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T-5 Transmission Fluid Question

  • Thread starter Thread starter Rockin302
  • Start date Start date May 22, 2005
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Rockin302

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Mar 24, 2002
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May 22, 2005
#1
  • May 22, 2005
  • #1
I've searched this forum and it seems everyone uses different fluids for their T-5's. I have a 1990 lx 5.0 with a 5-Speed ( I think that's the T-5, correct me if I'm wrong) and I'm about to change the fluid. The manual asks for mercon but people have suggested using Royal Purple Synchromax, GM Synchromesh, Redline ATF, Mobil 1 Synthetic ATF etc... So what's the best stuff to use for the smoothest shifts and best protection? Thanks!
 

stang22

Active Member
Jan 29, 2003
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Washington, D.C.
May 22, 2005
#2
  • May 22, 2005
  • #2
I think I use Dextron II. That is what was recommended to me when I changed my tranny fluid.

Tim
 

5spd GT

"the 5.0 owns all"
Founding Member
Aug 7, 2002
9,516
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Arkansas
May 22, 2005
#3
  • May 22, 2005
  • #3
You want Dexron/Mercron III ATF fluid for the T5...that is the factory fluid needed.

When you see the GM Syncromesh it is not likely for the T5 but probably the TKO tranny...

Mobil 1 makes some good fluid...and D4 is excellent stuff from what I hear
 

mustangjoe87

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Jul 23, 2004
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Harrison Twp., Michigan
May 22, 2005
#4
  • May 22, 2005
  • #4
Valvoline dextron mercron lll ATF
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
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May 22, 2005
#5
  • May 22, 2005
  • #5
As David said, D4 works well, IMHO (what I run).

good luck.
 

Stang8URMPRT

Active Member
Dec 28, 2003
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Daytona Beach, FL
May 22, 2005
#6
  • May 22, 2005
  • #6
Yep, I use Valvoline Dex III ATF. Works good.
 

Henceforward

The Avatar Master
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Jul 17, 2001
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May 22, 2005
#7
  • May 22, 2005
  • #7
When I changed my fluid last month, I used Dexron/Mercron III from Castrol...
 

QuickCapri83

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Sep 5, 2004
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North East, PA
May 22, 2005
#8
  • May 22, 2005
  • #8
A friend of mine that owns a shop in slatington PA, recommends regular atf dexron/mercon III, that's it. My buddy had 10psi s trim lots of other mods with stock t5, used reg fluid it lasted 3 yrs, beatin' the crap out of it nonstop. I, myself, run regular cheap fluid, i'm in my 4th year with my original tranny which has 146k on it. Better fluids are probably better, I guess, but I would stay away from additives.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,216
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Massachusetts
May 22, 2005
#9
  • May 22, 2005
  • #9
D3 is what you should be running.

Some guys get away with different fluid types, but the T-5 was designed for D3 ATF
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,216
17,899
224
Massachusetts
May 22, 2005
#10
  • May 22, 2005
  • #10
D3 is what you should be running.

Some guys get away with different fluid types, but the T-5 was designed for D3 ATF
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
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May 22, 2005
#11
  • May 22, 2005
  • #11
Mustang5L5 said:
D3 is what you should be running.

Some guys get away with different fluid types, but the T-5 was designed for D3 ATF
Click to expand...
Mike, you gotta watch it with the acronyms - at first blush I thought you were saying that Redline had a variant of Redline D4 that was for use in T5's. (I am being serious. for a minute, i was thinking 'Huh').
 
R

ratrapp

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Apr 24, 2004
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buena vista,va
May 22, 2005
#12
  • May 22, 2005
  • #12
i use royal purple synchromax.had good luck with it so far.
 

stang22

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Jan 29, 2003
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Washington, D.C.
May 22, 2005
#13
  • May 22, 2005
  • #13
5spd GT said:
You want Dexron/Mercron III ATF fluid for the T5...that is the factory fluid needed.
Click to expand...

My mistake in my first post. I meant to say Dexron/Mercron III, or whatever the stock fluid was.

Tim
 

txstang84

15 Year Member
May 21, 2005
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Tuscola, tx
May 22, 2005
#14
  • May 22, 2005
  • #14
i'm still runnin the D/M III...works like a champ-btw way, quickcapri83-Sharp lookin' four eye
 

89MustangGX

I have nothing productive to add!
Jul 3, 2001
10,262
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Mill Creek, WA
May 23, 2005
#15
  • May 23, 2005
  • #15
I have recently heard a couple people say that regular ATF is better than synthetic, but I have a hard time with that.

I would go for any of the good name synthetics depending on what you like and what's available -- and cost of course.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
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May 23, 2005
#16
  • May 23, 2005
  • #16
89MustangGX said:
I have recently heard a couple people say that regular ATF is better than synthetic, but I have a hard time with that.
Click to expand...
I agree with ya bud. with all the strange things people try in their WC T5's, it is hard to pick out the decent info (I am waiting for someone to try frying oil). a manual trans is not really stressing the hydraulic fluid like it would be in an automatic, so i dont think one can go too far wrong.

As you know, I am a fan of the synthetics. for the cost difference between conventional and synthetic (for 3 bottles) and how infrequent one needs to service the fluid, synthetic always gets my vote personally (matter of fact, your input last change helped me to stay with the D4 rather than try something else).
 

Bobert

New Member
May 18, 2005
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May 24, 2005
#17
  • May 24, 2005
  • #17
Has anyone actually noticed a better shifting t5 by switching fluids?
 

SNAKEYES86GT

Member
Jun 24, 2004
59
1
9
Downers Grove, IL
May 24, 2005
#18
  • May 24, 2005
  • #18
I just changed my tranny fluid an hour ago and motor oil poured out when i took out the drain plug. Now there's Dex/Merc III in there and it's like butter. Like butter I say. Now I understand what my short shifter was supposed to feel like all along. Used cars suck.
 

maverick0716

Founding Member
Jan 12, 2002
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Chilliwack, BC, Canada
May 24, 2005
#19
  • May 24, 2005
  • #19
Bobert said:
Has anyone actually noticed a better shifting t5 by switching fluids?
Click to expand...

Smoother shifting yes. Comparing Castrol ATF Mercon (III or IV) against Redline D4.
 

Bobert

New Member
May 18, 2005
63
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May 24, 2005
#20
  • May 24, 2005
  • #20
maverick0716 said:
Smoother shifting yes. Comparing Castrol ATF Mercon (III or IV) against Redline D4.
Click to expand...

Is this D4 a synthetic? Thanks.
 
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