AWD and driving on a spare

[Hentai]

We put about 30 miles on my 97 Subaru Outback Legacy after blowing the tire and putting on the doughnut spare. I had to order a tire and it will be installed on Friday.

The problem I am having is that there is a gear or joint "clanking" usually a bit more when I go around corners.

Will it go away with once the new tire is installed?

 

I have heard that the gear ratios and what not can get screwed up with different sized tires on an AWD car.

Any ideas?

Hentai

[Guest lothar34]

Do you still have your owner's manual?

Manual transmission or auto?

[Setright]

That spare tyre comes with the car right? So it probably has the same diameter as standard wheels - have you fitted bigger rims and increased the overall wheel diameter?

[charlierh2]

did you put in your fwd fuse like it says in the manual?

[Commuter]

It's a donut spare. (At least it is in my 97 OB Auto.)

 

The odds are that you have an Automatic. In this case, the donut spare is to go on the back and the all important fuse is to be put into the FWD holder under the hood near the passenger side strut tower. This puts the car into FWD mode, thereby ensuring that you don't fry your center differential (clutch pack). It doesn't take much to do damage to it! And they are a little fragile on this particular year (I forget the exact detail) usually failing in the order of 120k miles.

 

If you have a manual transmission, then you can drive on the donut spare for a brief time. The VC (viscous coupling) center differential can only take so much though.

 

In either case, get the full sized tire fixed and back on the car ASAP. If you need a different tire, it must match other other 3 to within 1/4" on the circumference. Oops... I see that you said you had to order a tire. I hope it matches. With my current set of tires, I had to replace one after a relatively short time. Even at that, there was already close to 1/4" difference. Note that 1/4" on the circumference is only 1 mm (millimeter) difference in tread depth! (Sorry for mixed units, but it just works out nicely that way.) I jacked my car up and wrapped a tape measure around the tires to check before I pulled the fuse back out.

 

Commuter

[SevenSisters]

It would have been too simple for Subaru to make the spare the same size.

 

Pull the fuse and buy a full size spare.

[Ranger83]

If you need a different tire, it must match other other 3 to within 1/4" on the circumference. Oops... I see that you said you had to order a tire. I hope it matches. With my current set of tires, I had to replace one after a relatively short time. Even at that, there was already close to 1/4" difference. Note that 1/4" on the circumference is only 1 mm (millimeter) difference in tread depth! (Sorry for mixed units, but it just works out nicely that way.) I jacked my car up and wrapped a tape measure around the tires to check before I pulled the fuse back out.

Some tire shops can mill a tire to a smaller diameter. It's regularly done for competition tires. But unless your tires are very worn I'd put the new one on the front right and be happy.

[Hentai]

GAAAAwwwwww Dam

Shoulda came here first!

 

I didnt look at the owners manual when I changed the tire... never thought I needed to!! Now I know.

 

I didnt drive it anymore after I noticed the noises. Now that the original size tire (which I'm not sure will be close enough to the other 3 tires, although they are in good shape) there is almost no noise. Only occationally when I go around corners (yes I am a bit nervous still) I am going to check the manual tomorrow and see if I can get it to work in 2 FWD mode and see if it is still ocationally making noise due to the size of the new tire... if not I am going to be sad and have dirty hands.

Tsuriman