Hay yall, any suggestions on what type or weight oil to use in a 1990 Manual Transmission V-6 3.9L for the Tranny and the Rear end. Doing a bit of a tune up and I do not have a manual to check. Any Suggestions would be greatly appreciated.

 

rear end - light duty use 75w-90, heavy duty use 80w-140 or whatever it is. If you're towing/hauling a lot, get the thick stuff. If it's more daily driver, get the thin stuff.

 

Thank you very much! Any suggestion on Manual Transmission Oil?? I have no clue what to get for that? Thank you very much for the assistance!

 

I've got autos in my dodges, and my chilton's is in my buddy's garage I think so I haven't got a clue. You might want to pick up a copy of the Chilton's for the 73-93 Rams or whatever the split is.

 

Here's a spec sheet from one of my service manuals. You might also consider going to synthetic.

MANUAL TRANSMISSION

Specifications
AX-15 75W-90, GL-5

A833 OD AF, AP
75W, 75W-80, 80W-90, 85W-90, 90 GL-5 may also be used

NP435 GL-5, SG, SG/CD
GL-5: Above 90°F (32°C), 140; above -10°F (-23°C), 90; below -10°F (-23°C), 80W
SG, SG/CD: Above 32°F (0°C), 50; below 32°F (0°C), 30

NP2500 10W-30,SG, SG/CD
Use AP below 32~F (0~C) to improve shift efforts.

NV4500 75W-90, Synthetic GL-4
CAPACITY, Refill:
NP435 3.3 Liters 7.0 Pints

NP2500 1.9 Liters 4.0 Pints

AX-15 3.1 Liters 6.6 Pints

NV4500 3.8 Liters 8.0 Pints

A833 OD 3.0 Liters 6.4 Pints

REAR END

Specifications
Above 90°F (32°C): 140, 80W-140, 85W-140
Above -10°F (-23°C): 90, 80W-90, 80W-140, 85W-140
Below -10°F (-23°C): 75W, 80W, 75W-90, 80W-140
Standard & all Dana, Spicer GL-5

Anti-Spin, Limited-Slip, Powr-Loc, Sure-Grip, Trac-Loc ex. Dana, Spicer GL-5*
CAPACITY, Refill:
Front: 4-wheel drive

Dakota 1.2 Liters 2.6 Pints

Spicer 60F axle 3.1 Liters 6.5 Pints

Others 2.7 Liters 5.6 Pints

Rear: 1.4 Liters 3.0 Pints

Dana 60, 60 HD 2.8 Liters 6.0 Pints

Dana 70 3.3 Liters 7.0 Pints

Others 2.1 Liters 4.5 Pints
ANTI-SPIN, LIMITED-SLIP , POWR-LOC, SURE-GRIP, TRAC-LOC IDENTIFICATION:
Lift both rear wheels off the ground, turn one wheel & other will rotate in same direction.

 

Thank you , i will print this page out! This all Helps out so much,Thanks!!!