Differential fluid thoughts/recommendations...

My 1500 manual says 75w140 for rear.

Mike LeClair wrote:
This is nothing more than the product of the power of advertising and perhaps preying on folks with too much money in their pockets? Do you really think that the OP is of the ilk who change their own rear end/differential fluids? The engineers who designed the truck know exactly how much oil is needed for cooling even under the most arduous of conditions. Do you really think that the OP is going to monitor the differential temperatures of his rig? You would be lucky if an owner pays attention to or knows what an EGT is! There is plenty wrong with more if the more is only to pad the wallets of the geniuses who make us believe that we just gotta have it.

BTW OP, are you SURE that the spec for the front differential is ATF+4?

Cheers!

Mike

The ATF+4 was actually the transfer case, not the front differential.
My mistake.

However you assume too much. I am rather anal about keeping an eye on my engine. I use an EDGE Insight and constantly watch intake air temp, coolant temp, trans temp, pre-turbine exhaust gas temp, post turbine gas temp, DPF temp, DPF pressure, boost, HP... seeing a sudden increase in my exhaust temp saved me once. This may be over kill but I'd rather know than not.

If I can get temps out of the differential I will, but only if I can integrate it into the Insight. My brother-in-law is an ASE Master Mechanic and has owned Ram diesels for decades. He recommended sticking with the 75W-90 but I thought I'd ask people who consistently tow fifth wheels.

Didn't think what seemed a simple question would get such an emotional response from some folks.

This is an article on building up a HD towing rear axle in a Ford truck that I bookmarked several years ago when I had a '95 F350. I've always thought it had some pretty good info in it that they've backed up by real world testing.

Note the gauge verified temperature reduction with the Mag Hytech diff cover. Also note which non-OEM oil produced the largest reduction in differential temperature (not Amzoil, although Amzoil lowered the temp a respectable amount as well).

FourWheeler HD Towing Axle Article

:):)

Grit dog wrote:
Again I'm sure my truck would still be on the road if I used another brand as well.

While everybody else's is home in the garage.

I just changed the differential fluids and transfer case on my 2012 Silverado 2500HD.
I used Mobil 1 75-90 Full synthetic, I have 35000 on the clock and I gotta say that I am noticing a 1 to 1.5 MPG increase! Truck actually feels like it has less rolling resistance. I used Valvoline full synthetic in the transfer case..

djgodden wrote:

Mike LeClair wrote:
This is nothing more than the product of the power of advertising and perhaps preying on folks with too much money in their pockets? Do you really think that the OP is of the ilk who change their own rear end/differential fluids? The engineers who designed the truck know exactly how much oil is needed for cooling even under the most arduous of conditions. Do you really think that the OP is going to monitor the differential temperatures of his rig? You would be lucky if an owner pays attention to or knows what an EGT is! There is plenty wrong with more if the more is only to pad the wallets of the geniuses who make us believe that we just gotta have it.

BTW OP, are you SURE that the spec for the front differential is ATF+4?

Cheers!

Mike

The ATF+4 was actually the transfer case, not the front differential.
My mistake.

However you assume too much. I am rather anal about keeping an eye on my engine. I use an EDGE Insight and constantly watch intake air temp, coolant temp, trans temp, pre-turbine exhaust gas temp, post turbine gas temp, DPF temp, DPF pressure, boost, HP... seeing a sudden increase in my exhaust temp saved me once. This may be over kill but I'd rather know than not.

If I can get temps out of the differential I will, but only if I can integrate it into the Insight. My brother-in-law is an ASE Master Mechanic and has owned Ram diesels for decades. He recommended sticking with the 75W-90 but I thought I'd ask people who consistently tow fifth wheels.

Didn't think what seemed a simple question would get such an emotional response from some folks.

An emotional response was not my intent. I am as anal as yourself and many others when it comes to my vehicles. I have an Edge Juice with Attitude and I monitor everything I can, within reason. I do all of my own wrenching on my truck, car, RV and motorcycle, mostly for the economics of saving labour costs and the satisfaction of investing my own sweat and blood into my stable, as meager and simple as it is. I am not trying to goad you into a rebuttal nor do I challenge your decisions - does your BIL use any of the aftermarket diff covers that are on the market? Stick with the 75W-90 oil in your pumpkins, change it regularly if you tow a lot. Check the diff fluid levels at every oil change and don't worry about the temps of your diffs unless, of course, you are towing way over your weight limits, which is a whole other chapter of contention! :B

Cheers!

Mike

So the stock AAM differentials in OEM form from Chrysler aren't capable of a long life of intended service without special mail order oil and covers?

Is there any reason why switching to 75W-140 would not be advised versus 75W-90?

I'm not wondering if its necessary. Just if its not advisable.

lawnspecialties wrote:
Is there any reason why switching to 75W-140 would not be advised versus 75W-90?

I'm not wondering if its necessary. Just if its not advisable.

75W-140 will hurt your fuel economy. At higher temps (towing heavy) the 75W-140 will offer more protection though.

rjxj wrote:
I guess we all should have stuck with that group 24 battery and 13.6 volt converter and carpet and plugging in and..........

Those are all improvements that the end user can see/feel/touch/taste the results of. Upgrading batteries on a travel trailer, you can tell because your lights are brighter and the water pump doesn't cause the propane detector to start beeping on the 3rd morning. Upgrading converters, you can again tell because your lights are brighter and you aren't replacing batteries every other year like clockwork.

A flashy bling differential cover that holds a little more fluid? Not so much.

All you have are the manufacturer's claims. You can't tell if the differential is running cooler. You can't tell if it's going to last longer. You had no idea if there was even a problem in the first place.

When is the last time you had a differential problem? The vast majority of differentials go 250,000+ miles with nothing more than an occasional fluid change. You'll get rid of the truck long before the differential goes.

The fact of the matter is that there aren't an abnormally high number of differential failures going on out there, and these covers are just "bling" products mostly designed to separate you from some of your money. Do they work as advertised? Sure, it's simple thermodynamics. Are they necessary or advantageous? Absolutely not.