diff --git a/lib/matplotlib/colorbar.py b/lib/matplotlib/colorbar.py
index c23aa5cf4fd5..4f9f04c324d4 100644
--- a/lib/matplotlib/colorbar.py
+++ b/lib/matplotlib/colorbar.py
@@ -222,96 +222,41 @@ def _set_ticks_on_axis_warn(*args, **kw):
     cbook._warn_external("Use the colorbar set_ticks() method instead.")
 
 
-class _ColorbarAutoLocator(ticker.MaxNLocator):
-    """
-    AutoLocator for Colorbar
-
-    This locator is just a `.MaxNLocator` except the min and max are
-    clipped by the norm's min and max (i.e. vmin/vmax from the
-    image/pcolor/contour object).  This is necessary so ticks don't
-    extrude into the "extend regions".
-    """
-
-    def __init__(self, colorbar):
-        """
-        This ticker needs to know the *colorbar* so that it can access
-        its *vmin* and *vmax*.  Otherwise it is the same as
-        `~.ticker.AutoLocator`.
-        """
-
-        self._colorbar = colorbar
-        nbins = 'auto'
-        steps = [1, 2, 2.5, 5, 10]
-        super().__init__(nbins=nbins, steps=steps)
-
-    def tick_values(self, vmin, vmax):
-        # flip if needed:
-        if vmin > vmax:
-            vmin, vmax = vmax, vmin
-        vmin = max(vmin, self._colorbar.norm.vmin)
-        vmax = min(vmax, self._colorbar.norm.vmax)
-        ticks = super().tick_values(vmin, vmax)
-        rtol = (vmax - vmin) * 1e-10
-        return ticks[(ticks >= vmin - rtol) & (ticks <= vmax + rtol)]
-
-
-class _ColorbarAutoMinorLocator(ticker.AutoMinorLocator):
-    """
-    AutoMinorLocator for Colorbar
-
-    This locator is just a `.AutoMinorLocator` except the min and max are
-    clipped by the norm's min and max (i.e. vmin/vmax from the
-    image/pcolor/contour object).  This is necessary so that the minorticks
-    don't extrude into the "extend regions".
-    """
-
-    def __init__(self, colorbar, n=None):
-        """
-        This ticker needs to know the *colorbar* so that it can access
-        its *vmin* and *vmax*.
-        """
+class _LocatorWrapper():
+    def __init__(self, parentLocator, colorbar=None):
+        self.__class__ = type(parentLocator.__class__.__name__,
+                              (self.__class__, parentLocator.__class__),
+                              {})
+        self.__dict__ = parentLocator.__dict__
         self._colorbar = colorbar
-        self.ndivs = n
-        super().__init__(n=None)
 
-    def __call__(self):
+    def _trim_ticks(self, ticks):
+        if len(ticks) == 0:
+            return ticks
         vmin = self._colorbar.norm.vmin
         vmax = self._colorbar.norm.vmax
-        ticks = super().__call__()
-        rtol = (vmax - vmin) * 1e-10
-        return ticks[(ticks >= vmin - rtol) & (ticks <= vmax + rtol)]
-
-
-class _ColorbarLogLocator(ticker.LogLocator):
-    """
-    LogLocator for Colorbarbar
-
-    This locator is just a `.LogLocator` except the min and max are
-    clipped by the norm's min and max (i.e. vmin/vmax from the
-    image/pcolor/contour object).  This is necessary so ticks don't
-    extrude into the "extend regions".
+        if hasattr(self._colorbar.norm, '_scale'):
+            trans = self._colorbar.norm._scale._transform.transform
+        else:
+            trans = mtransforms.IdentityTransform().transform
+        rtol = (trans(vmax) - trans(vmin)) * 1e-10
+        good = ((trans(ticks) >= trans(vmin) - rtol) &
+                     (trans(ticks) <= trans(vmax) + rtol))
+        return ticks[good]
 
