RC10Talk - The Net's Largest Vintage R/C Community

Yes it does..directly. not so for the optima mid.
However you must re use your old 3mm middle bevel pin to hold in the 2 small bevel gears.

Wow excellent find mate,thanks for sharing...

I'm surprised the re-re gears don't fit the Optima Mid diff housings if they do fit the Lazer ZX diff housings. Why doesn't it fit?

AFAIK, the gear diff internals for the Optima are the same ones as those on the Ultima, Optima Mid, Lazer, Tour Force (up to TF4), Mantis, GP-10, SuperTen, etc. chassis. The only things that change are the diff housings, which are adapted to the design of the gearboxes (countergear, conic gear, chain drive, large pitch belt, 3 mm pitch belt; depending on the chassis).

No..the rere gear pitch for diff internals looks different.in fact the tolerances is much better on rere. The re re internals does fit into mid casings..only on the side opposite to the belt pulley. You cant place the short pin into the mids belt pulley because the distance from the outside of the diff to the inside is longer than the lazers. To solve this problem you must lathe off about 0.3mm from one outdrive flange..then you can place the pin in.


Look at these pics. These parts of the mid geardiff has no issues.

Hi guys. Im looking to build some heavy duty gear diffs. Im wondering what to use as fluid / lubricant inside these lazer diffs that will not leak out. I want them to be very stiff, almost not turning, but not completely locked. Ive used white grease inside these before, and when freshly packed, thats about perfect. However, that stuff leaks out pretty quick, soaks the belt, makes a mess, attracts dirt. What else is there that will not leak so bad, and change the diff action after just a few runs? Im going to use the lazer diff cases, and the optima re re gears, for a nice tight fresh start.

Use 200,000 to 500,000 diff oil you're all set, always use harder oil for front diff.

OK, thanks, Ill order some up. The new optima has a bunch of good parts for old cars. Almost worth buying a whole kit and parting it out.