T-20 trans fluids... confused by all posts regarding this!

[Rusty-Gunn]

Hi. In an effort to educate myself I did about five different searches about fluids used in the T-20s. Some say to use Type F, others say add limited slip additive, and some say use synthetic. Yet some say synthetic is too slippery. Some say Type F is too grabby.
Some say change the fluids every 50 hours, others say once a year.
I'm confused. I'd like to eventually change out the fluid but I need to confirm what fluid to use.
I heard its 32 ounces. 28 if you add 4 ounces of additive. Fill to the bottom drain bolt.
What fluid is good? I'm leaning to synthetic because I heard its better for heat. But is it too slippery?
I don't get this. Help me please. Thank you.

[Normable1973]

I use type f with the additive and it works great.. Others may use different just my opinion. Norm

[msafi65]

Yours has type F with additive. I changed it when Eric owned it. I've had several vehicles that owners that work up north just think they need synthetic fluid. The royal purple stuff is very popular on the slope. It made every T20 I've ever heard noisy when installed, even with additive. The factory recommends 50 HR fluid changes.

[Tomo]

hi
Type f will give positive engagement compared to GM Dexron 3 this more so applies to hydraulic auto transmission but all the same and no matter which way u look at it f type is better for the 6x6 application.
Some 6x6 makers do state that the f type will give a better response in heavier 6x6 but my experience is that the difference is minimal
Band adjustment on a T20 Must be maintained
Band chatter is the noise u get without the additive .It is bands struggling to get CONSISTANT grip .
This happens a lot in posi [LSD] differentials .Typically experienced as diff hopping . Customers complain about the noise .
Using synthetic depends if it will mix with the additive properly ,should not be an issue but I would check with the maker .
Synthetic oil only tolerates heat better and therefore helps it last longer . Changing oil every 100 hrs cancels the benefits out.

tomo

[thebuggyman1]

I'm using synthetic in everything I own and one has a 40 horse in it. Too slippery? You would think it would show up in a 40hp/60 torque application, but it hasn't.
As far as noise......I can't hear anything over the motor.

[Rusty-Gunn]

Yours has type F with additive. I changed it when Eric owned it. I've had several vehicles that owners that work up north just think they need synthetic fluid. The royal purple stuff is very popular on the slope. It made every T20 I've ever heard noisy when installed, even with additive. The factory recommends 50 HR fluid changes.

Thank you. I was hoping you'd respond. You seem to know about Eric's machines, and yes I did buy his Msx IV which you already knew it sounds.
Type F it is.
Now, can you recommend a brand name additive? I ask for specifics simply because I know nothing about it. What is the name on the container? Thanks. I do appreciate it.

[Rusty-Gunn]

I checked our local auto store and they don't have Type F. They do have Type FA. They also have NAPA ATFfor Dextron III purposes. They have a few more but I forget what. I didn't see any additive stuff yet but didn't ask about it while there.
Would Type FA work? Dextron III suitable? Thank you.