-    """
-    def __init__(self, colorbar, *args, **kwargs):
-        """
-        This ticker needs to know the *colorbar* so that it can access
-        its *vmin* and *vmax*.  Otherwise it is the same as
-        `~.ticker.LogLocator`.  The ``*args`` and ``**kwargs`` are the
-        same as `~.ticker.LogLocator`.
-        """
-        self._colorbar = colorbar
-        super().__init__(*args, **kwargs)
+    def __call__(self):
+        ticks = super().__call__()
+        return self._trim_ticks(np.asarray(ticks))
 
     def tick_values(self, vmin, vmax):
-        if vmin > vmax:
-            vmin, vmax = vmax, vmin
-        vmin = max(vmin, self._colorbar.norm.vmin)
-        vmax = min(vmax, self._colorbar.norm.vmax)
+        if vmin is not None and vmax is not None and vmin > vmax:
+            vmax, vmin = vmin, vmax
+        if vmin is not None:
+            vmin = max(vmin, self._colorbar.norm.vmin)
+        if vmax is not None:
+            vmax = min(vmax, self._colorbar.norm.vmax)
         ticks = super().tick_values(vmin, vmax)
-        rtol = (np.log10(vmax) - np.log10(vmin)) * 1e-10
-        ticks = ticks[(np.log10(ticks) >= np.log10(vmin) - rtol) &
-                      (np.log10(ticks) <= np.log10(vmax) + rtol)]
-        return ticks
+        return self._trim_ticks(np.asarray(ticks))
 
 
 class _ColorbarSpine(mspines.Spine):
@@ -488,7 +433,9 @@ def __init__(self, ax, cmap=None,
         self.ax.add_collection(self.dividers)
 
         self.locator = None
+        self.minorlocator = None
         self.formatter = None
+        self.minorformatter = None
         self._manual_tick_data_values = None
         self.__scale = None  # linear, log10 for now.  Hopefully more?
 
@@ -510,6 +457,18 @@ def __init__(self, ax, cmap=None,
             self.formatter = format  # Assume it is a Formatter or None
         self.draw_all()
 
+    def _long_axis(self):
+        if self.orientation == 'vertical':
+            return self.ax.yaxis
+        else:
+            return self.ax.xaxis
+
+    def _short_axis(self):
+        if self.orientation == 'vertical':
+            return self.ax.xaxis
+        else:
+            return self.ax.yaxis
+
     def _extend_lower(self):
         """Return whether the lower limit is open ended."""
         return self.extend in ('both', 'min')
@@ -552,19 +511,16 @@ def config_axis(self):
 
     def _config_axis(self):
         """Set up long and short axis."""
-        ax = self.ax
         if self.orientation == 'vertical':
-            long_axis, short_axis = ax.yaxis, ax.xaxis
             if mpl.rcParams['ytick.minor.visible']:
                 self.minorticks_on()
         else:
-            long_axis, short_axis = ax.xaxis, ax.yaxis
             if mpl.rcParams['xtick.minor.visible']:
                 self.minorticks_on()
-        long_axis.set(label_position=self.ticklocation,
-                      ticks_position=self.ticklocation)
-        short_axis.set_ticks([])
-        short_axis.set_ticks([], minor=True)
+        self._long_axis().set(label_position=self.ticklocation,
+                              ticks_position=self.ticklocation)
+        self._short_axis().set_ticks([])
+        self._short_axis().set_ticks([], minor=True)
         self.stale = True
 
