Transfer case fluid change

[Bobweb]

I am changing the transfer case oil. I’m not sure what the previous owner used In it. I have read all the different threads on different types/weights of oil. I have straight 30w non detergent oil already in bulk. My question is, will straight 30w burn up my transfer case? I’d like to use it if it is possible and won’t do damage but don’t mind spending the money if it really is that important to get a heavier oil. Although there is so much knowledge out there, I’m still not sure what to make of all of it. Any and all comments are welcome. Thanks

p.s. I have looked at the fluids chart frank8003 posted and it seems like 30w is close to 80/90?

 

[INFChief]

I am changing the transfer case oil. I’m not sure what the previous owner used In it. I have read all the different threads on different types/weights of oil. I have straight 30w non detergent oil already in bulk. My question is, will straight 30w burn up my transfer case? I’d like to use it if it is possible and won’t do damage but don’t mind spending the money if it really is that important to get a heavier oil. Although there is so much knowledge out there, I’m still not sure what to make of all of it. Any and all comments are welcome. Thanks

p.s. I have looked at the fluids chart frank8003 posted and it seems like 30w is close to 80/90?

I would use a gear oil (GL).

 

[glcaines]

I would use a gear oil (GL).

I agree. I purchased 5 gallons of NAPA brand GL-1 SAE 90, which I've been told is the same as Valvoline brand, but a lot less expensive.

 

[Bobweb]

I agree. I purchased 5 gallons of NAPA brand GL-1 SAE 90, which I've been told is the same as Valvoline brand, but a lot less expensive.

Would this be ok for transmission also?

 

[kenn]

Hmm... I've been reading a ton of old threads on this very issue and it seems like the best advice is to use the original product in the LO 9-2320-209-12-1 . That would be, for most climates, 80/90 Gear Oil. I'm not sure on the GL1 vs GL5 specification as there is all sorts of conflicting information concerning yellow metal and sulphur. That said, MT-1 rated GL-5 is supposed to be OK. Orielly has their house brand, "Master Pro" which says GL5 and MT-1 right on the back and with a 20% off coupon is a pretty good deal. I just ordered that to do the transfers and transmission case. One lube rules them all.

 

[ToddJK]

I would stick with gear oil for the transfer case for sure. You can also use that in the transmission as well, but Spicer did spec to use 40 SAE non detergent oil. Like Kenn said, the argument on which to use in other threads can be confusing, but as long as the lubricant is stated to be yellow metal safe, that's what's important.

 

[ToddJK]

 

[rustystud]

I've written on this topic for years now. I've even called the manufactures of the gear boxes. The best oil for a transfer-case/differential that see's heavy gear load (shear) should be a gear rated 80w/90 to 90w/140 oil. Depending on the climate use the 80w/90 for colder temps, and the 90w/140 for warmer temps.

 

[Bobweb]

I really appreciate the feedback guys, I just want to make sure I get it right. Thanks again