Can anyone recommend a good synthetic oil to go in the my 6 speed? I live in Alaska so I would like to see if I can gain some MPG here with synthetic. I would also like to find a synthetic gear oul for my axles front and rear but I hear Ford Diffs are very picky on the oil. Any comments?

 

Redline D4 ATF.

 

Kwik beat me to it.

 

I am running royal purples syncomax.

 

ATF for a standard? Wow who would have thought? Is that good for the stock limited slip diffs also?

 

Just add fords limited slip additive with the recommended weight gear oil

 

Lmao..i didnt because i didnt have any additive or the right weight. I stuck in some chevron 90W and now ive got posi....oh yay. Clutch pack was gone anyhoo...but im suprised it has been so good to me

Ford sells there additive for about $16 but not sure how much you need. Ask before going to buy...they might not have it on hand.

 

I ran regular gear oil without the additive for like 6 months, the rear end clicked when I turned. I was riding on the tailgate while someone pulled it to the front of the house and figured out what it was. Added the ford stuff and its fine now.

 

Forman I am interested to know why you and Kwik recommend Redline D4 ATF. I havnt looked at my manual for my truck yet because I am at work but I was suprised to see ATF for my trans. I don't know much about manual transmissions. Thanks for your responses.

 

I have the syncromax, I think the royal purple is 10w. Ford calls for an ATF in the ZF5, 6 tranny.

Both your trans and transfer case need ATF.

 

OOPS I see it was FordBronco69 and Kwick made that recomendation. Thanks Foreman for comming back on that. I think I am going to try to find that Redline D4 atf. I hope I can find it here in Kodiak.

 

i notice my truck shift alot smother when warm, i have never experianced a manuel that did this (never owned anything this big either) is that normal? not a big difference but after she has been on the hiway she seems to shift smother.

 

I had to order mine from summit racing because none of the napas around here carry royal purple. Not to sure who carries redline, but you can order it and have it to you in 3-4 days. I know it made a little difference for the better how mine shifts when towing.


spunks00 check your fluid, it may have a gear oil in it that is too thick for it when cold.

 

Yes that is another reason I want to switch to synthetic. My trans is a lot harder to shift when cold. I grind them sometimes when it is cold. Been like that since I first picked it up new from the lot.

 

The synthetic will help with that a lot.
Any brand will do, Mobil 1, Royal Purple, Redline, etc.