     def _get_ticker_locator_formatter(self):
@@ -577,30 +533,19 @@ def _get_ticker_locator_formatter(self):
         """
         locator = self.locator
         formatter = self.formatter
-        if locator is None:
-            if self.boundaries is None:
-                if isinstance(self.norm, colors.NoNorm):
-                    nv = len(self._values)
-                    base = 1 + int(nv / 10)
-                    locator = ticker.IndexLocator(base=base, offset=0)
-                elif isinstance(self.norm, colors.BoundaryNorm):
-                    b = self.norm.boundaries
-                    locator = ticker.FixedLocator(b, nbins=10)
-                elif isinstance(self.norm, colors.LogNorm):
-                    locator = _ColorbarLogLocator(self)
-                elif isinstance(self.norm, colors.SymLogNorm):
-                    # The subs setting here should be replaced
-                    # by logic in the locator.
-                    locator = ticker.SymmetricalLogLocator(
-                                      subs=np.arange(1, 10),
-                                      linthresh=self.norm.linthresh,
-                                      base=10)
-                else:
-                    if mpl.rcParams['_internal.classic_mode']:
-                        locator = ticker.MaxNLocator()
-                    else:
-                        locator = _ColorbarAutoLocator(self)
-            else:
+        minorlocator = self.minorlocator
+        minorformatter = self.minorformatter
+
+        if (self.boundaries is None and
+                not isinstance(self.norm, colors.BoundaryNorm)):
+            if locator is None:
+                locator = _LocatorWrapper(
+                    self._long_axis().get_major_locator(), colorbar=self)
+            if minorlocator is None:
+                minorlocator = _LocatorWrapper(
+                    self._long_axis().get_minor_locator(), colorbar=self)
+        else:
+            if locator is None:
                 b = self._boundaries[self._inside]
                 locator = ticker.FixedLocator(b, nbins=10)
 
@@ -616,9 +561,9 @@ def _get_ticker_locator_formatter(self):
             formatter = self.formatter
 
         self.locator = locator
+        self.minorlocator = minorlocator
         self.formatter = formatter
-        _log.debug('locator: %r', locator)
-        return locator, formatter
+        self.minorformatter = minorformatter
 
     def _use_auto_colorbar_locator(self):
         """
@@ -626,8 +571,7 @@ def _use_auto_colorbar_locator(self):
         one.  (check is used twice so factored out here...)
         """
         contouring = self.boundaries is not None and self.spacing == 'uniform'
-        return (type(self.norm) in [colors.Normalize, colors.LogNorm] and
-                not contouring)
+        return (hasattr(self.norm, '_scale') and not contouring)
 
     def _reset_locator_formatter_scale(self):
         """
@@ -636,14 +580,16 @@ def _reset_locator_formatter_scale(self):
         the mappable normal gets changed: Colorbar.update_normal)
         """
         self.locator = None
+        self.minorlocator = None
         self.formatter = None
-        if isinstance(self.norm, colors.LogNorm):
-            # *both* axes are made log so that determining the
-            # mid point is easier.
-            self.ax.set_xscale('log')
-            self.ax.set_yscale('log')
-            self.minorticks_on()
-            self.__scale = 'log'
+        if hasattr(self.norm, '_scale'):
+            self.ax.set_xscale(self.norm._scale.name,
+                               **self.norm._scale._kwargs)
+            self.ax.set_yscale(self.norm._scale.name,
+                               **self.norm._scale._kwargs)
+            self.ax.xaxis._scale = self.norm._scale
+            self.ax.yaxis._scale = self.norm._scale
+            self.__scale = self.norm._scale.name
         else:
             self.ax.set_xscale('linear')
             self.ax.set_yscale('linear')
@@ -659,18 +605,22 @@ def update_ticks(self):
         """
         ax = self.ax
         # Get the locator and formatter; defaults to self.locator if not None.
-        locator, formatter = self._get_ticker_locator_formatter()
-        long_axis = ax.yaxis if self.orientation == 'vertical' else ax.xaxis
+        self._get_ticker_locator_formatter()
         if self._use_auto_colorbar_locator():
-            _log.debug('Using auto colorbar locator %r on colorbar', locator)
-            long_axis.set_major_locator(locator)
-            long_axis.set_major_formatter(formatter)
+            _log.debug('Using auto colorbar locator %r on colorbar',
+                       self.locator)
+            self._long_axis().set_major_locator(self.locator)
+            if self.minorlocator is not None:
+                self._long_axis().set_minor_locator(self.minorlocator)
+            self._long_axis().set_major_formatter(self.formatter)
         else:
             _log.debug('Using fixed locator on colorbar')
-            ticks, ticklabels, offset_string = self._ticker(locator, formatter)
-            long_axis.set_ticks(ticks)
-            long_axis.set_ticklabels(ticklabels)
-            long_axis.get_major_formatter().set_offset_string(offset_string)
+            ticks, ticklabels, offset_string = self._ticker(self.locator,
+                                                            self.formatter)
+            self._long_axis().set_ticks(ticks)
+            self._long_axis().set_ticklabels(ticklabels)
+            fmt = self._long_axis().get_major_formatter()
+            fmt.set_offset_string(offset_string)
 
