Questions re timing belt/seal replacement

#11

"BobN" <nobody (AT) here (DOT) com> wrote

Quote:

"Stephen H" <hansensw (AT) hotmail (DOT) com> wrote

Get the engine to TDC; Subies are real forgiving on the cam drifting when
the belt is removed.

Remove the tensioner and reset it in a vice.
Do all the seals including the crank seal.
Are your valve covers leaking? Also not an imposable job but you will
need to get at them from the bottom.

Thank you, Stephen. That's just what I need. I'd just like to
re-confirm: Once the motor is at TDC I can remove the belt and the
left-side cam sprockets without damaging valves? I have seen the cam lock
tool (although I don't have one), but can't use that if I'm removing the
sprockets to replace cam seals, right?

Once you remove the belt, one cam useally rotates a bit (right one I think)
But just control the speed and only rotate it back, don't go all the way
around. Don't overstress on bending the valves, just remember to break the
crankshaft loose before any belts removed.

You are right IF this is a dual cam motor, then the tool would have to be
removed for the seal change.
Also, if one seal is leaking with 255K miles, then the rubber on all the
rest are just as dry. many times they can be puled out with a just a hook
tool. they are that loose.
ALSO sometimes the pullies stick on. use a good rust penatrate if it dosn't
come free and be carefull on the cam pullies, they can chip or break if
stuck..

--
Stephen W. Hansen
ASE Certified Master Automobile Technician
ASE Automobile Advanced Engine Performance
ASE Undercar Specialist
Currently working at a Subaru Dealership

http://autorepair.about.com/cs/troub...l_obd_main.htm
http://www.troublecodes.net/technical/
http://www.familycar.com/Alignment.htm

Quote:

An article I read in Endwrench suggested the contrary. It's too cold to
commute by motorcycle so I can't risk tying up the car for a week due to
bending valves or breaking anything.

I'll look at all the seals. The valve covers are dry. This is definitely
an issue with the front seals, and I think only the left-side cam seals
are the culprits.

#12

"Stephen H" <hansensw (AT) hotmail (DOT) com> wrote

Quote:

You are right IF this is a dual cam motor, then the tool would have to be
removed for the seal change.
Also, if one seal is leaking with 255K miles, then the rubber on all the
rest are just as dry. many times they can be puled out with a just a hook
tool. they are that loose.
ALSO sometimes the pullies stick on. use a good rust penatrate if it
dosn't come free and be carefull on the cam pullies, they can chip or
break if stuck..

Thanks again. This is the twin-cam motor. I will order the parts tomorrow

and plan to do the job next weekend.

#13

BobN wrote:

Quote:

"Stephen H" <hansensw (AT) hotmail (DOT) com> wrote

Don't know what model is being discussed, but the 2002 WRX manual calls for
a different approach.

Quote:

Get the engine to TDC; Subies are real forgiving on the cam drifting when
the belt is removed.

The WRX can collide valves. I'm sure it's somewhat forgiving, but not like
some of the other subie engines that won't collide anything no matter where
you position things.

Quote:

Remove the tensioner and reset it in a vice.

WRX manual says to do it in a vertical position. Specifically says to
not use a vice. I suspect that applies to all tensioners.

#14

These are good points. I'll ask the Experienced Techs at work tomorrow on
what there opinion is. (These guys do Timing belts and Cylinder head reseals
in under 3 hours)

Steve

"Kurt Krueger" <allez (AT) worldnet (DOT) att.net> wrote

Quote:

BobN wrote:

"Stephen H" <hansensw (AT) hotmail (DOT) com> wrote

Don't know what model is being discussed, but the 2002 WRX manual calls
for
a different approach.

Get the engine to TDC; Subies are real forgiving on the cam drifting when
the belt is removed.

The WRX can collide valves. I'm sure it's somewhat forgiving, but not
like
some of the other subie engines that won't collide anything no matter
where
you position things.

Remove the tensioner and reset it in a vice.

WRX manual says to do it in a vertical position. Specifically says to
not use a vice. I suspect that applies to all tensioners.

#15

">

Quote:

Don't know what model is being discussed, but the 2002 WRX manual calls
for
a different approach.

Get the engine to TDC; Subies are real forgiving on the cam drifting when
the belt is removed.

Quote:

The WRX can collide valves. I'm sure it's somewhat forgiving, but not
like
some of the other subie engines that won't collide anything no matter
where
you position things.

Checked with an experienced tech today on his opinions. Subaru Tech training

says all dual cams can collide valves, Rex says he knows of this but have
never had any problems ever with a bent valve during a timing belt change.
The timing marks on a Subaru are set with the pistons 1/2 way down the cyl,
no chance of piston contact when doing a subie t-belt by the marks.

Quote:

Remove the tensioner and reset it in a vice.

