Engine/Transmission (1994 - 1998) What weight Fluid for 96 Dana 70 Differential?

[roperteacher]

I am in the process of servicing my moms 96 CTD 5 speed with Dana 70 rear differential. What weight fluid does it take? Owners manual says 4 qts but I need to know what weight of fluid to put in it. Checked the fluid in it now and it is very brown in color and pretty heavy weight oil. Probably is a dyno oil of some type?? 80/90? How many bottles of the Friction Modifier do I need to add? Truck has 103,000 and runs beautifully!! Sorry for the dumb question, I have owned all 3rd gens. Oo.

 

[JJW_ND]

Any good GL5 Synthetic 75W90

The fluid from the factory back then was straight dino. Back then I called DANA to get some advice. They found the 75W90s provided the best protections and service UNLESS one is pulling heavy in very warm temps yearround. Then a 80W140 would be better. They caution the use of the heavier fluid (even synthetic) in cooler climates.



From what I have read, most large trucks use 75W90.



I have used Amsoil with 50K changes. I think any GL5 75W90 Synthetic would work fine. If you have a 96 5sp the rear diff is a Dana 80 which will hold more fluid. I would have closer to 5 quarts. If it is a limited slip you MAY need antislip additive. The small bottles from Dodge are the best.



No gasktet is used, pull cover, drain, whipe out old fluid, scrape old gasket material (a wire wheel on the electric grinder works wonders). Clean up with brake cleaner. I have used orange, blue, gray and black silicone sealent. All work fine. I wait about one hour and then add oil. I over fill slightly.



jjw

ND