     def set_ticks(self, ticks, update_ticks=True):
         """
@@ -700,10 +650,7 @@ def set_ticks(self, ticks, update_ticks=True):
     def get_ticks(self, minor=False):
         """Return the x ticks as a list of locations."""
         if self._manual_tick_data_values is None:
-            ax = self.ax
-            long_axis = (
-                ax.yaxis if self.orientation == 'vertical' else ax.xaxis)
-            return long_axis.get_majorticklocs()
+            return self._long_axis().get_majorticklocs()
         else:
             # We made the axes manually, the old way, and the ylim is 0-1,
             # so the majorticklocs are in those units, not data units.
@@ -729,21 +676,23 @@ def minorticks_on(self):
         Turn the minor ticks of the colorbar on without extruding
         into the "extend regions".
         """
-        ax = self.ax
-        long_axis = ax.yaxis if self.orientation == 'vertical' else ax.xaxis
 
-        if long_axis.get_scale() == 'log':
-            long_axis.set_minor_locator(_ColorbarLogLocator(self, base=10.,
-                                                            subs='auto'))
-            long_axis.set_minor_formatter(ticker.LogFormatterSciNotation())
-        else:
-            long_axis.set_minor_locator(_ColorbarAutoMinorLocator(self))
+        # get the default from the parent so we don't duplicate logic.
+        self.ax.minorticks_on()
+        self._short_axis().set_minor_locator(ticker.NullLocator())
+
+        # now wrap the default:
+        loc = _LocatorWrapper(self._long_axis().get_minor_locator(),
+                              colorbar=self)
+
+        self.minorlocator = loc
+        self._long_axis().set_minor_locator(loc)
 
     def minorticks_off(self):
         """Turn the minor ticks of the colorbar off."""
         ax = self.ax
-        long_axis = ax.yaxis if self.orientation == 'vertical' else ax.xaxis
-        long_axis.set_minor_locator(ticker.NullLocator())
+        self.minorlocator = ticker.NullLocator()
+        self._long_axis().set_minor_locator(self.minorlocator)
 
     def set_label(self, label, *, loc=None, **kwargs):
         """
@@ -1270,6 +1219,7 @@ def update_bruteforce(self, mappable):
         # colorbar methods, those changes will be lost.
         self.ax.cla()
         self.locator = None
+        self.minorlocator = None
         self.formatter = None
 
         # clearing the axes will delete outline, patch, solids, and lines:
diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
index 0004d89a3a89..92e0d595c84e 100644
--- a/lib/matplotlib/colors.py
+++ b/lib/matplotlib/colors.py
@@ -1096,6 +1096,7 @@ def __init__(self, vmin=None, vmax=None, clip=False):
         self.vmin = _sanitize_extrema(vmin)
         self.vmax = _sanitize_extrema(vmax)
         self.clip = clip
+        self._scale = scale.LinearScale(axis=None)
 
     @staticmethod
     def process_value(value):
@@ -1250,6 +1251,7 @@ def __init__(self, vcenter, vmin=None, vmax=None):
         if vcenter is not None and vmin is not None and vcenter <= vmin:
             raise ValueError('vmin, vcenter, and vmax must be in '
                              'ascending order')
+        self._scale = scale.LinearScale(axis=None)
 
     def autoscale_None(self, A):
         """
@@ -1316,6 +1318,7 @@ def __init__(self, vcenter=0, halfrange=None, clip=False):
         # calling the halfrange setter to set vmin and vmax
         self.halfrange = halfrange
         self.clip = clip
+        self._scale = scale.LinearScale(axis=None)
 
