Another rear diff oil thread, I know I know!

[capt]

2004 1500 rwd limited slip

Everyone online is saying go to synthetic but I live on an island and never drive far, never go over 60mph(no load), tow a 6-8k boat 1/2 mile to harbor 25mph max, minimal burnouts, and change diff oil about every 15k miles. Am I wrong wanting to stay with cheap Napa 80w-90 dino oil? (LS additive added of course)

thanks

 

[Snake15eyes1998]

No, you would be just fine to stay with the oil you have. But that's my opinion. Lots and lots of opinions on this forum.

 

[grpht03ram]

I think you're fine, but just FYI the service manual only recommends synthetic fluids for the rear axle. 75W140 for the smaller 9 1/4 axle and 75W90 for the larger 10 1/2 and 11 1/2 axles.

Severe duty interval is 15,000 miles. With short trips and towing you'd fall under SD

Since you change it so often I wouldn't lose sleep over it.

 

[Burla]

It really a temp thing, being in Hawaii it is likely you wont really benefit from synthetic. No cold temps where synthetics shine, and no load unless you tow heavy that makes diff get overly hot, again where synthetics shine.

 

[capt]

Thanks you guys!

 

[John Jensen]

I had a friend who lived on Maui about 3 miles from the boat ramp on the Kaanapali side of Lahaina. His truck was older and probably never saw synthetic differential oil and he never changed it that I know of. He towed his 25' cuddy cabin every week to that ramp and never had a problem. When he left us, another friend bought the truck to tow his boat as well. He too is not n oil changer and as far as I know, that truck is still in service.

I think you will be fine. Don't know what island you are on. If on Maui and if you want some synthetic I'll be on Maui in Sept, happy to bring you some

 

[capt]

Aloha John!
Thanks for the offer on bringing some synthetic. I'm on Kauai though but also think I'm going to just stick with regular oil. Hawaii has been pretty sad lately with all these lock downs and quarantine. No worky for 5 months now.

 

[John Jensen]

Kauai is so beautiful.

Sorry about no work. I have several friends in Hawaii that have not worked since the virus crap started. I just had to cancel our annual two week trip for Sept 2.