15 Common John Deere LT155 Problems (Quick Guide)

When it comes to lawn tractors, John Deere is one of the most reliable brands. The John Deere LT155 model is very popular as well. However, you might face some issues even with this amazing lawn tractor now and then. 

So, what are the common John Deere LT155 problems? The John Deere LT155 can have several problems, including:

  • Stopping after 20 minutes
  • Drive/reverse problems
  • Fuel pump leakage
  • Engine shutting off
  • Transmission problems
  • Fuel issues
  • Starting problems

You might face some other electrical and steering problems with this lawn tractor. To know the reasons and ways to solve them, keep reading. 

John Deere LT155 Engine Problems

While discussing John Deere LT155 common problems, the following engine problems come first.

Problems ReasonsSolutions
Engine Difficult To StartLack of gas in the tank.
Wrong or contaminated fuel.
Broken spark plugs.
Dirty fuel filters.
Trapped air or water on the system. 
Refill the gas.
Use the fresh and correct grade of fuel.
Replace the spark plugs.
Change the fuel filter.
Bleed the trapped air or water. 
Engine OverheatingExcessive load.
Clogged air intake screen.
Wrong engine oil or oil level.
Wrong clearance between the crankshaft and the main bearings.
Avoid putting excessive load on the engine.
Replace the air intake screen.
Refill the engine with the right type of oil.
Adjust the clearance.
Engine Runs UnevenlyClogged cooling fins.
Sticking throttle cable.
Dirty air filter.
Wrong ignition setting.
Clean the cooling fins.
Repair the sticking throttle cable.
Change the air filter.
Adjust the ignition setting.
Engine BackfiresBroken spark plug.
Misadjusted carburetor. 
Damaged inlet or outlet valves. 
Wrong valve clearance.
Worn-out flywheel key.
Replace the spark plug.
Adjust the carburetor.
Replace or repair the valves.
Adjust the valve clearance.
Replace the flywheel key.
Engine KnocksLow engine oil level.
Contaminated or wrong fuel.
Faulty cylinder bore or piston rings.
Clogged cooling fins. 
Faulty connecting rods.
Refill the engine oil.
Change the old fuel with fresh batch.
Repair or replace the broken cylinder parts.
Clean the cooling fins.
Repair or replace the connecting rods. 

Problem 1: Engine Difficult To Start

When it comes to John Deere LT155, the engine won’t start or is difficult to start sometimes. It can mostly happen for simple reasons and is easily fixable.


There can be various reasons behind this problem including, lack of gas in the tank, wrong or contaminated fuel, and broken spark plugs. 

Dirty fuel filters and trapped air or water on the fuel system can be the reasons as well. 


  • First, start with checking the gas level and refill if necessary. 
  • The recommended fuel grade for a John Deere LT155 is unleaded gasoline with an octane rating of 87 or higher. Use the recommended fuel only. 
  • The fuel can get contaminated over time. So, if you haven’t cleaned the fuel tank for a month, clean it now. Drain the old fuel and refill the tank with new fuel of proper fuel grading. 
  • Check the fuel filters and if they are clogged or dirty, replace those. Before removing the old fuel filter, don’t forget to drain the fuel from the fuel line and disconnect the fuel lines.  
  • Bleed the trapped air or water from the fuel system. To do this, open the bleeder valve with an adjustable wrench. Once the air or water is out of the system, making a hissing or gurgling sound, close the bleed valve. 

Next, you have to check the spark plug. Here’s how you do it:

Step 1: Disconnect the spark plug wires from the spark plugs. 

Step 2: Remove the spark plug from the engine using a spark plug socket.

Step 3: Inspect the plug for any visible damage including cracks, breaks, or excessive electrode wear. If there is excessive electrode wear, the spark plug will appear to be burnt. 

Step 4: If the spark plugs are damaged, replace the spark plugs with new ones.

Step 5: Install the new spark plugs making sure that the spark plugs are tightened to the correct torque.

Step 6: Reconnect the spark plug wirings. 

Problem 2: Engine Overheating

If the engine of your John Deere LT155 frequently overheats, it is a serious issue that should be addressed immediately. Otherwise, it can damage the engine further. 


Excessive load on the engine is the primary reason for the engine to overheat. Moreover, clogged air intake screen, wrong engine oil or oil level, and wrong clearance between the crankshaft and the main bearings are some other reasons. 