     def _set_vmin_vmax(self):
         """
diff --git a/lib/matplotlib/scale.py b/lib/matplotlib/scale.py
index e5e9d012f3b0..bdebab5d6ae9 100644
--- a/lib/matplotlib/scale.py
+++ b/lib/matplotlib/scale.py
@@ -53,6 +53,7 @@ def __init__(self, axis):
         be used: a single scale object should be usable by multiple
         `~matplotlib.axis.Axis`\es at the same time.
         """
+        self._kwargs = dict()
 
     def get_transform(self):
         """
@@ -92,6 +93,8 @@ def __init__(self, axis):
         # the docstring of Axis.set_scale.
         """
         """
+        self._transform = IdentityTransform()
+        self._kwargs = dict()
 
     def set_default_locators_and_formatters(self, axis):
         # docstring inherited
@@ -110,7 +113,7 @@ def get_transform(self):
         Return the transform for linear scaling, which is just the
         `~matplotlib.transforms.IdentityTransform`.
         """
-        return IdentityTransform()
+        return self._transform
 
 
 class FuncTransform(Transform):
@@ -173,6 +176,7 @@ def forward(values: array-like) -> array-like
         forward, inverse = functions
         transform = FuncTransform(forward, inverse)
         self._transform = transform
+        self._kwargs = {'functions': functions}
 
     def get_transform(self):
         """Return the `.FuncTransform` associated with this scale."""
@@ -296,6 +300,7 @@ def __init__(*, base=10, subs=None, nonpositive="clip"):
         base, subs, nonpositive = __init__(**kwargs)
         self._transform = LogTransform(base, nonpositive)
         self.subs = subs
+        self._kwargs = kwargs
 
     base = property(lambda self: self._transform.base)
 
@@ -349,6 +354,7 @@ def forward(values: array-like) -> array-like
         forward, inverse = functions
         self.subs = None
         self._transform = FuncTransform(forward, inverse) + LogTransform(base)
+        self._kwargs = {'functions': functions, 'base': base}
 
     @property
     def base(self):
@@ -476,6 +482,7 @@ def __init__(*, base=10, linthresh=2, subs=None, linscale=1):
         base, linthresh, subs, linscale = __init__(**kwargs)
         self._transform = SymmetricalLogTransform(base, linthresh, linscale)
         self.subs = subs
+        self._kwargs = kwargs
 
     base = property(lambda self: self._transform.base)
     linthresh = property(lambda self: self._transform.linthresh)
@@ -569,6 +576,8 @@ def __init__(self, axis, nonpositive='mask', *,
         self._transform = LogitTransform(nonpositive)
         self._use_overline = use_overline
         self._one_half = one_half
+        self._kwargs = {'nonpositive': nonpositive, 'one_half': one_half,
+                        'use_overline': use_overline}
 
     def get_transform(self):
         """Return the `.LogitTransform` associated with this scale."""
diff --git a/lib/matplotlib/tests/baseline_images/test_colorbar/colorbar_single_scatter.png b/lib/matplotlib/tests/baseline_images/test_colorbar/colorbar_single_scatter.png
index 63a58245f7e0..cce7fcd8e029 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_colorbar/colorbar_single_scatter.png and b/lib/matplotlib/tests/baseline_images/test_colorbar/colorbar_single_scatter.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout11.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout11.png
index 514bf02ce13c..ad11fe7ec370 100644
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diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout11rat.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout11rat.png
index b674803ba2e8..1b6fca0e4653 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout11rat.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout11rat.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout13.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout13.png
index 5889b0583432..f7b0e3e3647d 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout13.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout13.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout14.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout14.png
index e030c3c9f6c1..772213d6e895 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout14.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout14.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout3.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout3.png
index c679609be54e..4ea2fc7968ff 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout3.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout3.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout4.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout4.png
index 2a6e55c08f64..6498f95983bf 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout4.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout4.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout5.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout5.png
index af691c44867d..e9c02567d190 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout5.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout5.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout6.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout6.png
index 6ba96e41a34d..a07d3c8a36de 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout6.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout6.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout8.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout8.png
index 757230e25363..874ebbf837e3 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout8.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout8.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout9.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout9.png
index 59fd2c76c5bc..64296b855637 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout9.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/constrained_layout9.png differ
diff --git a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/test_colorbar_location.png b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/test_colorbar_location.png
index 2ca5a5c29eb1..c8a8eaf94552 100644
Binary files a/lib/matplotlib/tests/baseline_images/test_constrainedlayout/test_colorbar_location.png and b/lib/matplotlib/tests/baseline_images/test_constrainedlayout/test_colorbar_location.png differ
diff --git a/lib/matplotlib/tests/test_colorbar.py b/lib/matplotlib/tests/test_colorbar.py
index bbd1e9c5f590..1ca8b90ef4a7 100644
--- a/lib/matplotlib/tests/test_colorbar.py
+++ b/lib/matplotlib/tests/test_colorbar.py
@@ -9,7 +9,7 @@
 import matplotlib.pyplot as plt
 from matplotlib.colors import (BoundaryNorm, LogNorm, PowerNorm, Normalize,
                                TwoSlopeNorm)
-from matplotlib.colorbar import ColorbarBase, _ColorbarLogLocator
+from matplotlib.colorbar import ColorbarBase
 from matplotlib.ticker import FixedLocator
 
