I am asking because I want it to shift like butter (second is starting to get hard to shift into). Has anyone done this before? And if so is there any side affects?

 

Nope. It's too viscous. Manual trannies need thicker fluid, while, b/c off all the little valves and runners in a auto tranny, it needs more thin fluid, it would be too thin for a 5-speed. Run either Royal Purple 85W or Redline MT-90 synthetic. I run the Royal Purple and I love it!!

 

ok. damn it would have been so smooth. The reason I ask is because I know they do it in Mustangs and get away with it I just wasn't sure if the heat would be a factor in a RX

 

I'm sure it would. Those old brass synchros need a good thick lubricant to work well. LIke I said, I use Royal Purple 85W, and it feels like a new tranny.

 

Yes.
When I got my 88NA, the shop that did the last fluid change on the tranny (full receipts and the previous owner is my girlfriends Father) put ATF in the stick transmission. Working at an oil change, I made the swap to dyno GL5.
I then noticed grinding during quick 1-2 shifts during cold weather (140 miles on stock tranny, synchros going).
Within 100 miles, I changed the Tranny fluid again and added GL5. Still grinded.
300 miles later, I swapped to Synthetic GL5. Still grinded.
50 miles later, I changed to Redline synthetic Gl5. No change.
Eventually, I just put Dexron III ATF back in there, and the grinding went away.

I see no problems with it. I'd change it a little more frequently than normal.

Sean Cathcart
My TII is fine with Redline though.

 

I will try the royal purple if that doesn't help then I will try the ATF thanks for your input guys

 

redline all the way

 

I think they call it ATF - Automaitic Transmission Fluid- for a reason. I would never put that in my transmission.

If it is grinding that bad or dosen't shift properly it probably needs to be overhauled. If you use it and it works for you the more power to ya but I would not reccomend it.

 

i use atf in my manual. it's fine. nice and smooth

 

atf is a bad idea. i have seen a fc with it and the syncros woulnd't engage without forcing it

 

Which is why they run it stock on Mustangs, and our cars run Type F Automatic Tranny Fluid in the power steering pump.
For being just for Automatic trannies, it sure has a lot more uses .
Sean Cathcart

 

Hey lets put ATF everywhere!!! even in the brakes mabybe....sheesh You can buy Power steering Fluid. I do agree that ATF works in the Power Steering though.

I know the garages that I have worked in if the owner seen you putting ATF in a Manual transmission you would be out the door real fast and the customers rebuild would probably bee on you.

 

rebuild? hardly.
I've personally tried running ATF in my tranny, with only positive results.
Ford transmissions run ATF in them STOCK.
It may not be the best fluid to use in every application, but for some, it is.
It is fine to run ATF in a stick tranny. Those who say you can't haven't tried it.
Sean

 

Just did a tranny fluid change-out on Wednesday. The old fluid was in great shape. No stinky. But she was grinding going into 2nd at high revs. I put in Redline MT-90 on everyone's recommendations. Smoothing shifting all around and no more grinding. Me happy camper now.

I'd recommend the Redline stuff.

 

I've tried Redline, and frankly it doesn't really "work like magic" like everybody else claimed it would...

 

Ford uses composite syncros with ATF by design. IMO it's to sell you a new box every 100k. Most everyone else uses brass syncros with gear lube. Yes, synthetic is not really magic, but is works better tan anything else..

 

It isn't grinding just hard to get to second when I am gettign into it.

And I know they call it ATF for a reason but hell people are putting it in there gas tanks. Just thought I would ask.

 

I am by no means saying a person should switch from gear oil to ATF. I run synthetic gear oil. However, the original question asked if it is possible. And in my experience, it is possible.
Sean Cathcart

 

Yeah it's possible, and the syncros may bite better, but gearbox wear will be higher.

 

Hey I went out and did some research on this topic and found out lots of things. Chrylser and Ford both have 5 speed missions that use ATF in them. Most new Borg Warner manual gearboxes also use ATF now. After some long converstations ans looking through several books last night I feel tempted to try some in my transmission.

It seems I got schooled on how transmissions works and what the requirements are last night so I would like to withdraw my previouos statements.