2003 Legacy Outback H6 3.0 VDC Wagon

[anthonmas]

I just brought a Subaru Legacy Outback H6 3.0 VDC Wagon. Since this is my first Subaru does the car require any special maintenance?

 

Thanks:-)

[alias20035]

Follow the maintainance schedule provided with your vehicle...

 

Subaru's don't really require any special attention, although I will make the following points:

 

Every 2 years or 30000 miles do ALL of the following:

 

1. change the coolant

 

why: coolant becomes corrosive which is extremely bad for aluminum engines and radiators (both on your Subaru). Changing the coolant per the schedule means that you generally don't have to use a cooling system flush which is extremely corrosive and must be flushed out of aluminum engines and rads within 10 minutes to avoid serious damage. Improper use of coolant flush can lead to radiator leaks and blown head gaskets.

 

2. change the front and rear diff fliud

 

why: Subaru diffs work hard, and also tend to collect water. Your VDC does not have a viscous locking rear diff, so it does not work the fluid as hard. But its only $3 of fluid ($7 if synthetic). The front diff is within the transmission case and is thus subject to higher than normal temperatures compared to other vehicles.

 

3. change the Automatic transmission fluid and filter

 

why: the ATF fluid in Subaru's is used both for the transmission and AWD transfer clutch, which can lead to higher temperatures than all other cars. Subaru's since 1999 have a spin off ATF fluid filter (like an oil filter) and a drain plug. Pulling the transmission pan to change the fluid is not required. Be sure to flush the old fluid out of the transmission cooler which is built into the lower section of the radiator.

 

4. change the brake fluid

 

why: Brake fluid absorbs water, and when a certain amount of water is present in the system, rust will occur. The ABS system and in your case the VDC system can rust out as well as the brake calipers. Rust will kill the ABS pump and seize calipers.

 

All of the above is pretty much standard for all cars now, although some cars now have long life coolant (7yr/100000mile I believe), and others have sealed transmissions that do not required ATF changes (they don't even have a dipstick).

 

Subaru's just work the fluids a little harder than other cars...

 

Subaru recommends lubricating the wheel bearings at 60,000 miles and I am not sure why. Wheel bearings are a common point of failure on Subaru's, especially rear bearings, and those on Forester's and Impreza's. I am fairly certain that relubricating the bearing is only a few steps short of replacing one (maybe only 10 minutes more work to replace), so why bother, just wait for the bearing to start whining or rumbling (usually the rears will fail at 75-120,000 miles, and the fronts will last longer).

 

Someone correct me on the bearing lubrication issue if there is in fact a quick method of relubrication.

 

The only other issue I can think of is fuel octane requirements. The H6-3.0 can use 87 octane, but 91 is recommended (my 2001 manual indicates that the H6 requires 91 octane, but I am fairly certain that Subaru retuned the H6 for 87 octane in MY2002, see your manual for more information).

 

I would stick to 91 octane in summer, and use 87 octane in winter. Why? Lower air intake temperatures and lower engine temperatures mean less chance of detonation (ping), which should mean that lower octane fuel can be used.

 

My H4-2.5 Outback only requires 87 octane fuel, but I find that I get too much detonation (ping) and loss of power on hot days, so I use 89 octane in summer.

 

You may find that 91 octane works in summer, 89 in spring/fall and 87 in winter. A friend of mine in Calgary, Canada runs 91 octane from mid June to mid September and 87 octane the rest of the year, and notes no ping whatsoever.

[anthonmas]

alias20035,

 

Thanks for your reply. I will make a note of your reply and follow through when the time comes.

 

:-)

[alias20035]

Originally posted by anthonmas

alias20035,

 

Thanks for your reply. I will make a note of your reply and follow through when the time comes.

 

:-)

 

I did forget the most important item.

 

TIRES

 

Subaru (and all other AWD) vehicles require the owners to be extremely careful with regards to tires.

 

It is absolutely essential that all four tires be exactly the same design and circumference. Any difference on one tire will destroy the AWD system in short order. Tire problems are the number one cause of differential, wheel bearing and transmission (AWD section) failures on Subaru's.

 

I was told by a Subaru Canada technical rep that a 1 or 2 inch circumference difference will not harm the AWD system. In terms of percentages, the Outback tire diameter is about 27 inches (0.394inches/cm*(2*(22.5cm*60%))+16 inches = 26.638 inches in diameter. 26.64*3.14 = 83.65 inches in circumference. So a 1 inch circumference difference is only a 1.2% size difference. Subaru's AWD system does very little work until the axle speeds differ by 10% or even 20%. But keep in mind that a 1.2% difference between tires on one axle is divided by 2 (because of the differential) and then multiplied by the axle ratio (4.11), so 1.2% becomes 2.47% to the VTD clutch or viscous coupling

 

Here are the general rules you should follow with your Subaru (and I would say apply to all other cars as well).

 

1. Check your tire pressure often (at least every two weeks). Recommended tire pressure is listed on a tag on the drivers door B pillar (should indicate 30 PSI front/29 PSI rear or 30PSI all around)

 

Don't forget to check your spare tire (60 PSI), mine looses 5 PSI each month!!!

 

With seasonal temperature changes the tire pressure will change, you will need to add air to tires in winter, and release air in summer.

 

ALWAYS check tire pressures cold (best time is if the car has not been driven in 3 or more hours).

 

2. rotate the tires every 6,000 miles. Subaru's wear the rear tires a little quicker than the fronts, so it is important to balance out the treadwear by regular rotations. I recommend rotating the tires front to rear and not switching sides.

 

3. before getting into the car to drive off, walk around the car and look for signs of low tire pressure. My sister destroyed a tire and alloy wheel by driving 500 feet on a flat tire, and the wheel bearing failed shortly thereafter (replaced under warrenty with only 8,000 miles on the car).

 

4. If a single tire is damaged beyond repair and has to be replaced, an identical model and size must be used. Also the circumference of the tires must be checked and the new tire must be no more than 1.5 inch (one and a half inches) larger in circuference. If the damaged tire has more than 30,000 miles on it, it is likely that you will need to replace all four tires.

 

NEVER EVER plug a nail hole in a tire, have the tire removed from the wheel and install a patch inside. The insertion of the pulg does further damage and can lead to blow outs.

 

5. Snow chains can not be used on the Outback, and this is noted in small print in the tires section of the owners manual. The snow chains will not fit between the front tire and front strut, leading to mechanical and tire damage. Since snow chains are mandatory on some roads (mountain roads) your only option would be to install a good set of snow tires. Most newer snow tires have a snowflake/mountain logo printed on them which indicates that they are suitable for extreme snow and ice conditions. Tires with this snowflake/mountain logo are EXEMPT from the snow chains requirement in all of Canada and most US States including Colorado, Utah, Washington, California, New Mexico, Nevada, Oregon, Idaho, Montana, and Wyoming.

 

Transport Canada information on the Snowflake/ Mountain logo

[Guest lothar34]

Make sure you read the part in the owner's manual about towing too.

[mtsmiths]

"Stealership"