 
@@ -482,14 +482,13 @@ def test_colorbar_renorm():
     im = ax.imshow(z)
     cbar = fig.colorbar(im)
     np.testing.assert_allclose(cbar.ax.yaxis.get_majorticklocs(),
-                               np.arange(0, 120000.1, 15000))
+                               np.arange(0, 120000.1, 20000))
 
     cbar.set_ticks([1, 2, 3])
     assert isinstance(cbar.locator, FixedLocator)
 
     norm = LogNorm(z.min(), z.max())
     im.set_norm(norm)
-    assert isinstance(cbar.locator, _ColorbarLogLocator)
     np.testing.assert_allclose(cbar.ax.yaxis.get_majorticklocs(),
                                np.logspace(-8, 5, 14))
     # note that set_norm removes the FixedLocator...
@@ -514,13 +513,13 @@ def test_colorbar_format():
     im = ax.imshow(z)
     cbar = fig.colorbar(im, format='%4.2e')
     fig.canvas.draw()
-    assert cbar.ax.yaxis.get_ticklabels()[4].get_text() == '6.00e+04'
+    assert cbar.ax.yaxis.get_ticklabels()[4].get_text() == '8.00e+04'
 
     # make sure that if we change the clim of the mappable that the
     # formatting is *not* lost:
     im.set_clim([4, 200])
     fig.canvas.draw()
-    assert cbar.ax.yaxis.get_ticklabels()[4].get_text() == '8.00e+01'
+    assert cbar.ax.yaxis.get_ticklabels()[2].get_text() == '1.50e+02'
 
