2008 Harley-Davidson Flhtcu Problems

What owners report

Owners of this model year most often describe brake problems, particularly the anti-lock brake module leaving the front or rear brake lever or pedal stuck and unusable with no warning light. A second cluster of complaints covers electronic throttle behavior, high or unsteady idle, unresponsive throttle, and sudden power loss, along with compensator noise and vibration on the primary drive side.

1. 1
   Brakes

   ABS module failure leaves brake lever or pedal frozen

   • 24 complaints (30%)
   • median 36,584 mi at 9.2 yrs old (21 state mileage)
   • 4 mention a crash, fire or injury
   • filed 2007–2022

   Riders describe applying the front brake lever or rear pedal and finding it locked solid or sunk with no braking effect, often with no ABS warning light showing. Several say one brake still worked well enough to slow down, while others describe the motorcycle rolling through an intersection or needing a tow. According to the complaints, dealers typically diagnosed a failed ABS module and ordered a replacement; some owners were told the module was obsolete and hard to source, and a few report brake trouble continuing after the recall service was performed. Reported from under 10,000 miles up past 70,000, most often between roughly 10,000 and 50,000 miles, during ordinary stops in traffic or on city streets.

   Recall 18V076000

   What to check: Ask whether recall 18V076000 was completed and whether the ABS module has been replaced since. Before buying, test both brakes at low speed and confirm the ABS lamp behaves normally at startup.

   2 excerpts from owner complaints in NHTSA records

   “While attempting to come to a stop at a traffic signal the rear brake locked up with no warning. Luckily I was going straight and was able to recover the skidding bike before I hit the car ahead of me. I brought my bike the local dealer and the claim the ABS module is bad.no one mentioned to me about the recall.”

   NHTSA complaint #11071740, filed 2018-02, 9,200 miles

   “While riding my 2008 Flhtcu at low speeds my front break lever became frozen in place, the lever would not engage the brakes at all. The bike did not display any fault codes. I took the bike to my local dealership and they verified my ABS module had failed and needed replaced. My complaint is, the bike was in good mechanical condition and with out warning I had a catastrophic break failure. …”

   NHTSA complaint #10564630, filed 2014-02, 21,000 miles
2. 2
   Fuel system

   Unsteady idle and unresponsive throttle

   • 12 complaints (15%)
   • median 14,300 mi at 4.5 yrs old (12 state mileage)
   • 1 mention a crash, fire or injury
   • filed 2008–2018

   Owners describe the electronic throttle holding a high idle after startup, lurching or failing to hold steady speed, and in some cases the engine losing power or stalling while riding. Complaints mention the throttle going unresponsive on restart, requiring a shutdown and restart to move again. Dealers reportedly cleaned or lubricated throttle connections, replaced wiring harness pins or the throttle assembly, and in one case advised that a repair might not be a permanent remedy. Reported from near-new mileage up to around 35,000 miles, often noticed at startup or at steady cruising speed.

   Recall 08V357000

   What to check: Ride the bike from a cold start and watch whether idle settles consistently; ask if the throttle wiring, throttle body, or ECM has been replaced, and whether any stored codes were read.

   2 excerpts from owner complaints in NHTSA records

   “I own a 2008 harley davidson flhtcui. I have had it in the shop three times because of this same problem. It has an electronic throttle. It will only idle. Right now. It has been in the shop for 3 weeks and the dealer claims they cannot get the needed part for another 3 weeks. It is an upgraded part. I feel a recall is warranted. It did this when I was going down the road.”

   NHTSA complaint #10406003, filed 2011-06, 14,100 miles

   “1. Sudden throttle lost control, get to shoulder, turned bike off and started. Randomly happened. 2. Last year I replace ecu - it's ok over a year and now it happened again. 3. I search in internet - many owner have same issues and don't know how to fix. The dealer service charge me a lot of money and they could not figure out since when it's in the shop the bike seem to be ok. Now the issue seem to happen more often 4. Code p1511 and p2135”

   NHTSA complaint #11055067, filed 2017-12, 20,000 miles
3. 3
   Engine

   Compensator sprocket wear and primary drive noise

   • 9 complaints (11%)
   • median 20,000 mi at 5.2 yrs old (9 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 2010–2017

   Complaints describe loud clanking or rattling from the primary side, vibration and skidding under acceleration, and in some cases difficulty starting. Owners who had it inspected say the compensator sprocket or clutch assembly splines were worn or damaged and were replaced with an upgraded assembly. Several report the dealer called the noise normal until it failed, and that the repair was at owner expense. Most often reported between roughly 13,000 and 35,000 miles, sometimes earlier, and often noticed under hard acceleration or at highway speeds.