  • Avoid putting an excessive amount of load on the lawn tractor. 
  • Now, inspect the air intake screen or air filter. If the filter is moderately dirty or clogged, clean it with a brush. If the air filter is severely clogged or torn, you need to replace it with a new air filter. While buying a new air filter, make sure it is compatible with John Deere LT155. XLYZE Air Filter can be a good choice. 
  • Check the oil level of your lawn tractor’s engine. If the oil level is low, refill it. The maximum engine oil capacity for John Deere LT155 is 1.8 L. Do not pour oil more than that. 
  • Make sure you only use the engine oil that is compatible with your lawn tractor. For JD LT155, the recommended oil type is SAE 10W-30, API: SG, SH, SJ. 
  • Inspect the clearance between the crankshaft and the main bearing and compare it to the recommended clearance in the owner’s manual. If the clearance doesn’t match, fix it. The following YouTube video might help you with the process:

Problem 3: Engine Runs Unevenly

Another common problem with John Deere LT155 you might face is the engine runs unevenly or there is an occasional misfire. 


The possible reasons behind this problem are clogged cooling fins, sticking throttle cable, dirty air filter, or wrong ignition setting. 


  • Start with inspecting and changing the air filter. That might solve the problem. 
  • Inspect and clean the cooling fins. If the fins are moderately dirty, a soft brush or washcloth might be enough. But if the fins have accumulated stubborn dirt, you should use a can of compressed air to blow out any debris. 
  • Inspect the ignition setting. If found wrong, you have to adjust it to the correct setting. 
  • Inspect if the throttle cable is sticking. You should consult a mechanic to fix the sticking throttle cable and adjust the ignition setting. 

Problem 4: Engine Backfires

You might notice a loud popping noise, sometimes with a visible noise from the engine when you start the lawn tractor. These are the symptoms of an engine backfiring. 


There can be several reasons behind this problem. For example, broken spark plug, misadjusted carburetor, damaged inlet or outlet valves, wrong valve clearance, and worn-out flywheel key. 


  • Inspect the spark plug and if found broken or damaged, replace it. 
  • Inspect and if required, adjust the carburetor.
  • Inspect the inlet and outlet valves and replace them if they are damaged. The valve clearance should be matched with the recommended number mentioned in the owner’s manual. 
  • While inspecting the valves, check the flywheel key as well. If it is worn out, replace the key. 

Problem 5: Engine Knocks

Unusual knocking sound from the engine while driving the tractor is a common problem that most John Deere LT155 owners face. 


A low engine oil level, contaminated or wrong fuel, faulty cylinder bore or piston rings, clogged cooling fins, and faulty connecting rods are the reasons behind this knocking problem. 


  • Check the engine oil level and if the tank lacks oil, refill it. 
  • Empty the fuel tank every month by draining the old fuel. Refill it with new fuel of the right grade. 
  • Inspect the cylinder bore. If any part is damaged, you have to repair or replace those parts. 
  • Broken piston rings need to be changed. 
  • Access the cooling fin and clean the fins. 
  • Inspect the connecting rod. If found worn out or damaged, replace it. 

John Deere LT155 Electrical Problem

Starter Doesn’t WorkBlown fuse.
Low battery charge.
Corroded terminal. 
Damaged ignition lock.
Faulty wiring.
Faulty Starter.
Replace the fuse.
Recharge the battery.
Clean the terminal.
Replace the ignition lock.
Repair or replace the wiring.
Replace the starter.
Battery Won’t StartLow battery charge.
Dirty or corroded battery terminals.
Dirty cables.
Damaged battery. 
Recharge the battery.
Clean the terminal.
Clean the cables.
Replace the battery.

Problem 1: Starter Doesn’t Work

The most common electrical problem in the John Deere LT155 is the starter stops functioning. 


The most possible reason behind the starter not working is a blown fuse or low battery charge. Corroded terminals, a damaged ignition lock, and faulty wiring can cause this problem as well. In the worst-case scenario, the starter itself might be broken.


First, recharge the battery and see if the starter works. If it doesn’t work, proceed to the next troubleshooting. 

The second method is to inspect the fuse and if it’s blown, you have to replace it. Here’s how you do it. 

  • Step 1: On the John Deere LT155, the fuse box is located under the hood on the right side of the tractor, near the battery. It is hidden behind a panel and secured with a clip. Remove the clip to access the fuse box. 
  • Step 2: The starter fuse is usually labeled as “ST” or “starter”, locate the fuse and inspect if it’s blown. 
  • Step 3: Remove the blown fuse with pliers and replace it with a new one. Make sure to fully insert the new fuse on the socket. 

Then, inspect the starter terminal. If the terminal is corroded, spray some corrosion cleaner and wipe it with a washcloth. Once you are done cleaning, Install the cable in the terminal properly. 

After that, remove the lock cylinder from your JD LT155 dashboard and inspect for damage including break or wear. If required, replace the ignition lock. 