     # but if we change the norm:
     im.set_norm(LogNorm(vmin=0.1, vmax=10))
diff --git a/lib/matplotlib/tests/test_constrainedlayout.py b/lib/matplotlib/tests/test_constrainedlayout.py
index 7ea92a160c11..d2c62019ab30 100644
--- a/lib/matplotlib/tests/test_constrainedlayout.py
+++ b/lib/matplotlib/tests/test_constrainedlayout.py
@@ -51,8 +51,6 @@ def test_constrained_layout2():
 @image_comparison(['constrained_layout3.png'])
 def test_constrained_layout3():
     """Test constrained_layout for colorbars with subplots"""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig, axs = plt.subplots(2, 2, constrained_layout=True)
     for nn, ax in enumerate(axs.flat):
@@ -67,8 +65,6 @@ def test_constrained_layout3():
 @image_comparison(['constrained_layout4.png'])
 def test_constrained_layout4():
     """Test constrained_layout for a single colorbar with subplots"""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig, axs = plt.subplots(2, 2, constrained_layout=True)
     for ax in axs.flat:
@@ -82,8 +78,6 @@ def test_constrained_layout5():
     Test constrained_layout for a single colorbar with subplots,
     colorbar bottom
     """
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig, axs = plt.subplots(2, 2, constrained_layout=True)
     for ax in axs.flat:
@@ -96,8 +90,6 @@ def test_constrained_layout5():
 @image_comparison(['constrained_layout6.png'], tol=0.002)
 def test_constrained_layout6():
     """Test constrained_layout for nested gridspecs"""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig = plt.figure(constrained_layout=True)
     gs = fig.add_gridspec(1, 2, figure=fig)
@@ -139,8 +131,6 @@ def test_constrained_layout7():
 @image_comparison(['constrained_layout8.png'])
 def test_constrained_layout8():
     """Test for gridspecs that are not completely full"""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig = plt.figure(figsize=(10, 5), constrained_layout=True)
     gs = gridspec.GridSpec(3, 5, figure=fig)
@@ -169,8 +159,6 @@ def test_constrained_layout8():
 @image_comparison(['constrained_layout9.png'])
 def test_constrained_layout9():
     """Test for handling suptitle and for sharex and sharey"""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig, axs = plt.subplots(2, 2, constrained_layout=True,
                             sharex=False, sharey=False)
@@ -195,8 +183,6 @@ def test_constrained_layout10():
 @image_comparison(['constrained_layout11.png'])
 def test_constrained_layout11():
     """Test for multiple nested gridspecs"""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig = plt.figure(constrained_layout=True, figsize=(13, 3))
     gs0 = gridspec.GridSpec(1, 2, figure=fig)
@@ -217,8 +203,6 @@ def test_constrained_layout11():
 @image_comparison(['constrained_layout11rat.png'])
 def test_constrained_layout11rat():
     """Test for multiple nested gridspecs with width_ratios"""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig = plt.figure(constrained_layout=True, figsize=(10, 3))
     gs0 = gridspec.GridSpec(1, 2, figure=fig, width_ratios=[6, 1])
@@ -261,8 +245,6 @@ def test_constrained_layout12():
 @image_comparison(['constrained_layout13.png'], tol=2.e-2)
 def test_constrained_layout13():
     """Test that padding works."""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig, axs = plt.subplots(2, 2, constrained_layout=True)
     for ax in axs.flat:
@@ -274,8 +256,6 @@ def test_constrained_layout13():
 @image_comparison(['constrained_layout14.png'])
 def test_constrained_layout14():
     """Test that padding works."""
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
 
     fig, axs = plt.subplots(2, 2, constrained_layout=True)
     for ax in axs.flat:
@@ -402,9 +382,6 @@ def test_colorbar_location():
     Test that colorbar handling is as expected for various complicated
     cases...
     """
-    # Remove this line when this test image is regenerated.
-    plt.rcParams['pcolormesh.snap'] = False
-
     fig, axs = plt.subplots(4, 5, constrained_layout=True)
     for ax in axs.flat:
         pcm = example_pcolor(ax)
diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
index 21097e282c73..54ae444bb1d3 100644
--- a/lib/matplotlib/ticker.py
+++ b/lib/matplotlib/ticker.py
@@ -2162,8 +2162,7 @@ def set_params(self, **kwargs):
             self._nbins = kwargs.pop('nbins')
             if self._nbins != 'auto':
                 self._nbins = int(self._nbins)
-        if 'symmetric' in kwargs:
-            self._symmetric = kwargs.pop('symmetric')
+        self._symmetric = kwargs.pop('symmetric', False)
         if 'prune' in kwargs:
             prune = kwargs.pop('prune')
             _api.check_in_list(['upper', 'lower', 'both', None], prune=prune)
diff --git a/lib/mpl_toolkits/tests/test_axes_grid.py b/lib/mpl_toolkits/tests/test_axes_grid.py
index 2c2a9e785a96..fbebb1f8cb87 100644
--- a/lib/mpl_toolkits/tests/test_axes_grid.py
+++ b/lib/mpl_toolkits/tests/test_axes_grid.py
@@ -63,4 +63,3 @@ def test_imagegrid():
     ax = grid[0]
     im = ax.imshow([[1, 2]], norm=mpl.colors.LogNorm())
     cb = ax.cax.colorbar(im)
-    assert isinstance(cb.locator, mpl.colorbar._ColorbarLogLocator)