Changing Tomos transmission fluid

(Redirected from Change gear box oil)

Here are instructions to change the transmission fluid on Tomos mopeds, broken down by engine (A3, A35, A55)

Tomos A3

Fluid to use

There is somewhat of a debate regarding the correct transmission fluid to use for Tomos A3 engines. The contenders in the debate are typically Type A, Type F, 10W30 motorcycle/scooter oil, ND30, or Spectro Golden Gear Lubricant from Heeters. All of these options have received good and bad reviews from someone at some point, and that can make it hard to choose. Type A is harder to find -- most auto parts stores won't have it (people seem to have the best luck finding it at grocery stores, truck stops, and gas stations). Type F and 10W30 are cheap and readily available, and the Spectro Golden, if ordered online, will almost certainly be more expensive. The manual recommends Type A or 10W30, but people have had success with all of these options. Search the forums if you want, or just pick one and try for yourself. If you like it, keep going with it. If you don't like how it works, go to your next choice. (It would be really cool if we could get some reviews or positives/negatives for each of these options in here...)

How to change

Fill and level screws for the A3
(Click for larger image)
  1. Find the drain bolt/plug on the bottom of the transmission. If you were to draw a line from the carb straight down through the engine cases to the ground, the bolt should be on the bottom of the engine cases somewhere around where that line would be.
  2. Get a jar or some sort of fluid-containing receptacle ready.
  3. Start unscrewing the bolt/plug and be prepared for the fluid to start pouring out of the hole
  4. Let the fluid drain. You can tip or shake the moped a bit to make sure you get all the old stuff out. (Also, doing this while the engine/fluid is warm makes the fluid flow better).
  5. When all the old fluid is drained out, screw the drain plug back in, being careful not to strip the hole out.
  6. Unscrew the fill screw (on top of the transmission) and the level screw (on the side of the transmission).
  7. Add whichever fluid you chose to the fill hole until it comes out the level screw hole. Once it stops coming out the level screw hole, you can put both the level screw and the fill screw back in, and you should be good to go.
ALTERNATIVELY: The manual recommends using 220mL of transmission oil. It really probably is best to measure, but if you don't want to, then the level method should be okay.

Tomos A35

Fluid to use

For the Tomos A35 use Type A, or F, Automatic transmission fluid (ATF). You can pick up a bottle at any autoparts store.

How to change

To change gear box oil you drain the plug or bolt at the bottom of the transmission. The bolt on top of your transmission is for filling. There is a phillips head screw on the side unlike the allen heads that actually hold on the gearbox cover. Once you have drained the old oil, and bolted back on the bottom plug, fill new transmission fluid until it leaks out of the side where you have taken the phillips head off. Fill the machine on level ground, sometimes a wood block can be placed under the front tire to make it sit level. Many recommend being very careful NOT to strip out the phillips head on the side, as it is not very strong metal. Use an appropriate sized phillips screwdriver.

Tomos A55

Fluid To Use

For the Tomos A55 use Type A or F automatic transmission fluid (ATF).

How To Change

Refer to the A35 instructions, everything is the same. REMINDER, when taking off any of the bolts holding the gearbox cover on (which is not necessary when changing the transmission oil) please remember to use metric allen keys or else you will strip the bolts.

High Performance Fluid Options (A3 / A35 / A55)

Getting your Tomos to shift more directly and at a higher RPM can be accomplished by changing over to a performance mix for your Tomos. Doing this mixture and setup will make a stock 49cc cylinder behave sluggish at shifting into second gear, so it is recommended for kitted Tomos preferably. See Racing transmission fluid for your Tomos for more information.