Now, inspect the ignition system wiring. Make sure the connection to the wiring harness is properly installed and the wear doesn’t have any visible wear or tear. If required, replace the wires. 

If nothing of the above works, the starter might be old and broken. Have the starter replaced by a mechanic.  

Problem 2: Battery Won’t Start

Another problem you might have to face as a JD LT155 owner is, the battery may not start from time to time. 


Lack of battery charge, dirty or corroded battery terminals, dirty cables, or a damaged battery can be the reason behind it. 


  • Recharge the battery. 
  • Inspect the battery terminal and cables. If there is corrosion on the terminal, remove them with a corrosion cleaner. Clean the terminal and cables. Reinstall the wiring properly. 
  • If the problem still remains, the battery is damaged and you have to replace it. 

John Deere Lt155 Mower Deck Problem

Problems ReasonsSolutions
Clogged Discharge ChuteGrass is too long.
Grass is wet. 
Driving too fast. 
Improper drive belt tension.
Adjust the cutting height accordingly.
Use the law tractor when the grass is dry.
Drive moderately.
Adjust the drive belt tension.
Belt SlippingDirty sheaves. 
Loosely tensioned belts.
Clean the sheaves. 
Adjust the drive belt tension.
Blades Scalping GrassIncorrect cutting height or wheel height.
Higher blade speed.
Low pressure on the tire.
Bent blade.
Adjust the cutting or wheel height.
Adjust the blade speed.
Inflate the tires.
Replace the blade.
Uncut Grass During OperationClogged cutting deck.
Blunt or damaged blade.
Low deck leveling.
High speed. 
Overfilled grass bagger.
Clean the cutting deck.
Sharpen or replace the blade.
Drive the mower at a moderate speed.
Clean the grass bagger. 
Mower VibratesClogged mower deck.
Clogged sheaves.
Misplaced drive belts.
Imbalance blades.
Clean the mower deck.
Clean the sheaves.
Properly place the drive belt.
Balance the blade.

Problem 1: Clogged Discharge Chute

After a long work on the lawn, a clogged discharge chute can be really frustrating. 


The discharge chute gets clogged usually when the grass is too long or wet or you drive the lawn tractor too fast while cutting. 

Moreover, if you keep the cutting height too much lower than the grass size, it can cause the chute to clog. Improper drive belt tension can cause this problem as well. 


  • Always use the lawn tractor when the grass is dry. 
  • If the grass is too long, adjust the cutting height accordingly. 
  • Don’t drive too fast while cutting the grass. 
  • Check if the driving belt is tensioned properly. If not, adjust the belt tension.

Problem 2: Belt Slipping

It’s hard to drive the lawn tractor properly if the belt keeps slipping. So this problem needs to be addressed as soon as possible. 


Dirty sheaves and loosely tensioned belts are responsible for the problem. 


You have to clean the sheaves or pulleys in the following manner:

Step 1: Remove the spark plug wire to prevent an accident. 

Step 2: Locate the drive belt and remove it to access the sheaves. 

Step 3: Use a small brush or cloth to remove any loose dirt or debris from around the sheaves.

Step 4: If the sheaves are very dirty or covered in grass clippings, you should use a cleaner to remove the buildup. 

Step 5: Rinse the sheaves with water to remove any remaining dirt or cleaner.

Step 6: Let the sheaves dry completely before reinstalling the belt and reattaching the spark plug wire. 

While installing the drive belt, make sure it is adjusted and tensioned properly. 

Problem 3: Blades Scalping Grass

Due to some reason, the JD LT155 can sometimes keep scalping the grass. 


The reasons behind this problem are incorrect cutting height or wheel height, higher blade speed, low pressure on the tire, and bent blades. 


  • Adjust the cutting height according to the grass size. 
  • The rear or front wheel height also needs to be adjusted accordingly. 
  • Check the pressure on all of the tires and inflate them if necessary. 
  • Inspect the blades of your lawn tractor, if they appear to be bent, replace the blades. Here’s how to change blades on John Deere LT155. 

Step 1: Park the tractor and engage the parking brake.

Step 2: Remove the spark plug wire to prevent the engine from starting accidentally. and turn off the fuel valve. use a hydraulic jack to lift the lawn tractor. 

Step 3: Locate the blade under the mower deck. It is held in place by a bolt that passes through the center of the blade and is secured with a nut.

Step 4: Place one or two blocks of wood under the blade so it doesn’t rotate while you unscrew the nut. 

Step 5: Use a socket wrench to remove the bolt and nut that hold the blade in place.

Step 6: Once the bolt and nut are removed, you should be able to lift the blade off of the mower deck.

Step 7: Replace the blade with a new one.

