Well, bit the bullet and cleaned the twin titans. 3903 maxx
Used some electrical contact cleaner, gave both a good spray until it came out clear. Used some 3-1 oil on the 2 bushings.
Reinstalled the motors. Seated them tight into the spur gear, then backed off a hair so there was just a fraction of space. Seemed to move freely with no binding. Used a small strip of paper which did not bind and came out nice and crinkled.
I will give it a bit more time to make sure all cleaner is gone then do a test with the batteries.
Is that all? Anything I missed. Does it matter which red or black lead is with which motor?