Whether your pension can be taxed for child support depends on the manner in which the pension was set up and who administers it, but quite often the proceeds can be taxed for child support. It is unequivocal that Social Security payments can be taxec for child support.
I agree with both gentlemen. I would add that you may be able to petition for modification of your child support payments if too much is being taken out of your monthly amount. Also, if you paid in enough and your children are still minors (meaning you are paying current payments not back pay on children that are now adults) you may have an auxillary payment that would be paid to your children from Social Security. You may be able to request that auxillary payment be accepted as child support. All of this should be done thru the court and not Social Security. You may want to contact a local family law attorney.