Step 8: Secure the blade in place by inserting the bolt through the center hole and tightening the nut.

Step 9: Reattach the spark plug wire and turn the fuel valve back on.

Problem 4: Uncut Grass During Operation

After covering the whole lawn with your John Deere LT155, you might notice, there is uncut grass here and there. For the same reasons, you may notice uneven cuts on the lawn. 


A clogged cutting deck, blunt or damaged blade, low deck leveling, and high speed can cause this problem. Overfilled grass baggers can cause this problem as well. 


  • Try mowing the lawn at a moderate speed. Don’t drive too fast. 
  • Empty the grass bagger occasionally while mowing the lawn. 
  • Unbolt the deck and take it out to clean it properly. Use a hose to remove all the dirt, debris, and grass clippings from the deck. You can use a scraper to scrape out dirt buildup from the bottom of the deck. 
  • Remove the blade and inspect it. Sharpen the blade with a bench grinder. If the blade is worn out or bent, replace it. 
  • Adjust the height of the deck by raising the wheels. 

Problem 5: Mower Vibrates

While mowing the lawn with your JD LT155 lawn tractor, you may notice the mower is vibrating. 


Clogged mower deck or sheaves, misplaced drive belts, and imbalanced blades can be the reason behind this vibration.  


  • Remove the mower deck and clean it properly. 
  • Remove the drive belt from the sheave and clean the sheave. 
  • Place the drive belt on the sheaves making sure the belt is perfectly aligned and the tension is correct. 
  • Inspect and if required balance the blade. 

Here’s how to balance the blades on a lawn mower

Step 1: Remove the blades from the mower. 

Step 2: Balance the blade in a blade balancer. This tool will allow you to determine which parts of the blade are heavier or lighter than others.

Step 3: If the blade is significantly out of balance, use a grinder or sharpening stone to sharpen the heavier parts of the blade. 

Step 4: Once the blade is balanced, reattach it to the mower. 

This troubleshooting should solve the vibration problem. 

John Deere LT155 Other Problem

Problems ReasonsSolutions
Tractor VibratesWorn out implement or traction drive belts.
Faulty drive sheaves.
Out of balanced blade. 
Bent cutting blades.
Replace the drive belts.
Replace the drive sheaves.
Balance the blade.
Replace the blade.
Tracktor Doesn’t Move With Running EngineLocked parking brake.
Pulled-out bypass valves.
Lack of oil in the transmission. 
Blade is loose.
Balance of the blade is incorrect.
Disengage the brake.
Set the valve to the “off” position.
Refill the transmission oil.
Tighten the blade bolt.
Balance the blade.
Steering ProblemsFaulty pinion gear, bearing, idler, rack gear, or drive belt. 
Clogged air filter.
Replace the faulty part.
Replace the air filter.

Problem 1: The Tractor Vibrates 

Excessive vibration from the lawn tractor or unusual rattling sounds from it can indicate certain problems. 


Worn-out implements or traction drive belts, faulty drive sheaves, and out-of-balanced or bent cutting blades are some reasons behind this problem. 


  • Inspect the implement belt, if you notice any visible wear or tear, replace it. 
  • Inspect the traction drive belt. Replace it if required. 
  • Take out the cutting blade. If the belt is bent, replace it. If found out of balance, fix the balance. 

Symptom 2: Tracktor Doesn’t Move With Running Engine

In this situation, the engine will run when you engage the ignition but the lawn tractor won’t move. 


Locked parking brakes, pulled-out bypass valves, and lack of oil in the transmission can cause this situation. Moreover, it can be a blade issue, for example, the blade is loose or the balance is incorrect. 


  • Make sure you have disengaged the parking brake. 
  • Inspect if the bypass valve is pulled out, and set the valve to the off position. 
  • Check the transmission oil level and if required, refill it. 
  • Remove the blade and inspect the balance. If the blade is off-balanced, fix it. Reattach the blade making sure the bolts are tightened correctly. 

Problem 3: Steering Problems

Common steering problems of John Deere LT155 include not moving left or right, and backward or forward. 


Faulty pinion gear, bearing, idler, rack gear, or drive belt can be the reason behind it. A clogged air filter can cause this problem as well. 


  • Inspect the pinion gear, bearing, idler, rack gear, and drive belt for any visible damage like wearing or breakage. Change the damaged parts. 
  • Check the air filter and if found dirty or clogged, replace it. 

This should solve the steering problem with your lawn tractor. 


Now, you have the complete list of common John Deere LTt155 problems with their solutions. I hope this article will help you resolve this issue immediately whenever you face them. 

Don’t forget to change the filters and oils after every interval recommended by the manufacturer. 

That’s all for now. Have a great day!

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