Brake band adjustment!
 

The brake band adjustment is one of the most important procedures that an owner can perform.

This is how I do it.
Open (and prop if necessary) the hood.
Disconnect the battery negative.
Remove the throttle body H-6 cover (two phillips screws).
Remove the airbox, three hose clamps and five small vacuum hoses, and one three inch at the air filter.
http://www.subaru-svx.net/photos/fil...iles/25157.jpg
The easiest way I have found to get to the adjustment, is to lay on the engine, with your chest on the intake manifold.
If you have a (flourescent) light you can see the adjustment screw (8mm square) poking up through the 17mm locknut.
http://www.subaru-svx.net/photos/fil...iles/25158.jpg
This gives you an idea of the location.
http://www.subaru-svx.net/photos/fil...iles/25183.jpg It is still hard to see, but the wrench is on the lock nut.
http://www.subaru-svx.net/photos/fil...iles/25185.jpg
If you use a Sears Craftsman 17/19 mm box wrench that's 11.25" long, it will slip under the wiring loom, and on top of the starter.
This wrench has the correct angle, and it is long enough to give sufficient leverage.
http://www.subaru-svx.net/photos/fil...iles/25192.jpg
Sears also sells a Companion 8 mm open end/box end wrench that is 5.5" long, making it a good choice for the actual adjustment.
To tighten the band (to compensate for wear), turn the adjustment screw clockwise.
The Subaru service manual says to tighten it to 6.5 foot pounds, and then unscrew it three turns. Then tighten the lock nut to 18-21 foot pounds.
In my opinion this adjustment is too loose.
But this is what the book says.
When I tighten mine it is only until I can feel a slight drag, and then I tighten the lock nut.
Some other members use the factory torque specs and then only back off TWO turns.
With the correct wrenches, and some practice, this job becomes easier.

Here are the specs from the manual:
http://www.subaru-svx.net/photos/fil...iles/25222.jpg

Nice write-up with pics Tom! :)

-Chike

I would note that on my 98 Imprezza tranny the adjuster is a 8mm hex head. On the OEM SVX box (92 MY) the adjuster was a 7mm square head. Not sure how much bearing this has (does the 8mm box fit a 7mm square?), but thought I'd point it out.

I would also note that the Automatic Transmission Service guide (for Imprezza/Legacy models) specifies a two turn arrangement while the SVX calls for 3 - I have still not found anyone with an Imprezza FSM to confirm.

otherwise spot on and correct - good job.

and if you want to lose Reverse, tighten that puppy down real good!:rolleyes: :rolleyes: :p
-Bill

Band adjustment, how much?
 

Just to explain what the adjustment does.

In first gear the forward clutch is on, to change to 2nd, the band is applied, no problem. To get 3rd, the band is released, and the high clutch is applied. If the band is too loose, the band will release before the high clutch locks-up. This causes the flar in the rpms till the clutch locks-up for 3rd.

If the adjustment is too tight, the band will be too slow to release, and will still be applied when the high clutch locks-up. This will cause the box to bind till the band does release.

The timing between the two actions, band off, high clutch on, is controlled by the one servo action. The same pressure releases the band and applies the clutch. This is why the amount the adjustment is backed off, sets the timing between the two actions. Too tight, it binds, too loose it flars.

Harvey.;)

Re: Band adjustment, how much?
 

Thanks Tom and Harvey,

My band definately needs tightening. Does anyone know why some specs call for two turns and SVX specs call for three turns?

Checked our 4.44 Outback trans from wrecker, it was exactly two turns.

I know what flar feels like, bind sounds worse!

Harvey, like i told you in my PM i get that braking feeling sometimes between the 2-3 shift. Doesnt happen all the time but it does happen. How could the band be getting too tight over time? Ive driven it like this since june of 04 with no change.

Great write up! I actually did mine last week and took pictures with the intent of writing a how-to but you saved me all the work! :D

Thanks.:) One and all.

Most excellent... I think this should be filed under FAQ's and How To's. Yeah, that good.

Thanks for the pictures too! I would like to do this, but seems like it could be a real pain in the @$$. The pics help.

Re: Re: Band adjustment, how much?
 

Hi Ron, the number of turns, affect the timing of the two gears. Don't know why the two different boxs have different amounts. Could be a difference in construction, or a difference in the TCU timing.

The flar and binding is not a damaging event. The flare is caused by the band releasing before the high clutch engauges. This is not wearing the band it is just that, as the box goes to change from 2nd to 3rd, in goes back to 1st. It can't over rev the engine as there is a freewheel clutch in there to prevent it, so the engine just free reves, till the clutch locks-up.

With the binding. If the band does not release as the high clutch engauges, the two are on together, so the box goes into 4th gear, till the band releases to give 3rd.

The other case is when the box is in 4th, and slips back to 3rd, then back to 4th. This is the band slipping and wearing. When this happends, the band needs to be adjusted quickly, or it will be damanged and you will loose 4th and 2nd. Till it is done you should not use D position, just keep it in 3rd to prevent it from burning the band up.

Harvey.;)

Can't say for sure, may be it isn't getting tighter, just on the tight side and other things are affecting the rate that it is released.
This action is a mechanical/hydraulic event, and can be affected by temp, pressure and the mechanical action itself. But it should not be that senseritive to other things if it had the right clearance.

This is why the later boxs use a ECU solenoid operated clutch brake, instead of the band brake, to avoid the timing problems.

Harvey. ;)

Band adjustment, how much?
 

Thanks Harvey,

This info is appreciated by all.

Harvey is our certified tranny master :)

I'd love to do this to my car, but I've got a couple questions... How do you know that you've reached the specified torque setting, so that you can back off the required amount? I mean, you have a hard enough time even getting a couple of small wrenches in there, so how could it be any of an improvement if you don't even know what you're doing is precise?