Piston Slap: The ZX2 Needs Some Honey

Sajeev Mehta
by Sajeev Mehta

TTAC Commentator Shane Rimmer writes:

I have a 2002 Ford ZX2 5-speed with about 80,000 miles on the odometer. For peace of mind, I plan to change the transmission fluid soon. The book calls for Mercon automatic transmission fluid, but I have read that synchromesh is the better choice. I’d like to get the thoughts of the best and brightest on which I should use or if I should just leave it as is since there are no problems.

Sajeev Answers:

If this car is a keeper, changing the fluid is an excellent idea. And why wouldn’t it be? One of the final tributes to Ford’s design leadership (before the J Mays era of VW-wannabes) certainly deserves a revitalized gearbox. But what fluid: the factory stuff, synchromesh, or a full synthetic?

Keep in mind the factory ATF is a semi-synthetic (Mercon V) which is a good start. But most who switch to synchromesh notice smoother gear changes. I certainly did. Synchromesh isn’t the be all/end all to upgrades, but a quick search of forums show that many Sport Compact owners find the conversion worth it. Not to mention this stuff is plentiful and cheap. Dirt cheap.

Upgrading to a full synthetic is another valid option. Since the ZX2 is an Escort, Ford has a synthetic fluid that’s a safe bet for durability and performance, and (again) the forums agree. The stuff is nicknamed “Ford Honey” because of the color, but it’s simply synthetic transmission fluid sold in a Motorcraft bottle.

Your call. And your preference. I’d recommend a relatively wallet-friendly switch to synchromesh and try it out for a while. But, again, there’s no wrong answer. Off to you, Best and Brightest.

(Send your queries to mehta@ttac.com)

Sajeev Mehta
Sajeev Mehta

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  • Bnolt Bnolt on Apr 08, 2010

    I changed the fluid in my 99 SVT Contour to the 'honey' a couple of weeks ago. Shift feel is better than new at 96,000 mi. The factory fill was ATF, and I did 2 previous changes with Mobil-1 ATF & a couple of ounces friction modifier. This 'cocktail' was supposed to be the hot ticket back in the day. This is a good example of not always trusting the owners manual. Ford did change their fluid recommendation on the MTX-75 in the year 2000 or so. There's some evidence that ATF gums up the works a bit, and the 'honey' does indeed have a lot of anti-sludge/varnish additives. As Sajeev mentions, there's a lot of good information on various forums. Try a combination of MTX-75, BITOG, Terry Haines, & XT-M5-QS. You'll learn more than you probably want to. The Ford stuff isn't cheap ($15.00/Qt), but since the tranny in the ZX2 only holds 2 quarts, it won't break the bank. On the other hand, I put 240k on my old 86 Escort GT and never changed the fluid, so maybe this is a little OCD. However, I'd recommend the change just for shift feel alone.

    • Sastexan Sastexan on Apr 09, 2010

      I'm in the same category as you with my '98.5 Contour SVT, although I made Ford switch my car under warranty around 30k to the "honey" (complain enough about stiff shifting when cold, and prove it, then show TSBs and other data covering the MTX-75, you can go a long way). I ended up rebuilding the tranny at 100k (put in a quaife and revised shift forks as long as it was apart - thanks to Terry Haines) and refilled with the "honey". Now approaching 140k, suitably still tortured often, and holding up strong.

  • Newcarscostalot Newcarscostalot on Apr 09, 2010

    I think the reason that new cars with manual transmissions require automatic transmission fluid is because the clutch is hydraulic, as opposed to mechanical. Old manual transmissions used 90 weight gear oil.

    • Porschespeed Porschespeed on Apr 09, 2010

      Hydraulic clutch is defined as a means of actuation, as opposed to a manual clutch. A 'manual clutch' is engaged/disengaged directly by a cable or a rod system. A 'hydraulic clutch' is engaged/disengaged by a master/slave cylinder arrangement. This is distinctly different from a wet-clutch scenario, that is typical on motorcycles.I'm trying to think of a car that I have wrenched that has a wet clutch and my number is still zero. Ergo, clutch fluid? That's like turn signal fluid....

  • Newcarscostalot Newcarscostalot on Apr 09, 2010

    I just realized I made a mistake! Clutch fluid and gearbox fluid are separate. Doh... So, why then do new cars/trucks use ATF and old cars/trucks use 90 weight gear oil?

    • See 9 previous
    • Porschespeed Porschespeed on Apr 09, 2010

      Very true, the VW chippers should provide some interesting field testing. My sourcing will be from some horribly stuffed Pooch from an insurance auction. I'm in no hurry to grab one, by the time I get done with the current projects, they should be a bit more plentiful.

  • Newcarscostalot Newcarscostalot on Apr 09, 2010

    Wow, thank you! I am sorry as well for reacting in a rude manner. I am an ass as well, obviously... :-D

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