resurfacing flywheel?

I've got a question about resurfacing (machining) the flywheel
when I replace the clutch (disk, throwout bearing, and pressure place)
on a 1987 Toyota Tercel, 3E engine, 4 speed manual xmission, 150k miles.

I've actually got the official Toyota service manual for this car, which
details all the repair procedures. The manual seems quite thorough,
however... the section regarding replacing the clutch says nothing
about machining the flywheel. Instead, it says to REPLACE it
"if necessary".

The Haynes and Chilton manuals do say the flywheel should be
resurfaced. But... they don't say what the minimum flywheel
thickness is?!

Q#1: should I machine the flywheel when I replace the clutch, or
just use some 80 grit sandpaper (by hand)?


Q#2: what's the minimum flywheel thickness?
The Toyota Service Manual doesn't specify a min. thickness for
the flywheel (nor do the Haynes or Chilton manuals).

That seems very odd -- I would've thought that the flywheel
would have a minimum thickness (just like brake rotors).

Thanks in advance,
-Ted

[email]ted@estaff05.mayfield.hp.com[/email] (Ted Johnson) wrote in
news:e3oiok$a3r@estaff05.mayfield.hp.com:

[color=blue]
>
> Q#1: should I machine the flywheel when I replace the clutch, or
> just use some 80 grit sandpaper (by hand)?[/color]




Don't sand it. Get it machined. The machine shop will know what to do. You
need that surface flat and true, not roughened. Machining is cheap, less
than $50.

[color=blue]
>
>
> Q#2: what's the minimum flywheel thickness?
> The Toyota Service Manual doesn't specify a min. thickness for
> the flywheel (nor do the Haynes or Chilton manuals).
>
> That seems very odd -- I would've thought that the flywheel
> would have a minimum thickness (just like brake rotors).[/color]




Yeah, I would have thought that too, but I guess there's already so much
mass that minimum thickness isn't an issue. Unlike brake rotors, a flywheel
does double duty: It both smooths out engine vibrations and provides a
friction surface. Flywheels also don't have to soak up the kind of heat
that brakes do.

Just looked through my factory manual for our '99 Tercel. It too does not
give a thickness, just maximum runout, which is given as .031".




--
TeGGeR®

"TeGGeR®" <tegger@tegger.c0m> wrote in
news:Xns97BDF27F3A612tegger@207.14.113.17:
[color=blue]
> [email]ted@estaff05.mayfield.hp.com[/email] (Ted Johnson) wrote in
> news:e3oiok$a3r@estaff05.mayfield.hp.com:
>
>[color=green]
>>
>> Q#1: should I machine the flywheel when I replace the
>> clutch, or
>> just use some 80 grit sandpaper (by hand)?[/color]
>
>
>
>
> Don't sand it. Get it machined. The machine shop will know
> what to do. You need that surface flat and true, not
> roughened. Machining is cheap, less than $50.
>
>[color=green]
>>
>>
>> Q#2: what's the minimum flywheel thickness?
>> The Toyota Service Manual doesn't specify a min.
>> thickness for the flywheel (nor do the Haynes or
>> Chilton manuals).
>>
>> That seems very odd -- I would've thought that the
>> flywheel would have a minimum thickness (just like
>> brake rotors).[/color]
>
>[/color]

Have never done this myself but have been told that if you have
the flywheel machined you may have to use shims to compensate
for the amount of surface removed since the clutch does not have
an adjustment. When I have done clutch jobs in the past I did
NOT use shims but did notice that pedal travel\engagement point
was considerably different(longer\higher) with new clutch if
the flywheel was resurfaced. This may have been corrected by the
use of shims. Just a thought
dc

"doncee" <nodbcspam9814wanted@charter.net> wrote in message
news:Xns97BE2ABB31EEDmedbcSWBEll@216.196.97.131...[color=blue]
> Have never done this myself but have been told that if you have
> the flywheel machined you may have to use shims to compensate
> for the amount of surface removed since the clutch does not have
> an adjustment. When I have done clutch jobs in the past I did
> NOT use shims but did notice that pedal travel\engagement point
> was considerably different(longer\higher) with new clutch if
> the flywheel was resurfaced. This may have been corrected by the
> use of shims. Just a thought
> dc[/color]

Doncee,

Where exactly would you insert the shims, and why? The clutch cover would
bolt to the flywheel & all internal clutch dimensions would be the same - or
more accurately restored to original specs.

Cutting 60 thousanths off the flywheel would just move the friction disk
that much down the transmission input shaft (closer to the engine)

In any case such a small amount would be trivial compared to friction
surface wear, which is the likely reason that you experienced difference in
pedal travel and engagement point. Or were you taking them apart for fun,
without renewing the friction surface?
--
Mike Harris
Austin, TX

"Mike Harris" <harrisremovethiswest@sbcglobal.net> wrote in message
news:oI08g.68460$> Where exactly would you insert the shims, and why?

It depends on the type if clutch cover. If its the flat type, you dont need
shims. If its a step type, and the friction surface has been ground .060,
the steps have to be ground .060 as well. Othewise the release bearing has
to push further in to release the clutch. Shims can be placed behind the
release bearing as necessary.

