I went to the dealer this afternoon and they told me mobil 1 and Amsoil is no good to put in the differential or engine. Instead they told me the Mopar synthetic (21.00 a quart) was the only oil for the differential.

Also stated that no additive is needed in the differential contrary to what other say.

I've read a lot of post on this site and heard nothing but good things about mobil one and Amsoil.

He told me there is only one sythetic oil and it is called dynaguard4 or something like that and sais all other sythehtic oils are petroleum based and not pure synthetic.

He said if you use mobil 1 or amsoil you have to change more often to insure you don't tear anyting up.

What do you guys say about these findings? I ;ve got 55k and not changed the differential yet.

 

I would say, "dont go to the dealership"

I just changed mine to mobile 1, 8qts in my new Mag Hytec diff cover.

Changing the diff fluid is easier than changing the oil. Put it in your reclosable pan and drop it at wallyWorld the next time you go. The dealer wanted 100 smackers to do the job.

 

X2 on that... Just did mine with the mag-hytec pan.. Temps are around 110-125.



Shane

 

Correct on the no additive needed. But Mobil 1, Amsoil, RP, Rotella are fine.

 

I put RP in mine about a month ago. Easy peasy and they feel much cooler by the hand touch method.

 

ANY gear oil that meets OR exceeds the manufacturer's specifications is OK. The idiot at the dealer was just trying to push the Mopar stuff on you.

 

I've never seen anything WORSE than the oem crap! Do you tow? When does your manual say to change it? Just wondering why you waited 55k to change it. The first owner did plenty of damage to mine in only 25k! Craig

 

I used RP in mine. I don't think the original owner ever changed it. Mine had 140,000 miles on them. About 91,000 towing by the original owner and the rest by me on the highway commuting about 100 miles per day. They seem and looked fine. I'm very familiar with diffs.

 

Of course they are going to tell you that, service writers make money on the things they sell!!!!!

 

Amsoil and Royal Purple were "True" synthetics way before Mopar sold anything that was (that is if they do now). Both products have a synthetic base and not related to dino in any way. The dealer was feeding you a line to sell you over priced product. And the new diffs not only do not need the friction modifier but it seems I read somewhere on here that someone did some damage by adding it.

later,
Al

 

For the differentials you need a "GL-5 SAE 75W-90 Synthetic Limited-Slip AAM Rear Axles DO NOT REQUIRE a limited slip additive".

The quotes are from the Maintaining Your Vehicle section of the Owner's Manual. It doesn't say anything about needing to buy it from a Dodge dealership.

I bought a 5 gallon can of Valvoline GL-5 Synthetic for less than the dealer would have changed out my diffs just once. 5 gallons will give you close to 3 changes with a stock diff cover.

 

I would say you found either a complete idiot or a bold face liar!

I have been to the RP plant and I can promise you it is 100% synthetic. I run RP oils for every thing from gun oil to hydraulic fluid. The only oil i use that is not RP is my 2 stroke for my boat. (They make it as well though)

 

I have had Amsoil gear oil in the differentials since 5k miles, now around 92k. Changed fluid at 5k, 40k, and 80k. Differentials looked perfect. No problem will amsoil fluids.

 

I have seen 2 people mention the mag-hytec pan. Could someone link this to me or give me an idea where I can purchase one?

 

Seems like when I spent the 21.00 dollars per quart at the dealership it made my truck run faster !! LOL That guy is blowing smoke up your A**. Mobil 1 and amsoil are both excellent choices. He is correct in stating that some oils that are claiming to be synthetic are not really a true synthetic oil.