AngularJs - forEach scope array - not working

I recognize I am doing something stupid, so please indulge me:

Html:

Filter: <input type="radio" ng-model="Type" value="Rear"> Rear
<input type="radio" ng-model="Type" value="Front"> Front
<br>
Select:
<name-value-select  entry="entry" field="axleType" options="filterTypes"></name-value-select>

Controller:

$scope.$watch('Type', function (Type) {
    $scope.filterTypes = [];
    if ($scope.axleTypes == undefined || $scope.axleTypes == []) {
        $scope.axleTypes = API.GetAxleTypes;
    }
    angular.forEach($scope.axleTypes, function (type) {
        console.log('axleType: ' + type);
        console.log('Type: ' + type);
        if (axleType.Type == Type) {
            this.push(axleType);
        }
    }, $scope.filterTypes);
    $scope.filterTypes.sort(function (a, b) {
        return a.Description.localeCompare(b.Description);
    });
});

I cannot even loop thru the axleTypes array in my watch function. It appears it is not picking up a collection which is odd because it bypasses populating the axleTypes if undefined or [].

I am doing something so stupid, I can't see it.

Update: Per Jason's request

(1) My angular controller:

$scope.entry = {
    Description: ''
};
$scope.Type = 'Front';
$scope.entry.type = '';

$scope.$watch('Type', function (Type) {
    $scope.filterTypes = [];
    $scope.axleTypes = new API.GetAxleTypes(function (axleTypes) {
        angular.forEach($scope.axleTypes, function (axleType) {
            if (axleType.Type == Type) {
                this.push(axleType);
                }
        }, $scope.filterTypes);
    });

    $scope.filterTypes.sort(function (a, b) {
        return a.Description.localeCompare(b.Description);
    });
});

(2)My Html:

Filter: <input type="radio" ng-model="Type" value="Rear"> Rear
<input type="radio" ng-model="Type" value="Front"> Front
<br>
Select:
<name-value-select entry="entry" field="axleType" options="filterTypes"></name-value-select>

No more errors Jason, however, when I toggle the two radio buttons nothing happens, ie, Front Axles still show when I choose the Rear axle radio button. Ughh.