Which rear end oil?

[Sixpac2]

I am going to change the rear end oil on a 04. 5 3500 dually 3:73. I do tow a 12K fiver half time.

Which oil are people using? Mopar, Amsoil, Mobil 1, or any other to consider.

The Mopar is $19 qt, while others are $9-$10. Money is not a factor just want the best. and if there is no differance than great. Just want other opinions. Thanks for your time.

 

[DPKetchum]

I've got my Amsoil Series 2000 80w90 sitting in the storage building waiting for another few thousand miles. Just changed over our Mercury Marquis(4. 6 rwd)to it.

 

[Bertram65]

I ran Amsoil for the first 12K and then switched to Mobil 1, I could not get the Amsoil from the local supplier, he only has it from time to time so I went with Mobil 1. Seems fine, it meets the spec that is really all that matters. I would stick with 75/90 as reconmended.

 

[BIG HAULERS]

I would also like to know what the majority uses I going to have to this soon myself

 

[RWarr]

Just did my first service on the rear diff. I used Mobile 1 in the new Mag Hytech cover and all seems good so far.

 

[RGardner]

I have a 5 gallon bucket of 75-90 penzoil synthetic lube. Does anyone know about the quality of this stuff?

 

[DPKetchum]

Call them!

 

[ttreibel]

I use Royal Purple 85w-140w in the rear and Royal Purple 75w-90w in the front. The cost was about 9 bucks a quart however I had to go to the local NAPA area distribution center in Kent, WA to get enough to do the job. The Mag-HYTEC adds quite a bit more fluid.



BTW local dealer wants almost 30 bucks for there GL-5 rated gear oil :--)

 

[DPKetchum]

Who's gear oil is D. C. using?

 

[Bertram65]

Why use a weight other than the reconmended 75/90 GL5?

 

[DF5152]

doesnt the owners manual say to use a heavier oil if you tow alot?

 

[DPKetchum]

I may be wrong but I think that was discussed a lot. it seems the DANAs called for a heavy oil if towing but the AAM axels only call for 80w90. Seems some DEALERS are saying use the 80w140 but it was discussed that they were WRONG. I think someone contacted AAM and was told only 80w90. But its a only I THINK.

 

[Bill Weber]

I am going to change the rear end oil on a 04. 5 3500 dually 3:73. I do tow a 12K fiver half time.

Which oil are people using? Mopar, Amsoil, Mobil 1, or any other to consider.

The Mopar is $19 qt, while others are $9-$10. Money is not a factor just want the best. and if there is no differance than great. Just want other opinions. Thanks for your time.

I changed fluid at 15k on my 04 3/4 ton. Used Amsoil 2000 75-90. Installed a Mag Hytec cover. All is well 2k later. Tow a cattle and boat trailer in south Texas. Will check the dip stick this weekend for metal.

 

[Tony T.]

Gear Oil

I changed mine at 15K mile mark, oil that was factory filled looked good an clean. I replaced with the Castrol Syntec 75w-90 (full synthetic gear oil), it has the GL-5 rating as stated in the 03 owners manual, to use Mopar or the (equvilant) which I'm taking as having the GL-5 stamp of approval. Have now over 20K miles an no problems. Even if you don't tow I would change it out every so often for the sake of condensation purpose. It was around $7. 50 a quart. As long as it has the GL-5 rating any of the aftermarket gear oils should be ok to me (full synthetic).

 

[Rosco]

I switched the rear axle to Amsoil Series 2000 75w90 at roughly 2000 miles. Also, the truck should be around 15,000 miles by the end of summer and both the front and rear will get fresh Amsoil.

 

[ttreibel]

AA states 85w-140w is recomended for towing apps put what you want in yours but I plan on having this rear end for 250K not just the 70K powertrain warranty that Dodge is woried about. Dodge also under fills there axels and many seem to already payed the price. The fill hole is common engineering for the optimum level height of axel and transmission fluid heights.



I am using ther heavier oil to prevent foaming in high heat situations after 100K I will let you in on the results... ... 30K and no noise

 

[DPKetchum]

My neighbor has a 2003 3. 73 4x4 6 speed s. b. he tows a three horse gooseneck 95% of the time loaded. just turned 135k. He changed both diffs,transfer case and trans fliud for the FIRST time at 90k and change. All fliuds look good then. He asked me if he wasted his money doing it then cause the fliuds looked so good. :--)

 

[Elite1]

I'm running Mobile1, with the Maghytech, and I monitor the temps... seems like a good combo.

 

[t6_man]

I emailed AA and asked. They told me 75W90 synthetic for ALL applications...



I use Mobil1.

 

[RankRam]

I emailed AA and asked. They told me 75W90 synthetic for ALL applications...



I use Mobil1.

Same here!