WRX manual says to do it in a vertical position. Specifically says to
not use a vice. I suspect that applies to all tensioners.

Optimally this is the preferred way, but unless you have a special tool for
doing this you will end up in the vice and it will work without any side
effects.

Steve

#16

Stephen H wrote:

Quote:

"

Don't know what model is being discussed, but the 2002 WRX manual calls
for
a different approach.

Get the engine to TDC; Subies are real forgiving on the cam drifting when
the belt is removed.

The WRX can collide valves. I'm sure it's somewhat forgiving, but not
like
some of the other subie engines that won't collide anything no matter
where
you position things.

Checked with an experienced tech today on his opinions. Subaru Tech training
says all dual cams can collide valves, Rex says he knows of this but have
never had any problems ever with a bent valve during a timing belt change.
The timing marks on a Subaru are set with the pistons 1/2 way down the cyl,
no chance of piston contact when doing a subie t-belt by the marks.

Remove the tensioner and reset it in a vice.

WRX manual says to do it in a vertical position. Specifically says to
not use a vice. I suspect that applies to all tensioners.

Optimally this is the preferred way, but unless you have a special tool for
doing this you will end up in the vice and it will work without any side
effects.

Steve

But you must compress the tensioner VERY slowly and incrementally over
several minutes IIRC.

And personally, I would change the tensioner bearing and other
rotating/sealing components while I was in there as is typically
recommended to be thorough.

Carl

--
to reply, change ( .not) to ( .net)

#17

Quote:

Checked with an experienced tech today on his opinions. Subaru Tech training
says all dual cams can collide valves, Rex says he knows of this but have
never had any problems ever with a bent valve during a timing belt change.
The timing marks on a Subaru are set with the pistons 1/2 way down the cyl,
no chance of piston contact when doing a subie t-belt by the marks.

On the driver's side of the DOHC engine, the cams
are "balancing" on their lobe points and want to
release tension and rotate around. When you
rotate them back to the alignment marks, you can
either turn them a "short way" (maybe 90* or so)
or the "long way" (270* or so). The information
I've seen warned to NOT rotate them the "long
way", to prevent valve damage.

Quote:

Remove the tensioner and reset it in a vice.

WRX manual says to do it in a vertical position. Specifically says to
not use a vice. I suspect that applies to all tensioners.

Optimally this is the preferred way, but unless you have a special tool for
doing this you will end up in the vice and it will work without any side
effects.

The FSM and Endwrench stuff is pretty picky about
compression--only in a vertical plane, slowly,
etc. I used a vice to hold the tensioner body
and compressed the plunger with a C clamp...easy
enough.

#18

Compressing the tensioner sideways as not recommended and can
introduce air. The air may not cause problems until thousands of miles
later. Subaru factory is adamant about using only vertical compression
and at a max force of ~50 lbs. Foolish to outguess the factory on this
critical component with so much at stake. JMO Ed
"CompUser" <NoooSpamm (AT) yahoo (DOT) com> wrote

Quote:

Checked with an experienced tech today on his opinions. Subaru Tech
training
says all dual cams can collide valves, Rex says he knows of this
but have
never had any problems ever with a bent valve during a timing belt
change.
The timing marks on a Subaru are set with the pistons 1/2 way down
the cyl,
no chance of piston contact when doing a subie t-belt by the marks.

On the driver's side of the DOHC engine, the cams
are "balancing" on their lobe points and want to
release tension and rotate around. When you
rotate them back to the alignment marks, you can
either turn them a "short way" (maybe 90* or so)
or the "long way" (270* or so). The information
I've seen warned to NOT rotate them the "long
way", to prevent valve damage.

Remove the tensioner and reset it in a vice.

WRX manual says to do it in a vertical position. Specifically
says to
not use a vice. I suspect that applies to all tensioners.

Optimally this is the preferred way, but unless you have a special
tool for
doing this you will end up in the vice and it will work without any
side
effects.

The FSM and Endwrench stuff is pretty picky about
compression--only in a vertical plane, slowly,
etc. I used a vice to hold the tensioner body
and compressed the plunger with a C clamp...easy
enough.

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Questions re timing belt/seal replacement

Subaru Subaru vehicles (alt.autos.subaru)

Re: Questions re timing belt/seal replacement - 12-10-2006 , 12:53 AM

Re: Questions re timing belt/seal replacement - 12-10-2006 , 09:05 AM

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Re: Questions re timing belt/seal replacement - 12-11-2006 , 01:37 AM

Re: Questions re timing belt/seal replacement - 12-11-2006 , 11:44 PM

Re: Questions re timing belt/seal replacement - 12-12-2006 , 07:29 AM

Re: Questions re timing belt/seal replacement - 12-12-2006 , 09:58 AM

Re: Questions re timing belt/seal replacement - 12-12-2006 , 11:10 AM