2nd Gen Non-Engine/Transmission Dana 80 diff fluid extremely dirty. What should I look for?

[jgillott]

I just completed the first diff fluid change on my '01 at 33500 miles. I havn't towed heavy or often with this truck. There has not been any indication of a problem with the diff. On all of my other vehicles, I have done the first change between 12-15K. Every time, the diff fluid looked good and clean. So on this truck, I figured that I would wait until now. Boy was I wrong!



With that said, the fluid came out thick and dirty. It almost looks and feels like chocolate syrup. The fluid doesn't smell burnt, but there was some small metal shavings on the plug.



Is this what any of you are seeing on a 30+K change interval? Does this sound like fluid that could have been contaminated? Is this an indicator of a specific failure?



Thanks in advance



Justin

 

[dresslered]

What you are probably seeing is normal for that kind of mileage on the OEM fluid. I see that you have a LSD, so you will get some extra wear from the clutch plates. I would highly recommend the Mag-Hytec rear end cover. It will add more capacity, has better cooling, has a drain plug so you can easily change the fluid (without having to remove the cover), and has a magnetic dip stick to grab any suspended metal filings as well. An excellent fluid to use is the LE607. It is a 90W mono grade but has excellent performance characteristics (don't forget to add the friction modifier). It too, is available from Mag-Hytec. If you tow really heavy, or live in extreme environments, then you might look into the multi-grade stuff.

 

[Gary - K7GLD]

Mine was dirty after about 5000 miles - the wearing-in of the limited-slip clutches CAN shed lots of debris. But since that first change, the lube seems to be staying quite clean...

 

[DLBurns]

I would highly recommend the Mag-Hytec rear end cover. It will add more capacity, has better cooling, has a drain plug so you can easily change the fluid





I have the Mag HyTek diff cover and DD trans pan... if you plan on using the drain plug on these things I would highly suggest taking it out and putting some oil on the o-ring and anti seize on the threads of the plug other wise you will NEVER get the damn thing off!!!!

I brole a Craftsmen allen socket trying to get the plug out of my transmission pan, tried everything next to dynamite to get it off, needless to say that it is still on and I am highly PO'd that it doesn't work as advertised. My next trans fluid change it will come off one way or the other, if I damage the pan then will just see how good Jerry's PR skills are!!!

 

[jgillott]

Thanks for the replys all. I'm happy to hear that what I'm seeing isn't out of the ordinary for a 30k interval. I can't tell you how it scared me to see it that dirty. I'm certainly not going to let it go quite as long next time... ... .



Thanks



Justin

 

[dresslered]

Justin, as Gary mentioned, the first change is usually the worst. I routingly check mine using the dipstick, and it is still looking good after 48,000 miles. I'll probably change it out shortly just so that I can sleep at night. On a side note, when you are doing the drain, you might want to alternately lift the truck on each side. This will allow the oil to drain out of the axle tubes.



Buff, sorry to hear about the drain plug. I have a MOMO gear shift knob that has permanently fused to the shift lever in my BMW. Aluminum bonds to itself over time. What you suggest is probably very wise. On my Mag-Hytek, I didn't install it very tight, and from time to time check to make sure that it still turns. I think that if you get a little oil on the threads, you won't have a problem.

 

[JJW_ND]

Change more early on and less with more miles.

What I have found (based on oil analysis of differential oil I changed) is the first few changes look bad, test poor and should occur pretty close. I would change the second or third oil change (12 - 20K miles then again 20K down the road). After that you should make 30 - 40 and after 100K every 50K is probably fine. This is based on a trucks that was pulled hard. One running empty could go to longer changes earlier.



I have found that good looking oil still tests poorly (high TAN... . acid), conversely, I have see that brown surupy looking stuff test out pretty good (good for continued use).



jjw

ND

 

[DLBurns]

I have 2 years and 15,000 miles on my Amsoil synthetic diff lube.

How long will this stuff last? Most of the miles on the truck are towing miles??



David, I was highly ****** over that drain plug... they should leave it out when they ship it to you and have you install it the right way upon delivery!!

Hope I don't have the same problem with the diff cover

 

[dresslered]

Buff, I'm sorry but even though I recognize your login name, I can't place a face to it. Are you a memeber of the San Jose Ramrunner's (I'm guessing so)? Anyway, we have a couple of people (at least one machinist) that might be able to suggest and/or help you out with the removal of your stuck plug. I'm one of the odd-balls that has to take every new toy completely apart once I get it. This probably accounts for the reason my plug is still removable.

 

[DLBurns]

Buff, I'm sorry but even though I recognize your login name, I can't place a face to it. Are you a memeber of the San Jose Ramrunner's (I'm guessing so)? Anyway, we have a couple of people (at least one machinist) that might be able to suggest and/or help you out with the removal of your stuck plug. I'm one of the odd-balls that has to take every new toy completely apart once I get it. This probably accounts for the reason my plug is still removable.

Yes David I am a member of the Ramrunners club, I don't believe that we have ever been formally introduced. I really don't know a damn thing diesels so I have been depending on Blair, Chris and Cliff to steer me in the proper direction. I have met a few of the other folks in our club... bunch of great guys!!! Hoping we can schedule some mild bombing parties before winter sets in. I would really like to see us do some of the things the NW Bombers do, they have a great group up there!!

As for the plug (s) I'm gonna get that damn thing out if it's the last thing I do... . it may result in a new pan but the plug WILL be out.

Hope to finally meet you in person at the next meeting

Dave

 

[dresslered]

You're definitely hanging out with the right guys. I too wish that the club would become a little more active than it has been (no longer have Nowel to spice things up). It definetely has the membership numbers though. Unfortunately, it seems that with the layoffs in the valley and now with a change in the meeting place, the club is a little fractured right now. BOMBing sessions would be fun.

 

[DLBurns]

I know what you mean regarding the economy here, been a tough road for some folks.

I would like to see the club get together at least once every couple of months and do a BBQ and mild bombing party... hell if we just changed oil and filters at least we would be doing something. I do know that it would not be fair to the "gearheads" in the club to ask them to take on all of the larger jobs... maybe just act as coach so us novices can learn more about our trucks. Blair has been of graeat help to me in flattening out the learning curve. By golly he showed me what a hog ring was the other day? I had no idea!

 

[dresslered]

Did you know that Blair was the club's treasurer? Did you also notice that he always has all the newest toys on his truck. Coincidence?