What fluid is recommended for a WC T5? Would I be ok with Redline?

[TomCat]

Hey, I'm getting a new T5 installed soon, and I was wondering if it will be ok with me using Redline MT90. I've used this stuff in all my other manual cars, and it's awesome. Will it be ok in the stang? If not, what would you recommend?

Thanks!

-Brandon

 

[HISSIN50]

When I did my fluid, Redline's tech advised using D4 over MTL or Mt90, even though I live in the desert (I was going to use MTL and wanted to check if that was acceptable).

On a new trans, I would use the thin stuff (D4). Just my thoughts.

Good luck.

 

[TomCat]

Thanks... I live in a desert hot climate too. I suppose those techs know what they're talking about, so I'll got with the D4.

Thanks!

 

[HISSIN50]

Brandon, Adam (89MustangGX) has some info from a trans builder (like Hanlon IIRC) that one can use a different fluid in hot climates.
It seems to me that Adam did that and it was fine till it got colder out. But if your trans has a warranty, I would definately stick with whatever fluid it comes with (swapping to a synthetic ATF should be alright). Otherwise, I can envision warranty issues, should you need to warranty it.

I dont really see a need to use thicker stuff anyhow. The D4 seems to do fine in 115*F temps here.

Just my two cents.

 

[DW5.0L]

I would stick with ATF. Thats what most of the builders recommend, as does the manual. Gear oil can ruin your T-5. Happened to mine a long time ago when some idiot at a quick lube put some in it.

Here's a quote from fordmuscle.com: "Synthetic ATF
First of all don't use anything but ATF (Mercon-Dextron II / III) in your T5. Unlike many manual transmissions, T5's do not work with gear oil or MTF. While many people question the value of synthetics, we've found that the T5 shifts smoother and there is less grinding with synthetics. Since you are only going slightly less than three quarts, it's worth spending the $10. Plus it will last longer and won't need replacing as often as conventional ATF. We like the Aamco synthetic blend, but Mobil one full synthetic works great as well for a few extra dollars."

 

[Rick 91GT]

I found the Redline did not allow smooth engagement or engagement at all in the higher rpms when I had a t-5. A swap to regualr Mercon III took care of that issue..

Tranny was fresh...

 

[85mcLaren]

The T-5's are a hit or miss with synthetics. Sometimes, the synthetics won't allow the blocker rings to slow down the synchros quick enough for fast shifting in upper rpm's. This in turn will obvious wear them out (rings and synchro gears) even quicker. If it grinds with synthetic, I would go back to regular ATF. Had to do that on one of mine. One was fine with synthetic, the other didn't like it.... Just my .02 cents.

Jason

 

[HISSIN50]

Hmmm, I wonder what the parameters were for that article. Older stang T5's, as well as Bronco T5's, some Camaro T5's, et al, used gear oil.....

Rick, I hope ya had a great Honeymoon!

 

[darthcual]

I'm redoing my spline yoke seal this weekend and this post caught my eye. I was going to use that royal purple stuff as it seems with the regular mercon i get some grind in first and second(especially when the tranny is cold). Do I need to ask for a certain kind of number on the royal purple or will the ford racing shop know? Thanks in advance.

 

[1EVIL88VERT]

i use royal purple ATF in mine and it shifts perfectly

 

[darthcual]

i use royal purple ATF in mine and it shifts perfectly

Is it an automatic or manual?

 

[1EVIL88VERT]

T-5

 

[maverick0716]

Hmm.....that's very interesting about the use of synthetic with high rpm use. I'm having trouble shifting my car at my 5800 rpm shift light....I thought it was my clutch not being adjusted properly, but I never had a problem shifting at 5200 rpm with my stock heads/cam combo.

 

[89MustangGX]

Brandon, Adam (89MustangGX) has some info from a trans builder (like Hanlon IIRC) that one can use a different fluid in hot climates.
It seems to me that Adam did that and it was fine till it got colder out. But if your trans has a warranty, I would definately stick with whatever fluid it comes with (swapping to a synthetic ATF should be alright). Otherwise, I can envision warranty issues, should you need to warranty it.

I dont really see a need to use thicker stuff anyhow. The D4 seems to do fine in 115*F temps here.

Just my two cents.

Agreed.