   What to check: Listen for clanking or rattling from the left primary cover at idle and under acceleration, and ask whether the compensator has been replaced with the upgraded part.

   2 excerpts from owner complaints in NHTSA records

   “Stock compensator on 2008 ultra classic failed and now have to pay for replacement to put the upgraded one in. Lucky I was not traveling at highway speeds or I would have been killed. Harley is aware there is a problem and refuse to fix the problem. The stock compensator is inferior to the upgrade and harley now puts the upgrade stock on the 2011 bikes. I feel this should be replaced at not cost since it is a safety issue.”

   NHTSA complaint #10404131, filed 2011-06, 15,000 miles

   “In april 2012 I was experiencing loud noises from the primary side of my 96 v twin engine and it would not start. Upon inspection by a certified harley tech. It was discovered the entire clutch assembly and compensator sprocket were damaged due to the disintegration of the splines and gears. As advised by harley davidson, their supplier shipped these parts without heat treating them . I was never advised this was a problem by harley. …”

   NHTSA complaint #10681818, filed 2015-02, 29,985 miles
4. 4
   Transmission and drivetrain

   Front-end and rear-wheel wobble while riding

   • 5 complaints (6%)
   • median 26,000 mi at 4.7 yrs old (5 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 2008–2015

   Riders describe the front end or rear wheel wobbling or feeling like it shifts sideways in curves, sometimes starting at highway speeds and worsening over time. Some complaints trace it to a failed wheel bearing, while others say repeated dealer visits and suspension adjustments did not resolve it. Owners mention spending money on steering and suspension work without a lasting fix. Reported from a few hundred miles up to about 38,000 miles, typically at highway speeds or while cornering.

   What to check: Test ride at highway speed and through curves, check for play or noise in the wheel bearings, and ask about the condition of the steering head bearings and rear swingarm mounts.

   2 excerpts from owner complaints in NHTSA records

   “I have a 2008 harley davidson ultra classic that has developed a rear wheel wobble while cornering or going through curves. The vehicle feels like the rear wheel slides or shifts to the side while cornering upsetting the balance of the bike and making it uncomfortable/dangerous to ride. It has progressively gotten worse and I will no longer ride the motorcycle. I've had the motorcycle into the dealer at least 3 times for the problem. The first two times they advised me they couldn't find a problem. …”

   NHTSA complaint #10509712, filed 2013-04, 38,000 miles

   “There is a speed wobble starting in the 60's and continuing through the 70's+ on straight roads and curves. This has been happening for years and I still continue to spend money adjusting etc. The bike I've spent thousands in labor and parts to fix and or adjust the bike without success. I've called harley davidson more than once to be told that they are not aware of an issue and I'm on my own because it is out of warranty. I've researched the internet to find dozens of news and private complaints to the problem. …”

   NHTSA complaint #10790297, filed 2015-11, 26,000 miles
5. 5
   Brakes

   Rear brake line worn through by clutch cable

   Mentioned in 4 of 60 sampled complaints

   Complaints describe the rear brake fading or failing completely and finding brake fluid leaking, traced to the clutch cable rubbing against the rear brake line until it wore a hole. Owners report the loss happened during normal riding, with the front brake used to stop. One complaint notes the steel line had been sanded through where the two parts are routed together. Reported from around 9,000 to 64,000 miles, with no single clear mileage window.

   What to check: Inspect the rear brake line where the clutch cable crosses it near the engine for chafing, flattening, or fluid residue, and check the rear reservoir level.

   2 excerpts from owner complaints in NHTSA records

   “I was operating my 2008 harley davidson Flhtcu when I applied my rear breaks only to find I had no rear breaks. I still had my front breaks that worked very well. I have 9,600 miles on the motrocycle. I took my motorcycle to the harley dealer and asked the service writer to check my rear breaks as I told him there were no breaks. …”

   NHTSA complaint #10421627, filed 2011-08, 9,600 miles

   “While coming to a slow stop using both front and rear brakes the foot pedal for the rear brakes felt soft and went down to the floor board. Upon stopping the motorcycle I noticed brake fluid dripping from under the motor. During examination I saw that the rear brake line was leaking at the point where the clutch cable crosses between the motor and the line. The vibration of the motor apparently caused the clutch cable to wear a hole in the rear brake line due to the routing of the two parts.”

   NHTSA complaint #10595223, filed 2014-05, 45,546 miles

Buying note. Brake complaints dominate this model year, so confirm the ABS recall was performed and budget for a module replacement if it has not been. A cold-start test ride, a look at the primary drive for noise, and a check of both brake circuits will cover most of what owners describe.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.