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Royal Purple Synchromax Manual Transmission Fluid

100+ Reviews
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  • Item #45004
  • MPN# 1512

  • Market Price $25.99
  • You Save 12% ($3.00)
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  • Smoother Shifts
  • Better Transmission Performance
  • Superior Protection
  • Full Synthetic
  • Resists Breakdown
  • 1-Quart Bottle
Protection. Royal Purple Synchromax® is a full synthetic transmission fluid that provides superior wear protection for your Mustang's drivetrain. Synchromax® is formulated with Royal Purple's synthetic, proprietary Synerlec® additive technology, which offers improved shift quality over a wide temperature range and reduced gear noise. Use Royal Purple Synchromax on your Mustang's next fluid change for the cheapest insurance you can get against future transmission breakdowns.

Better Shifts. If your transmission is notchy, rough, or loud but is mechanically fine, a fresh fill of Synchromax® can help smooth things back out. If you have a new Mustang or transmission, changing your fluid to Synchromax can keep your transmission working better - both now and later.

Protects Internal Components. Synchromax® is fully compatible with all types of friction materials and offers excellent corrosion and oxidation protection without affecting the soft metals commonly found in manual transmission synchronizers.

Application. Synchromax® is recommended for manual transmissions that specify an automatic transmission fluid or motor oil. Please note the T-45/T-3650 will take approximately 3.25 quarts to fill the transmission after a full transmission fluid flush.

Fitment: 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 Details

What's in the Box
  • (1) One Quart bottle
Installation Info
Will it fit my Mustang?
  • Boss 302 - 12, 13
  • Foxbody - 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93
  • Mach 1 - 03, 04
  • V6 - 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15, 16, 17
  • Bullitt - 01, 08, 09
  • Cobra - 94, 95, 96, 97, 98, 99, 01, 03, 04, 93
  • GT - 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15, 16, 17
  • GT500 - 07, 08, 09, 10, 11, 12, 13, 14
  • EcoBoost - 15, 16, 17

Fits manual transmissions

Most Helpful Reviews

Royal Purple Synchromax

I recommend using this transmission oil in your t-56. American muscle is where to buy this product.

Helpful (2)

much better shiffiting now

Shifts a lot more smooth now. Even seems to have reduced the minor vibration problems i had at high r.p.m.'s. Filled it through the top from shifter while leaving the fill plug open and it made life so ...

Read More
Helpful (2)

Overall Rating 4.8 out of 5 stars
Read All 100+ Reviews

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16 Questions / 17 Answers

Ask a Question

how many would i need for my 03 roush stage 2?


  • If your stage 2 is a manual then you have a TR3650 and you need to buy 4 bottles. You will actually use 3.2 quarts or so if its done right.


    Good Answer (0) (0)

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Safe for TR3650 Some guys on the mustang forums suggest this stuff eats away at the internals of the TR3650 in the 05-09's. Is it a safe buy or a no-go?


  • I've run this in my 2004 3650 for well over 50K miles. I've had zero issues (other than normal age and wear) to date and my transmission has 102K on it right now with no rebuild and only one clutch change.


    Good Answer (1) (0)

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  • The T56 service manual recommends Dexron lll fluid. You can use Royal Purple syncromax or GM syncromesh type fluid also.


    Good Answer (0) (0)

Show 1 more answer Question Resolved

Do you have to have a new transmission or stang to swith to the royal purple? I would like to swith the transmission fluid in my 2002 mustang. My tranny shifts hard and would like to try new fluid.


  • No, you can use Royal Purple without issue. I run it in my 3650 and have for years. Make sure you get the right fluid for your type of transmission and the right amount. IF you don't have a manual, buy a Haynes or Chiltons to determine capacity.


    Good Answer (0) (0)

Show 4 more answers Question Resolved

Can I just take off the shifter to refill the transmission fluid instead of using the fill plug?


  • Absolutely, it's way easier then trying to do it from under the car. What I usually do is start off by being on a level surface, pull the fill plug, slide a catch pan under the car and fill the trans until it just starts to drain out the fill hole. This way you know you've got it topped off but not overfull.


