Royal Purple Synchromesh Manual Transmission Fluid - 1 Quart

Royal Purple Synchromax Manual Transmission Fluid - 1 Quart

You just bought a used Integra and the guy before you never changed the transmission fluid. Second gear grinds when it's cold, the shifter feels like it's full of gravel, and you're pretty sure there's 150,000 miles on the factory Honda MTF. Or maybe you're building a turbo Civic Si and you want transmission fluid that's not going to break down when you're making 400 whp and beating on it at the track. Royal Purple Synchromax is what you run. This isn't some mystery fluid from a parts store shelf. Royal Purple's been making synthetic lubricants since 1986 and Synchromax is their manual transmission fluid that actually works with synchronized transmissions instead of just being thick gear oil in a different bottle. We've switched dozens of Hondas and Acuras from factory MTF to Synchromax and every single person comes back and says the same thing: shifts are smoother, second gear stops grinding on cold starts, and the transmission feels ten years younger. This is a single 1-quart bottle. Part number 06512. Your transmission takes about 2 quarts so you'll need two bottles.

Here's What Happens When You Don't Change Your Transmission Fluid

Your manual transmission's got brass synchro rings inside that match the speed of the gears when you're shifting. Every time you shift, those brass rings are rubbing against steel gear cones. That creates metal particles. You've also got the gears themselves meshing together under load. More metal particles. All of that metal ends up suspended in your transmission fluid. After 50,000 or 60,000 miles, your fluid's not clear anymore. It's dark brown or black and it's got metal shavings floating around in it. That contaminated fluid's circulating through your transmission and grinding up the synchros faster. The fluid also breaks down from heat. If you're driving hard or you live somewhere hot, the fluid gets cooked. It loses viscosity, it doesn't lubricate as well, and your synchros start wearing out. That's why second gear grinds. The synchro ring's worn down and it can't match the gear speed fast enough. You force the shifter and you're grinding metal on metal. Fresh fluid fixes that. Royal Purple Synchromax doesn't just replace the old contaminated fluid. It's a full synthetic that's formulated specifically for the friction characteristics of brass synchros rubbing on steel gears. It works better than Honda MTF ever did.

Royal Purple Synchromax vs. Honda MTF

Honda MTF is a conventional petroleum-based fluid. It's decent. Honda wouldn't spec garbage fluid for their transmissions. But it's not synthetic and it breaks down. If you live in Minnesota and it's 10 degrees outside, Honda MTF turns into molasses. Your shifter's stiff, you're crunching into second gear, and you're waiting five minutes for the transmission to warm up before it'll shift normally. If you live in Arizona and it's 115 degrees outside, or if you just finished a track session and your transmission's at 200 degrees, Honda MTF thins out. The synchros don't get the lubrication they need and shifts get sloppy. Royal Purple Synchromax is a full synthetic. The base stock's polyalphaolefin (PAO) synthetic oil. PAO doesn't break down from heat like petroleum does. The viscosity stays consistent whether it's freezing cold or track-day hot. Royal Purple also adds friction modifiers that are specifically calibrated for brass-on-steel synchro engagement. Too much friction modifier and the synchros slip. Not enough and you get notchy grinding shifts. Synchromax gets it right. You get smooth positive shifts in any weather without the synchros wearing out prematurely.

It Actually Works in Cold Weather

If you've ever driven your Civic or Integra in winter, you know the pain. It's 15 degrees outside, you start the car, you try to shift into first gear and the shifter doesn't want to move. You force it. You get it into gear. You start driving. You go to shift into second and it grinds unless you wait three full seconds between first and second. That's cold thick transmission fluid. The synchros can't engage because the fluid's too thick to let them spin freely. You're sitting there double-clutching like it's 1950 just to get second gear to go in without grinding. Royal Purple rates Synchromax to -40°F. That doesn't mean it's thin as water at -40 but it means the fluid's still flowing and the synchros can still work. We had a customer in Wisconsin running Honda MTF who switched to Synchromax and he said it was like having a different transmission in winter. First gear engaged normally. Second gear went in clean without waiting or double-clutching. The shifter felt normal instead of like moving a crowbar through frozen grease. If you live somewhere that actually gets winter, you'll notice the difference the first cold morning after you change the fluid.

How to Change Your Transmission Fluid Properly

Don't just drain and fill when the transmission's cold. You'll leave a quart of old nasty fluid sitting in the transmission case because cold fluid doesn't flow. Here's how you do it right. Drive the car for 10 or 15 minutes. Get the transmission warm. Warm fluid's thin and it flows out of the drain hole fast. You'll drain way more of the old fluid out if it's warm. Pull the car up on ramps or jack it up and put it on jack stands. Find the transmission drain plug. It's on the bottom of the transmission case, usually a 17mm or 19mm bolt with a washer. Put a drain pan under it and pull the plug. Let it drain for at least 10 minutes. Don't rush it. When it stops dripping, reinstall the drain plug with a new crush washer if you've got one. Find the fill hole. It's on the side of the transmission, usually a 17mm bolt. Pull that bolt out. Use a fluid pump or a funnel with a hose and start filling. Your transmission takes somewhere between 1.9 and 2.3 quarts depending on the model. Keep filling until fluid starts coming back out of the fill hole. That's how you know it's full. Reinstall the fill plug. Done. Start the car, run through the gears a few times, then check the fill hole again to make sure you're still topped off.

What You Get

• Royal Purple Synchromax manual transmission fluid - 1 quart bottle
• Part number: 06512
• Full synthetic PAO (polyalphaolefin) base stock
• Friction modifiers calibrated for brass synchros on steel gears
• Temperature range: -40°F to 300°F+
• Replaces Honda MTF, GM Synchromesh, and most OEM manual transmission fluids
• Works in any synchronized manual transmission
• Sold individually - most Honda/Acura transmissions need 2 bottles

Note: Sold as single 1-quart bottle. Most Honda and Acura manual transmissions take 1.9 to 2.3 quarts, so order 2 bottles. Warm the transmission before draining (drive 10-15 minutes) so old fluid flows out completely. Fill until fluid comes back out of the fill hole - that's how you know it's full. Some people run Synchromax year-round. Some run it in winter only and switch back to Honda MTF in summer. Either works. Change your transmission fluid every 30,000-50,000 miles or when shifts start getting notchy. If you just bought a used car and you don't know the fluid change history, change it now.