Mercon V in an older Ford manual

[dsmith41]

I just picked up a 95 Ranger with 40k on the odometer. Having just taken possessionof the truck, I just have to change out all the fluids. The owners manual calls for Mercon ATF in the manual transmission but I have a couple quarts of Mercon V sitting in the garage that I would like to use instead of buying more of the older stuff.

Can I use Mercon V for this application? I think I can because the Mercon V is a newer spec but I want to make sure. My understanding is you can use Mercon V for a Mercon application but you cannot use Mercon for a Mercon V application. Correct?

 

[Bluestream]

You can use it, but Redline MTL is way better for that tranny

 

[Johnny]

You can use it.

 

[Steve S]

Originally Posted By: Bluestream
You can use it, but Redline MTL is way better for that tranny
Exactly why is it better?

 

[exranger06]

Some Ranger owners have experienced rough shifting with Mercon V in the older transmissions. YMMV.

 

[brianl703]

I've been using Mercon V in the T5 in my Mustang for years...

 

[Maritime Storm]

On a 95 you're better to stick with a synthetic Mercon fluid rather than using Mercon V. As was mentioned, Mercon V has been noted to cause stickier shifting on the older M5OD transmissions.

 

[mechtech2]

Yes, you can use the new stuff.

But get some MTL or Amsoil MTF [lighter dedicated manual trans lubes] in there instead.

Why? ATF has no AW or EP additives,and is friction modified the WRONG way for synchros. Also, the real trans lubes are thicker and better for gears and bearings.

ATF is just OK. It is used because it is cheap , used in PS , auto and manual trans in the shop, and shifts easy when really cold out.
It is NOT the best choice.

 

[Bluestream]

Originally Posted By: mechtech2
Yes, you can use the new stuff.

But get some MTL or Amsoil MTF [lighter dedicated manual trans lubes] in there instead.

Why? ATF has no AW or EP additives,and is friction modified the WRONG way for synchros. Also, the real trans lubes are thicker and better for gears and bearings.

ATF is just OK. It is used because it is cheap , used in PS , auto and manual trans in the shop, and shifts easy when really cold out.
It is NOT the best choice.


This is correct.

I found out the hard way when towing my boat with my 91 Explorer 5 speed. The watery ATF couldn't take the strain/heat, and took out my bearings and main shaft. That experience lead me to find this site in 2003, and that is the first time I had ever heard of Redline MTL. Up to that point I thought the manufacturer knew what was best for their vehicles.

 

[salv]

Ford has done away with recommendations for ATF since Mercon was discontinued in favor of a reformulated Mercon V. A lot of Ford manual transmissions are now back spec'd for Ford Full Synthetic Manual Transmission Fluid. It is a 75w90 oil that more resembles motor oil than gear oil. It is suitable in GL-4 applications. Do not use a GL-5 gear oil. Your synchros will hate you for it.

I just changed my 02 Focus 5 speed MTX-75 over to BG Synchroshift II. It is awesome stuff. Anything from BG is good as gold!