    Good Answer (0) (1)

Show 3 more answers Question Resolved

2011 Auto Trans.? Would this be good for my 2011 5.0 if it is Automatic? I noticed it said 'for manuals' in the explanation. plz help! want my baby to run smooth.


  • I would not put that in an automatic transmission. I have it in my 94 T-5 manual transmission, and it works great. Royal Purple makes a great automatic transmission fluid that will work perfect for your car.


    Good Answer (0) (0)

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Customer Reviews (100+) Write a Review

Overall Rating 4.8

out of 5 stars

  • 5/5

    August 21, 2016

    MT-82 became butter

    I did a lot of research on what fluid to use in my 2012 GT/CS. I looked at many reviews for Redline products, Lucas, and Royal purple and by far the Royal Purple had the MOST reviews and the most positive. I could not find a truly negative review. So I took a leap and bought it. After changing from my stock fluid, which came out looking like dirty motor oil, I let the car get to operating temperature and then gingerly drove around the block a few times to let the transmission as well before I got on it hard. I could definitely tell a difference right away. The shifts felt less notch, mind you I have a Barton shifter with two post bracket, and easier to engage. All in all I think it was worth the little bit of extra money to go with the Royal Purple.


    Year: 2012 Submodel: GT

    Helpful (1) (0)

  • 5/5

    February 17, 2013


    Great product. Smooth shifts. Would highly recommend this product.


    Year: 2002 Submodel: GT McKinney, Texas

    Helpful (2) (0)

  • 5/5

    November 29, 2012


    Did no think i was going to get results like i did. I had my doubts but changed my mind as soon as I started driving. Smoother shifts than Micron. I will be switching to ro yal purple from now on. Well worth the money.


    Year: 2010 Submodel: GT Spring, TX, USA

    Helpful (2) (0)

  • 5/5

    October 03, 2012

    notchy trans

    08 Bullitt trans always hard to shift, 2nd up or down very had to get, first would buck on low speed coast. put Royal Purple in and immediately could tell a difference, smooth shifting, coast smoothed out. 2nd gear is great up or down now.


    Year: 2008 Submodel: Bullitt Nashville, TN, USA

    Helpful (1) (0)

  • 5/5

    September 28, 2012

    stopped car from grinding!!

    car started to pop out of gear and did alot of grinding i have benn running this for a couple of months now problem solved switching all fluids to royal purple now!


    Year: 2004 Submodel: GT Clinton ct

    Helpful (2) (0)

  • 5/5

    September 04, 2012


    Royal purple synchromax Makes your pony go faster, better acceleration and smoother shifts. I used this on my 2001 GT and now im using it on my 2003 GT and works awsome. Royal purple is the best oil for your Mustang NEEDS.


    Year: 2003 Submodel: GT Midland, TX, USA

    Helpful (1) (0)

  • 4/5

    August 20, 2012

    Smooth shifting

    Great substitute for The worn Out factory ATF. Smother shifts


    Year: 2004 Submodel: GT Indiana, USA

    Helpful (1) (0)

  • 5/5

    September 24, 2011

    keeps the tranny cooler

    I installed the royal purple when i put a new steda shifter , clucth cable kit with new quadrant and fire wall adjuster. The shifting is awesome now and because of the royal purple i can tell my trans is staying cooler. I also had a little sycro noise in 3rd and 4th , but after several weeks use its gone away. though i did need 4 quarts and ordered them accordingly after reading the other reviews. thanks american muscle


    Year: 1989 Submodel: Other michigan

    Helpful (2) (0)

  • 5/5

    September 20, 2011

    much better shiffiting now

    Shifts a lot more smooth now. Even seems to have reduced the minor vibration problems i had at high r.p.m.'s. Filled it through the top from shifter while leaving the fill plug open and it made life so much more easy on me. Put the shifter back on with the Shifter Base & Handle Gasket that here has and lo and behold, no leaks. The only mistake I made was I forgot the T5's take about a Qt. less than the T45's, so now I have an extra Qt. sitting in the tool box. Remember people, do it your self means DO YOUR RESEARCH before you even think about buying the parts you need/want. Would recommend this to anyone.


