Recommended - Transfer Case Fluid Change to 5W-30 synthetic motor

[RedBowTies88]

gotcha well if thats all it should not be too hard

[mijdirtyjeep]

I have the 3qts of 5w30 in mine as well. I removed the speed sensor with an adjustable wrench, and it was not that tight. Just lightly break it loose and then turn it out with your hand. Mine was in there I assume for around 180k and it came out just fine.

[Nuclearzero1]

Originally Posted by RedBowTies88

bringing this back up with a new question...though probably a dumb one i plan on using ATF for the case and not motor or gear oil. any reason why i should dex III or dex VI over one another? i dunno if the VI is thinner or anything....

Dex VI is fine to use as well it is replacing or probably going to replace Dex III so same properties but just recomended for newer vehicles. But I do agree with the guys as well with Using motor oil or even a higher gear weight. Its almost down to personal preference i think.. but what do i know

[GMC4Me]

Excellent find 56Nomad. Thank you for posting the link. I would hazard a “guess” that the reason for the 5w30 recommendation from the author (vs. a 90wX) might have something to do with the capabilities of this specific transfer case’s oil pump. I use 4WDH a lot and I seem to lose about a ½ pint of ATF in 10K miles so I will try 5w30 at the next service interval.

Even though I am sure it hurts my mileage a bit, I changed out both differentials to Amsoil Severe Gear 75w-110 (instead of 75w-90) at 4K miles and so far the lube looks as clean as new. The rear differential’s stock stuff was already really nasty at 4K miles, probably from break-in heat.

[mysupersportss]

So how come 3qts motor oil and not 2?

[CHYKYNLIPS]

One thing that came to mind when capacity was discussed is how is the fluid transfered in the transfer case? I know its apples and oranges, but for example, in an older lawnmower engine, there is no oil pump but a slinger type system and if the oil level is over filled, the oil cant be slung around in the engine if that part is over submersed. Does this apply at all to our transfer case?

[sparky660]

Originally Posted by CHYKYNLIPS

One thing that came to mind when capacity was discussed is how is the fluid transfered in the transfer case? I know its apples and oranges, but for example, in an older lawnmower engine, there is no oil pump but a slinger type system and if the oil level is over filled, the oil cant be slung around in the engine if that part is over submersed. Does this apply at all to our transfer case?

THat is a good question. Does the transfer case have an oil pump or does it rely on the gears to sling it and carry it.


I am sitting on the fence with this 5W30 stuff as I live in Canada where the winters get really cold. I think I will air on the side of caution and go with the less viscous fluid Syntetic ATF)for cold weather flowability. My transfer case is super quiet with 170,000 kms so if it isn't broke don't fix it.

Are there any Canadian people reading this using 5W30???

[Redram99]

I'm from Canada.

I put 5-30 syn in my transfer case. But will only be using it for the summers and will change back to ATF for the winter. -40 does is hard on things so I think I would be better off with ATF in the winter.

The syn motor oil allows my tcase to shift easier and operate quieter.

[Hondarider552]

Originally Posted by mysupersportss

So how come 3qts motor oil and not 2?

more is better in terms of the life of the tcase

[mysupersportss]

Originally Posted by Hondarider552

more is better in terms of the life of the tcase

So if I decide to do atf should I do 3qts or just to spec and do the 2qts?