How to Fix a Wobbly Toilet: Tighten Bolts, Shim the Base, and Check the Wax Ring

A rocking toilet cracks its own wax seal a little more with every flush — this is a repair worth doing today, not next

A rocking toilet cracks its own wax seal a little more with every flush — this is a repair worth doing today, not next month.

What You Need

• Toilet wax ring — replace any time the toilet is lifted from the floor
• Toilet tee bolt replacement set — brass bolts resist corrosion better than zinc-plated steel
• Toilet shims — plastic shims for leveling a toilet on uneven floors
• Toilet flange repair kit — for cracked or broken flanges that cannot hold tee bolts
• Adjustable wrench — to tighten tee bolt nuts without cracking the china
• Plumber’s putty or silicone caulk — for optional base sealing after the toilet is secured

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Step 1: Identify the Cause of the Wobble

Kneel next to the toilet and press down on the front left and front right corners of the base alternately. Determine where the rocking originates:

Wobble from one corner only. This usually indicates an uneven floor rather than a loose bolt problem. The floor may have settled, or a tile may be slightly higher or lower under one corner of the base.

Wobble that feels loose in all directions. This suggests the tee bolts are loose or the toilet flange is broken. The toilet is not properly anchored at all.

Wobble accompanied by water at the base. The wax ring seal is already compromised. You must lift the toilet, replace the wax ring, and address the bolts and flange before reinstalling.

Wobble with a sulfur or sewage smell. The wax ring is failing and sewer gas is escaping around the base. This requires lifting and reseating the toilet promptly.

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Step 2: Try Tightening the Tee Bolts First

Pop the plastic caps at the base of the toilet on both sides by prying them up with a flat-head screwdriver. Under each cap is a tee bolt nut. Using an adjustable wrench, snug each nut down — alternate between left and right so you are not pulling the base unevenly. Remember: firm, not torqued. If the toilet stops rocking after tightening the nuts, replace the caps and you are done.

If a nut spins without tightening — the bolt is spinning inside the flange slot — or if you cannot get the nut to engage, the tee bolt is stripped or damaged and must be replaced. Proceed to Step 3 or 4 as applicable.

Testing after tightening. Sit on the toilet and shift your weight side to side. If it is now solid with zero rock, the tee bolt tightening resolved the issue. If there is still movement, move on to shimming or flange inspection.

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Step 3: Shim the Base for an Uneven Floor

If the toilet rocks from a floor levelness issue rather than a loose bolt, shimming is the fix. You do not need to lift the toilet for this.

Find the low point. Rock the toilet until you identify which corner or section of the base lifts off the floor. Slide a piece of paper or a thin plastic shim under the rocking side — you will feel it drag when the toilet rocks down onto it.

Insert plastic toilet shims. Slide a plastic toilet shim into the gap under the rocking side. Push it in until you feel resistance — the shim should be snug without forcing it. Test by rocking the toilet again. If it still moves, add a second shim or push the first one slightly deeper.

Alternate shim placement. Some toilets rock diagonally — from one front corner to the opposite rear corner. Place shims on both sides of the rocking axis: slide one shim in from the left gap and one from the right gap, offset from each other, until the toilet sits completely flat with no movement.

Trim the shims. Once the toilet is stable, use a utility knife to score the exposed shim material flush with the toilet base edge, then snap it off. The flush trim prevents the shim from being kicked loose accidentally.

Secure with caulk. Apply a thin bead of clear silicone caulk along the front and sides of the toilet base (not the back), pressing it over the shim edges to lock them in place. Wipe the excess with a damp cloth. Leave a small gap at the rear so any future water leak is visible rather than hidden.

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Step 4: Inspect and Repair the Toilet Flange

If tightening the tee bolts did not work — if the bolts spin or there is simply no solid engagement — you need to look at the toilet flange. This step requires shutting off the water supply and lifting the toilet.

Shut off the water. Turn the shut-off valve on the supply line behind the toilet clockwise until fully closed. Flush the toilet to empty the tank and bowl. Use a sponge to remove any remaining water from the bowl and tank.

Disconnect the supply line. Unscrew the supply line from the bottom of the fill valve on the tank. Have a small bucket ready — a cup or two of water will drain.

Remove the tee bolt nuts and lift the toilet. Unscrew both tee bolt nuts completely and set them aside. Lift the toilet straight up — toilet bases weigh 50 to 100 pounds, so get a helper if possible. Set the toilet on its side on an old towel.

Inspect the flange. Look at the toilet flange — the plastic or metal ring set into the floor around the drain pipe. You are looking for:

• Cracks radiating outward from the tee bolt slots
• Tee bolt slots that are broken off so the bolt cannot anchor
• A flange that is rocking because its mounting screws have pulled loose from the subfloor
• A flange that sits too low (more than 1/4 inch below the finished floor surface)

Inspect the old wax ring. Note its condition. A good wax ring that was properly compressed will look like a flat pancake — spread evenly against both the toilet horn and the flange. A failed wax ring will have gaps, cracks, or will appear only partially compressed. Scrape all old wax off both the toilet horn and the flange using a putty knife — remove every trace of old wax before installing the new ring.

Repair a cracked flange. Install a toilet flange repair kit by sliding the metal repair ring over the existing flange. Position the new tee bolt slots over solid sections of the existing flange or directly on the repair ring. Secure the repair ring to the subfloor using the provided screws. This stabilizes the toilet without requiring drain pipe replacement.

Repair a flange too low. If the flange sits more than 1/4 inch below the finished floor, use a stacking wax ring (a double-thickness wax ring) or a wax-free toilet seal that can be shimmed to the correct height. A properly positioned flange should sit at or slightly above the finished floor level.

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Step 5: Reinstall the Toilet with a New Wax Ring

Whether you lifted the toilet to inspect the flange or confirmed the wax ring was failing, reinstall with a fresh wax ring every time the toilet is lifted — do not attempt to reuse an old one.

Position new tee bolts. Slide new tee bolts into the flange slots with the head captured in the slot. Position one bolt at each side, with the threaded end pointing straight up. Some plumbers put a small amount of plumber’s putty around the head of each bolt to hold it upright while positioning the toilet.

Install the wax ring. Press the wax ring (wax side down, horn side up) onto the toilet outlet horn at the bottom of the bowl. Do not press it onto the flange — mounting it on the toilet ensures the wax is centered when you lower the toilet.

Lower the toilet. With a helper, carry the toilet over the drain and slowly lower it so the tee bolts pass through the bolt holes in the toilet base. Once the toilet is over the bolts, press straight down firmly and evenly until the toilet base contacts the floor. Do not rock or twist — press straight down. The wax compresses to form the seal. You only get one chance to seat it correctly; repositioning after setting breaks the seal.

Tighten the tee bolt nuts. Alternate sides: snug left, snug right, left again, right again — do not tighten one side completely before starting the other. Stop when the toilet has zero movement and you feel solid resistance. Snap the decorative caps over the nuts.

Reconnect the supply line and test. Hand-tighten the supply line, turn the shut-off valve back on, and flush three times. Inspect around the base carefully for any water. Sit on the toilet and test for wobble.

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Related Reading

• How to Install a Toilet — full toilet removal and installation guide from start to finish
• How to Fix Low Water Pressure — diagnose weak flow at the toilet fill valve or throughout the bathroom
• How to Unclog a Toilet — related plumbing repair and maintenance guides