RoadVitals

2018 Harley-Davidson Flhr Problems

Owner-reported complaints filed with NHTSA, grouped by component

Data refreshed

Owner complaintsComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
5
Latest Jul 12, 2026
Components namedHow many of our component categories appear on at least one report for this model year. One report can name several.
2
Crash or fire reportedComplaints whose submitter recorded that a crash or a fire occurred. These are the reporter's own answers on the NHTSA form, not verified findings.
0

What this page shows

Everything below is an owner-reported complaint submitted to NHTSA about the 2018 Harley-Davidson Flhr, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.

Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.

Reports by component

Ranked by how many owner reports name each component category

  • Powertrain (other)360.0%
  • Engine240.0%

Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.

Each component in detail

What the reports in each category say, in the owners' own words

Powertrain (other)

Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.

3
reports

From owner reports, verbatim

The contact owns a 2018 Harley-Davidson FLHR Road King. The contact stated that upon start of the motorcycle there was an abnormal grinding sound coming from the motorcycle without warning. The contact had taken the motorcycle to a dealer where he was informed that the gears inside of the transmission were breaking apart and that the transmission needed to be replaced. The dealer was able to order a new transmission and replaced the transmission under warranty; however, despite the repair, the failure returned and the contact returned the motorcycle back to the dealer. The contact had attempted to reach the manufacturer on numerous occasions but was unsuccessful after each attempt. The motorcycle had not been repaired and remained in the possession of the dealer. The failure mileage was approximately 6,100.

NHTSA ID 11460871 · filed Apr 15, 2022

THIS IS A DESCRIPTION OF THE DRIVABILITY PROBLEMS CAUSED BY THE EXCESSIVE PRIMARY CASE FLUID. WHILE IN MOTION ON A CITY STREET THE MOTORCYCLE WOULD SOMETIMES NOT SHIFT DOWN FROM 3RD-2ND OR FROM 2ND TO 1ST GEARS. THIS CAUSES PROBLEMS WHEN TURNING AND WANTING TO USE ENGINE BREAKING TO SLOW DOWN DURING THE TURN. I COULD NOT USE THE ENGINE BREAKING AND WOULD HAVE TO USE THE BRAKES QUICKLY AS TO NOT CAUSE AN ACCIDENT. ALSO, WHEN SITTING STILL WITH ENGINE RUNNING IN NEUTRAL AT A TRAFFIC LIGHT, THE TRANSMISSION WOULD SOMETIMES NOT SHIFT FROM NEUTRAL TO 1ST GEAR. THE DELAY IN TRYING TO PROCEED CAUSES OTHER MOTORISTS TO ALMOST RUN INTO THE BACK OF MY MOTORCYCLE. THIS WAS MOST DANGEROUS WHEN TRAVELING IN A GROUP OF MOTORCYCLES RIDING CLOSE TOGETHER. ALSO, DURING AN EMERGENCY STOP CONDITION WHEN TRAVELING ON A CITY STREET ABOUT 50 MPH IN 5TH GEAR, IT IS VERY DIFFICULT GET OUT OF THE WAY FROM CARS OR TRUCKS BEHIND ME. THIS IS BECAUSE YOU MUST BE IN A LOWER GEAR THAN 3RD TO GET OUT OF THE WAY ONCE YOU HAVE COME CLOSE TO STOPPING. MOTORCYCLES CAN STOP MUCH QUICKER THAN CARS OR TRUCKS. IF I CAN'T GET OUT OF THE WAY, I COULD BE INJURED OR KILLED. HARLEY-DAVIDSON TRIED TO FIX THIS ISSUE IN OCT '19. UNDER WARRANTY THEY ADDED A BREATHER KIT PART# 26500027. MY DRIVABILITY ISSUES STARTED ABOUT 6,000 MILES AFTER HARLEY-DAVIDSON SAID IT WAS FIXED. AFTER DRIVING ABOUT 6,000 MILES THE DRIVABILITY PROBLEMS STARTED. AT THAT TIME, I CHANGED THE PRIMARY FLUID AND FOUND 7 EXTRA OUNCES OF OIL. WHEN PUTTING IN THE CORRECT 30 OUNCES OF FLUID THE DRIVABILITY ISSUES STOPPED. SEE ATTACHED TA0022 HARLEY-DAVIDSON KNOWS THE ISSUE. # DEAD? THIS IS FROM PAGE 149 OF MY HARLEY-DAVIDSON OWNER'S MANUAL. NOTICE: DO NOT OVERFILL THE PRIMARY CHAINCASE WITH LUBRICANT. OVERFILLING CAN CAUSE ROUGH CLUTCH ENGAGEMENT, INCOMPLETE DISENGAGEMENT, CLUTCH DRAG AND/OR DIFFICULTY IN FINDING NEUTRAL AT ENGINE IDLE. *TR

NHTSA ID 11329656 · filed Jun 18, 2020

Too few reports in this category for a page of its own — they appear in the full complaint list.

Engine

Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.

2
reports

From owner reports, verbatim

I have oil in my breather which is a result from engine sumping problems, I have had Harley Davidson to check recalls and there were none., the bike has 22853 miles on it. Also Harley Davidson checked maintenance records to see if my oil pump had been replaced, they said it had not. The sumping problems could cause a catastrophic failure and an accident

NHTSA ID 11749847 · filed Jul 12, 2026

ENGINE GETS HOT AND STALLS OUT IN TRAFFIC DUE TO ENGINE CASE FILLING WITH OIL, HARLEY CALLS THIS WET SUMPING, HUNDREDS OF BIKE ENGINES ARE BLOWING UP ALL OVER THE WORLD, ITS ALL OVER THE INTERNET, WITH HARLEYS NEW M8 ENGINE, THE BIKE STALLS OUT WITH NO WARNING, IVE HAD CARS AND TRUCKS ALMOST RUN ME OVER.

NHTSA ID 11097743 · filed May 24, 2018

Too few reports in this category for a page of its own — they appear in the full complaint list.

Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.

Elsewhere on this vehicle

Data sources

Data on this page last refreshed .