drive fluids

1982 CHEVROLET TRUCK

99,000 MILES • 5.0L • V8 • 4WD • MANUAL

NOTAPROMIKE

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It has been years since I checked the fluids in my old pickup truck as I only drive it a thousand miles a year or less. I need to add some fluids to the transfer case and both front and rear differentials. Can I use the same 80/90 weight gear lube in all three? Do I fill it until it runs out of the fill hole? How about the transmission? That is low also. What do I use and how much? Fill it to the top until it runs out the fill hole? It is a four speed manual transmission. Thanks for your help.

Jun 6, 2016 at 7:09 AM

HMAC300

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48,601 POSTS

80/90 for differentials and transmission we have no information on it any longer. They can take 80/90 and or regular automatic transmission fluid. There are two different four speeds. check online for type of transmission. it is either a Saginaw or Muncie a Muncie will have a very low gear ratio normally in 20/30 series HD trucks.

Jun 6, 2016 at 7:29 AM

NOTAPROMIKE

MEMBER
66 POSTS

Thanks. As I understood you put 80/90 gear lube in both differentials and the transmission. How about the transfer case? A friend told me to put in either transmission fluid or synthetic 10/30 motor oil. Sound right? I have the super low granny gear in the transmission so I think it is a Muncie.

Jun 6, 2016 at 1:43 PM

NOTAPROMIKE

MEMBER
66 POSTS

Thanks. as I understood you put 80/90 gear lube in both differentials and the transmission.....How about the transfer case? A friend told me to put in either transmission fluid or synthetic 10/30 motor oil. Sound right? I have the super low granny gear in the tranny so I think it is a Muncie.

Jun 6, 2016 at 1:43 PM

HMAC300

CERTIFIED EXPERT
48,601 POSTS

the tcase maybe different altogether if you put synthetic oil in that and it has clutches they will no longer work due to synthetic being so slippery . put automatic transmission fluid in that.

Jun 6, 2016 at 3:18 PM