Differential or transfer case failure on the 2008 Mazda CX-9
When differential or transfer case failure gets reported
Owners of the 2008 Mazda CX-9 report differential or transfer case failure at a median of 110,000 miles. A quarter of the reports come in before 100,000 miles and a quarter after 140,000 miles, from 12 reports that carried an odometer reading.
A part like this is normally expected to survive 110,000 miles. It is the 5th most-reported problem on this model year.
The mileage distribution
The reported range runs from 90,000 miles at the tenth percentile to 160,000 miles at the ninetieth, a spread of 68,700 miles across the middle 80% of reports.
A spread this wide points at use rather than design. Towing, climate, service history and city mileage all move a failure like this, so the median is a weak guide to any individual car.
0% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 90,200 miles | 98,750 miles | 110,500 miles | 139,250 miles | 158,900 miles |
Read the 10th percentile as “one report in ten arrived this early”. Exact figures are shown in this table because it is the table of record; everywhere else on the site they are rounded to the precision the sample can carry.
What a percentile can and cannot tell you here
These five numbers describe the readings owners gave, in order. The median is the middle one: half the reports arrived below it. The 10th and 90th are the edges of the bulk of the distribution, and the distance between them is the part worth reading. A tight spread — say 70,000 to 95,000 miles — points at something that wears out on a schedule, and the schedule is knowable. A wide one, 20,000 to 190,000, points at a fault that hits some cars and never troubles others, which means the mileage on the listing in front of you tells you very little about your odds.
What these figures are not is a survival curve. Every reading here comes from a car whose owner filed a complaint, so the sample contains only failures: it cannot say what share of the fleet made it past 150,000 miles untouched, because those owners had nothing to report. Nor is the mileage the moment of failure — it is the odometer reading as recalled at the time of filing, which may be weeks later and is sometimes rounded to the nearest ten thousand by the person typing it.
Percentiles are shown at all only once 8 readings exist for the vehicle and mode. Below that the middle of a handful of numbers is noise wearing a decimal point, so the figures are withheld rather than dressed up.
What happens, and what it costs
Putting it right typically runs $900–$4,200 at an independent US shop. That range is an editorial estimate held in this site's failure-mode catalogue, not a figure from NHTSA, and it is a repair cost rather than a diagnosis cost.
The same failure on other years
The same failure is reported on 7 model years of this car. It shows up earliest on the 2012, at a median of 55,000 miles, and latest on the 2007 at 135,000 miles.
By volume the 2011 carries the most reports, with 24; the 2008 has 13. A mode that appears across most years of a model is usually a design choice rather than a bad batch.
If one year stands out to the left, that is the year to avoid; if the whole line sits at a similar mileage, this is wear rather than a defect in one production run.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
What owners wrote
Verbatim from NHTSA complaint narratives, trimmed for length. The mileage is the one the owner gave.
Gear oil leaking out of the transfer case vent tube. This is not a normal function. Only way to check level is to remove fill plug and stick finger in. The only safe way to get to this is putting vehicle up on a lift. Researched online and many others are having similar issues. If not caught right away transfer case can fail along with transmission. There is no info on changing this oil at certain intervals. Failure of these two components can happen while driving and could result in injury. I think this should be looked into.
2008 mazda cx-9 grand touring all wheel drive with 20 inch (upgrade) wheels housed in northern va has had a series of suspension system issues. In december 2014 the front driver-side wheel bearing broke while driving from new york to dc. Luckily the roaring sound was noticed and the car was taken to a mr tire in time before the wheel fell off. Front tire wear was also extremely uneven and tires were replaced. Now in summer 2015 a creaking noise while going over bumps and hard turns resulted in the discovery that the front lower ball bearings were loose/had too much play, and we replaced the front lower control arms, swaybar links and bushings, and a broken rear differential mount. Mazda dealer suggests these are normal wear and tear issues. It feels like the suspension system is not designed to manage the weight of the car and normal city/bumpy/pothole driving.
Tl* the contact owns a 2008 mazda cx-9. The contact stated that the vehicle failed to accelerate when the accelerator pedal was depressed. The front driver and passenger wheels spun, but failed to move the vehicle. The vehicle was brought to an independent mechanic who diagnosed that the transfer case needed to be replaced. The vehicle was not repaired.the manufacturer was not notified of the failure. The failure mileage was approximately 92,000.
Also reported on the 2008 Mazda CX-9
Control arm, ball joint or bushing failure
Other suspension problem
Airbag inflator rupture
CV axle or driveshaft failure
Master cylinder or brake booster failure
Other brake problem
How far this goes
Complaints are voluntary, so 13 is a floor and not a count of affected cars. Mileages are typed in by owners and cluster on round numbers. And the mode itself is assigned by software reading the complaint text, which is reliable in bulk and fallible one report at a time.
Questions this page answers
At what mileage does differential or transfer case failure happen on the 2008 Mazda CX-9?
Across 12 owner reports that included an odometer reading, half were filed by 110,000 miles. A quarter were filed before 100,000 miles and a quarter after 140,000 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is differential or transfer case failure on the 2008 Mazda CX-9?
13 reports have been filed with NHTSA, about 0.5 per 1,000 vehicles. Complaints are voluntary, so this is a floor rather than a count of affected cars.
What this is and is not. These are the mileages at which owners chose to complain to a federal agency, which is not the same as the mileage at which the part fails on every car. It skews toward failures that happened outside warranty, cost real money, or frightened someone. It is still the only public dataset that carries failure mileage at all, and the shape of a few hundred readings is informative even when a single one is not. Methodology · JSON · this failure on other cars
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed