1979 F150 4x4 Diffential and T-Case Fluid

Reply Subscribe

Thread Tools

Search this Thread

Feb 11, 2015 | 08:28 AM

jonmammenga

Thread Starter

Cross-Country

Joined: Aug 2014

Posts: 85

Likes: 0

From: Sioux Falls, SD

1979 F150 4x4 Diffential and T-Case Fluid

Hey Everyone,
Looking for recommedations for what to run for fluid in my front/rear differentials as well as my transfer case. My truck is a 1979 F150 4x4 with automatic tranny. The axle is a Dana 44 and the rear is a 9 inch while the T-case is a NP205. I was told I can run 80W-90 in all three of them to keep the fluid the same. Is this correct or should I run something different?

Also, I just had the auto C6 tranny rebuilt. Any recommendations for ATF for this? I also want to put a transmission temp gauge in but not sure where the best location is. I have heard the test port and also inline in the tranny exit line going to cooler.

Any feedback is appreciated!

Feb 11, 2015 | 06:52 PM

jereli

Senior User

Joined: Jan 2011

Posts: 198

Likes: 0

From: Los Angeles - South Bay

Wow you just posted just about every question I was going to post. I have same setup but its a 78. Will follow along.

Feb 11, 2015 | 06:55 PM

longview1

Banned

Joined: Jan 2003

Posts: 1,457

Likes: 0

From: Grande Prairie, AB

Lol, Im going to put 80w-90 in everything, rear/front/np435/dana21. I got a big bucket of it from work...
Not sure on what to put in the c6 tho..

Feb 11, 2015 | 07:49 PM

fuzzybob

Senior User

Joined: Sep 2013

Posts: 329

Likes: 4

From: Deer park, Wa.

66 to 76 type F.... dextron / mercon after that. Look on the dip stick it may tell you. If your older C6 has been rebuilt with newer type parts the newer fluids would be OK. You may do a search on this forum or the tranny forum for more info.