how to change the oil in the transfer case if needed

[tiffy's W150]

Hello Guys............
thank you for helping with GOOD tips on my 1983 W150 with the 318-1. I still have alot of other questions to ask so bear with me guys. I am trying to improve the mech. condition on my truck by changing all oils of the axles, tranny, power steering and transfer case and so on as i know this will help make it to 300,000 miles. That will give me plenty of time to save up for new 318 or 360 (prefer the 360) that if someone can help me with making the 360 with the RV cam smog legal in my half ton short bed W150. The question # 1 is how to change the transfer case oil or is it sealed for the life of the unit ? The question # 2 what weight gear oil should i replace on my mopar 9 1/4 rear and dana 44 front ? i mean should i change it to heavier weight oil due to high mileage as I think my truck has least 170,000 on it before the speedo cable broke and the whole drivetrain is in GOOD condition (no sign of rough handling or heavy beating on the truck). there is VERY little rust on the whole body i guess i got lucky on this truck. sorry for long page as i want to learn everything about it and make it my everyday driver for next 30 years( not kidding) SMILE
thanks guys........
Tiffany

[USN78W150]

oils

Your transfer case should be a NP208 model. There is a drain plug on the bottom that you will remove to drain the old oil out. There is a fill plug on the rear facing side of the case. Fill it with new oil until it just starts to spill out the fill hole. Your axles will use 90W gear oil. Make sure the gear oil you purchase has additive that makes it compatible with limited slip differentials. You can buy the additive separately if needed. Your 9 1/4" rear axle may have a limited slip differential. If so, it will need a few ounces of the additive poured into it.

[tiffy's W150]

Hello USN78W150....
90 weight gear oil plus few oz. of addive for the 9 1/4 rear, just 90 weight for the dana 44 front correct? what weight oil to use on the NP208 ?
thank you for your help, i am learning SMILE.

Tiffany

[USN78W150]

oil

Tiffany,
Use Dexron III automatic transmission fluid in the transfer case. :)

[DODGEBOYS]

yup Dexron lll if you dont use it much

if you actually use 4x4 for hours on end more than 1 day a week then use straight 10w non-detergent motor oil with a bottle of Lucas standard tranny additive

my hard core rock crawling truck was eating two 208 t-cases a year use,in Dexron lll / l switched to what l said above and have had the same t-case for 8 years doin the same kind of wheeling