Mixing grease types

[WileyB-J]

It depends on if the greases are compatible really..

But in all things necessary; you will be fine.
Just use more of the grease you plan on sticking with and do your best to open it up sometime during the comp. season to apply more grease.

[JDL]

Clean the old stuff out quick with industrial cleaner/degreaser and start fresh.

[fox46]

As you mentioned, the proper thing to do is to dissassemble the boxes and wash all the old stuff off with mineral spirits or non-chlorinated brake cleaner and then apply your grease of choice. However in the case of the toughboxes, given their light duty you will probably be fine mixing the two. You really don't need much grease on those gears so don't go packing them full of the stuff. Too much grease will cause losses as the gears have to "pump" the stuff around inside. Generally a light coating is all you really need. I would bet your initial application of silicone grease is still plenty sufficient and that you likely don't need to apply any more. I would be far more concerned about bits of grit and dirt in there from the multiple rebuilds without cleaning. Grease makes a great glue for sticking debris to gears.

http://www.machinerylubrication.com/...mixing-greases