TSB 03-001-04 REV. A

http://www.klenger.net/dodge/3rd-gen...1-04-rev-a.pdf

My chnage interval is 30k and I use AMSOIL and retail price is $13.10 but since I'm a dealer I get it cheaper. I also don't change mine but every 60k because AMSOIL has a longer drain interval.[laugh]

LOL......must be one of them guys that pays 100 bucks for the dealer to change the fuel filter. Nothing wrong at all with not wasting money if you dont have to.

I haven't seen any TSB about going with 75w-140 if Towing heavy. According to all the stuff I've seen it says DO NOT USE any modifiers and NOT to use 75w-140. If anyone has sen different then please let me know.[dummy]

I think there was a bulletin stating this, but it was referring to 1500 trucks with the 9 1/4 rear axle.

I just changed the diff oil frt and rear at 75000, the old oil was a golden color and you could see thru it as it was draining. I was expecting it to be dark and have the typical gear oil smell. I replaced it with Mobil 1 75W90 synthetic. Based on the condition of the factory fill oil Id say 15K service is overkill.

I change the rear diff every 30K and front diff every 60K, both with Mobil 1 75W90. Oil always drains out looking like new. I'm about 7500 lbs unloaded, and usually 17K-18K lbs GCW when towing, and I tow about 20% of the time. Currently at 160K miles on the truck.

Torco has GL-6 oil. 85-140. I use it and I am not going to change it every 15k miles.
Side note,,, Had the front pinion seal replaced under warranty at a good dealership. Got a call from them saying that the front diff oil was milky, looks like water in oil. I had just checked it and it was clear. I just said thanks I would change it as to not pi$$ them off. Were they just trying to re-coop the cost of the seal? or was mechanic just trying to make a few bucks on a slow day??

I am just at 100k miles. I have changed the axle lube 3 times and each time with a quality grade dino gear oil. Say what you want but it is still just a simple gear box. I feel synthetic in anything is overpriced and overtalked. Although I do stick with ATF+4 as the 48RE is not a simple gear box.

I changed both my axles prior to the first recommended timeframe of 15K. I sent in an oil sample, and the results were terrible. Basically the diff oil had little to no visconsity, the entire report suggested that the factory oil was garbage, same stuff the dealerships sell you, so I will NOT use the oil found at the dealerships.

I called AAM directly to discuss this subject, the person I spoke with told me that I should be running the 90w-140 due to my driving conditions, at the least, use the 90w110 available from Amsoil. They also told me to change both axles at the same time AND use the same weight oil in both.

I put in Amsoil 90w140, I tow, tow heavy, drive in hot conditions with high road temps, so I wanted to be sure to use a good quality synthetic with a track record. At 15K on the Amsoil, I sent in a sample, the lab told me I could easily go an nother 15K, fluid was like new. At 30K on the Amsoil, I sent in another sample, and once again I got a great report back, told I could easily go an nother 15K. At 45K on the Amsoil I sent in another sample, got another positive report and was told the oil was fine. I decided to change it anyway, this time I put in the 90w110, I plan to sample this oil the same as I did before. I will be able to see if the 90w-110 will hold up as well as the 90w-140 over the same kind of mileage.

There was a bulletin about using the 90w-140 in the diffs, it pertained to those who DO run in hot climates with hot roads, it was recommended by AAM that the people use the 90w-110 at minimum and those who tow heavy and hot climate go to the 90w-140. I believe it is Carson Dodge that actually put that bulletin up on there website.



CD

Man, don't any of you read the previous posts in this thread? I posted the link to the TSB.

X2 I am running dino also. When I went from 3.73s to 4.10s the shop that did the work said they would not waranty the gears if i went with synthetic, So its been dino for about 100K.

1] Are you sure that the Dodge and GM axles are spec'd exactly alike? Absolutely no differences? "Internet Wisdom" sez Dodge spec'd 3X life bearings and GM 2x. And that the published maintenance schedules of GM & Dodge are exactly alike, again, no differences? It's unlikely, so the comparison is worthless.

Being gamed over lower warranty costs? I've not ever heard or read that frequent fluid changes were EVER a bad idea so long as all parameters are met. Of course they want to keep costs low.

2] If someone goes to the trouble of fluid analysis with a certified lab, not just some tech at a service house, then, yes, maybe changes are in order depending on the trend of a number of analyses. And any published information from the manufacturer regarding changes for conditions. should be brought to bear. And this was not within the scope of the OP.

The original post took into account ONLY the difference between cheap stuff off the shelf (meeting spec?) and paying the premium for synthetic (again, meeting Mopar spec?). There is no cost savings in that approach. Thus my response like a jerk, for which I apologize.

Changing often -- with who-cares-what-it-costs MOPAR fluid -- is a default, bulletproof choice. Worrying over a few dollars, ain't. The change itself is easy to do (easier than an engine oil change if for fluid volume alone and no filter). The labor cost is a different question altogether.

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No worries. Having been on the internet for over 20 years now, I learned a long time ago that things often "sound" different when read than they would in person.

I think what I've taken out of the posts here plus other things I've found looking around the internet over the past few days is that 15K with synthetic is most likely a big overkill, but there is no hard evidence one way or the other. I'll probably move up to 25K since that's how I've always done it anyway. I might even extend the front to 50K. Regardless, though, I'm going to do some oil analysis. Heck, if I'm going to do that, I might even try dino oil at some point, but I might wait until I have a temperature gauge on the differential.

What I can't really understand is how both dino and synthetic can both be GL-5. One might think that the synthetic just simply exceeds the GL-5 spec by a wide margin while the dino oil maybe only slight exceeds it. But, I would think that GL-5 is GL-5 when specifying what the equipment needs.

One thing that I do know for sure is that I'm not buying any more Royal Purple. I can get Redline or Valvoline synthetic for around $11 a quart. Less if I get RL in a gallon jug.

If you want to really do fluids analysis, then I can happily recommend this man:

http://www.dysonanalysis.com

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