty much forever if you change the oil every 30K miles or 10K miles if you tow most of the time. Changing the oil is a lot cheaper and less work than having the diff rebuilt.



You cannot tell by looking at oil that it is "OK" By the time it "looks" bad the damage is done...

 

[T.Shaffer]

I bought my truck used in 1998; it had 27K on it and had been used for frequent trips to Central Washington and back hauling a whopping big horse trailer. I bought it to tow a 33' fifth wheel but during only the second outing, my wife and I both agreed we hated the damned fifth wheel and went back to a motor home (with a Cummins, of course). BUT we liked the pickup so much we kept it although it's a touch heavy to pull behind the coach.



My point is that since I've had the truck it has pulled a variety of cars and my tractor on my 16' flatbed but nothing I would consider "heavy" hauling. I detected no symptoms of the bearing going south - I'm just glad I decided to change the fluid and discovered it!



I'll let you know what it sets me back - it will be in good hands at Holbrook's and they'll be fair about the price. After all, Ed bought a 1st Gen Dodge last year and I've been loaning him my TDR's ever since!



Interesting responses - it never ceases to amaze me the amount of knowledge and experience that is brought to this web site.



TS

 

[T.Shaffer]

Well, I'm $306 poorer now but have fresh bearings and shims. I'm not sure I understood correctly but I think I was told that the area in which the bearing race is seated was also knurled since they don't fit very snugly otherwise. The race they took out of the left side was still intact although, judging by the discoloration, clearly had gotten pretty hot. There was about a shim and a half left too.



Now, what else haven't I checked lately?

 

[CNeuman]

Jason,



Would be curious to hear what you determine about the "popping". My buddy's 96 3500 just starting popping while turning under heavy load. We were coming from Oklahoma to California pulling a 6-horse when we noticed it in a truck stop. Sounds like a bell being banged on every second or two. Scary! Truck was OK when not towing or going straight.



I assumed it was some kind of LS problem related to outside tire turning faster than inside tire.



Thanks,



Chris

 

[Kirwin]

For the record

The 97 manual transmission equipped trucks had Dana 80s. The Dana 80 is very tough unit. They do require oil changes and quality and quantity of oil is important for long service life, especially during heavy trailer towing applications. Dodge recommends the 75W-140 synthetic oil for trailer towing. Its pricey from Dodge at over $20/quart. I am of the personal opinion that these failures that we see are from the temperatures that these differentials reach under severe service trailer towing. I have personally seen over 230 F in my Dana 80 and thats with a Mag-Hytec cover and nearly 8 quarts of 75W-140 synthetic oil back there. If the housing looses enough the bearing will spin. The 70s are also a good unit but they are not quite as HD as the 80s and need rebuilding about 120-150K. The first time I changed my rear differential oil in my Dana 80 was at about 11K and there were several large metal chips in the housing along with the normal gray very fine metal "silt" on the inside of the housing. I figured the chips were from machining the axle tubes. Next time there was next to nothing at about 19K later. I have serviced the rear differential about every 20 K and so far no problems and I tow heavy but I'm not too far out of Dodges specs. :-laf



CumminsPuller, CNeuman, if its been a while, change your oil in the rear differential and start out with about 2 bottles of Mopar's limited slip additive. It may take more (or less, but more won't hurt if you don't get excessive) then take it out and try it. Before you add more be sure to give the new oil a chance to work its way into the friction clutches in the rear end. Figure eights are good for this. I get this popping noise after traveling on the interstate (in a straight line) for long periods and then when I get off on the first turn, thats when I hear the popping sound. As long as it goes away I've never worried about it. All the above IMHO. Ken Irwin