    Year: 1999 Submodel: V6 El Monte, CA

    Helpful (2) (0)

  • 5/5

    February 16, 2011

    Royal Purple Synchromax

    I recommend using this transmission oil in your t-56. American muscle is where to buy this product.


    Helpful (2) (0)

  • 5/5

    September 03, 2010

    Royal Purple Synchromax

    After I installed a short throw shifter, I could hear gear noise in the transmission. This produce significantly reduced the noise! I am very happy with it.


    Helpful (1) (0)

  • 5/5

    June 04, 2010

    96 cobra

    rp really makes for some great shifts, really can feel the diff. will use again.


    Year: 1996

    Helpful (1) (0)

  • 5/5

    February 12, 2008

    RP Syncromax

    I love all of RP stuff , it\\\'s the only fluid I put in my car and the Syncromax lives up to the reputation of RP. The T-45 in my car shifts better and runs a lot smoother. Also AM is the best web site for all your Mustang needs.

    Audie Lockhart

    Helpful (2) (0)

  • 5/5

    June 08, 2010

    oyal Purple Synchromax

    well i totally noticed the smooth shifting thats what i enjoyed the most great stuff.


    Helpful (5) (2)

  • 5/5

    March 08, 2010

    Good stuff

    Awesome product, shifts a lot smoother. Pair this up with the applicable gasket to your transmission and you have the perfect excuse to hide in the garage from the wife and improve the drivability of your Stang.

    Oh For Pony

    Helpful (26) (5)

  • 5/5

    August 08, 2011

    Shifts like hot butter

    I put some of this in at 70k it was definitely an improvement but it was also the first transmission fluid change. The improvement was noticeable but I can't say that it was from the royal purple and not from it just being fresh tranny fluid. I have a hurst shifter and with this fluid you can feel every single movement in the shift. I love it that way. I feel more connected like I know how the car is behaving. I would recommend this to anyone else.


    Year: 2006 Submodel: GT

    Helpful (6) (0)

  • 5/5

    June 25, 2010


    before my shifter got scorching hot and shifting through gears required a little effort when tranny got warmed up, with synchromax paired up with the short shifter gasket set eliminated my hot shifter and now my tranny shifts smoothly i would deffinately reccomend this product to anyone

    Kolby Riley

    Helpful (9) (2)

  • 5/5

    November 14, 2009

    Royal Purple Synchromax

    I have a 03 Mach 1 with a T-3650 and Ford sez 3.8 quarts of fluid, I put in 3.25 quarts and it was not full so I put all 4 quarts in and its just up to the fill hole. The Tranny shift real smoth now, great improvement from the stock fulid.

    Doug Russell

    Year: 2003

    Helpful (10) (3)

  • 5/5

    January 28, 2012

    Smooth Operation

    I have the new China made 6speed in my 2011 mustang and I tell you what it was very stiff going into gears cold and hot. This product helped out a lot. I would recommend this to anyone wanting to smooth out there transmission and also add better protection.


    Year: 2011 Submodel: GT Fuquay Varina, NC

    Helpful (5) (0)

  • 5/5

    November 29, 2012

    TR3650 Second Gear Hitch

    I have a 08 GT, with pretty much every bolt on there is, bought it new, and it has always had a hitch (a little difficult) going into second. Just changed to RP Synchromax, and what a difference, this oil really made a difference. Hitch completely gone, yes, gone, and all other gears are smooth as silk. I have to tell you, if you haven't changed you Tranny oil, you are really missing out on a quality upgrade. Banging second gear with confidence now, and yes, it has had the Tri-Ax since almost new. Worth every penny boys and girls.


    Year: 2008 Submodel: GT Jacksonville, FL, USA

    Helpful (3) (0)