Stewart DIBBS

If the fly wheel is not burned blue or does not have groove/gouges in it --
it does NOT have to be surfaced/ground/milled. Roughing up with sand paper
is just fine. Have done many clutch replacements and only once had to have
flywheel milled -- it had heavy gouges and blue burn marks.

"Ted Johnson" <ted@estaff05.mayfield.hp.com> wrote in message
news:e3oiok$a3r@estaff05.mayfield.hp.com...[color=blue]
> I've got a question about resurfacing (machining) the flywheel
> when I replace the clutch (disk, throwout bearing, and pressure place)
> on a 1987 Toyota Tercel, 3E engine, 4 speed manual xmission, 150k miles.
>
> I've actually got the official Toyota service manual for this car, which
> details all the repair procedures. The manual seems quite thorough,
> however... the section regarding replacing the clutch says nothing
> about machining the flywheel. Instead, it says to REPLACE it
> "if necessary".
>
> The Haynes and Chilton manuals do say the flywheel should be
> resurfaced. But... they don't say what the minimum flywheel
> thickness is?!
>
> Q#1: should I machine the flywheel when I replace the clutch, or
> just use some 80 grit sandpaper (by hand)?
>
>
> Q#2: what's the minimum flywheel thickness?
> The Toyota Service Manual doesn't specify a min. thickness for
> the flywheel (nor do the Haynes or Chilton manuals).
>
> That seems very odd -- I would've thought that the flywheel
> would have a minimum thickness (just like brake rotors).
>
> Thanks in advance,
> -Ted[/color]

Thanks for all the good feedback gentlemen!
I do have a few follow-up questions though...
[color=blue]
>Don't sand it. Get it machined. The machine shop will know what to do.[/color]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
One would hope.

Unfortunately I don't have much experience/data with the few machine
shops in my area, so I don't know what their competence level is.

It would be "unfortunate" if I were to:
o remove flywheel from Tercel
o borrow my wife's car to take the Tercel flywheel to the machine shop
o later that day, borrow car again to go pick up flywheel
o reinstall the flywheel, and put everything else back together

only to find that the flywheel machining job they did is... less than ideal.

Thinking out loud for a sec... maybe I should go ahead and just buy a
new 'genuine Toyota' flywheel ($250) and avoid all the downtime and
hassle caused by a poorly machined flywheel? That would significantly
reduce my DIY savings, but then again I'd still be saving $400+
of labor... I hear doing clutches is a PITA, so I'm not looking forward
to doing this job twice :-/

Am I being overly paranoid here?

----
Regarding the min. flywheel thickness:
[color=blue]
>... but I guess there's already so much mass that minimum thickness
> isn't an issue. Unlike brake rotors, a flywheel
>does double duty: It both smooths out engine vibrations and provides a
>friction surface. Flywheels also don't have to soak up the kind of heat
>that brakes do.
>
>Just looked through my factory manual for our '99 Tercel. It too does not
>give a thickness, just maximum runout, which is given as .031".[/color]

If the flywheel gets machined, say 0.050" thinner, doesn't that
move the xmission input shaft 0.050" closer to the crankshaft?
===> at some point (say, if this is the car's 4th clutch)
there might be so much machined off the flywheel that
the xmission input shaft is now too "long" for the xmission
housing to bolt back onto the back of the engine...?

Your thoughts?

Thanks again,
-Ted

[email]ted@estaff05.mayfield.hp.com[/email] (Ted Johnson) wrote in
news:e3rp6p$ofg@estaff05.mayfield.hp.com:

[color=blue]
>
> Am I being overly paranoid here?[/color]




Yes. Auto machine shops do this sort of thing every single day of the week.
Don't worry about it.


--
TeGGeR®

"Ted Johnson" <ted@estaff05.mayfield.hp.com> wrote in message
news:e3rp6p$ofg@estaff05.mayfield.hp.com...
[color=blue][color=green]
>>Don't sand it. Get it machined. The machine shop will know what to do.[/color]
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^[/color]

I've done it both ways. The friction surface seems to last longer if the
flywheel is turned, but this is based on the dozen or so clutch jobs I've
done; YMMV. I also like the nice, shiney-new surface and the knowledge that
the job is done *right* but that's just my OCD showing. <G>
[color=blue]
>
> Unfortunately I don't have much experience/data with the few machine
> shops in my area, so I don't know what their competence level is.
>
> It would be "unfortunate" if I were to:
> o remove flywheel from Tercel
> o borrow my wife's car to take the Tercel flywheel to the machine shop
> o later that day, borrow car again to go pick up flywheel
> o reinstall the flywheel, and put everything else back together
>
> only to find that the flywheel machining job they did is... less than
> ideal.
>
> Thinking out loud for a sec... maybe I should go ahead and just buy a
> new 'genuine Toyota' flywheel ($250) and avoid all the downtime and
> hassle caused by a poorly machined flywheel?[/color]

You might could call around for a good price at a junkyard, then have that
machined. On "clutch day" you can just swap. Your risk is if the flywheel
is somehow damaged (e.g. cracked), or that you've purchased the wrong
flywheel, not having the old one for comparison. If you choose this route
be sure the ring gear is in good condition.
[color=blue]
> Am I being overly paranoid here?[/color]

Possibly. I've never had a problem with a machine shop turning flywheel or
brake parts. It's a fairly simple task. My own choice, not knowing your
local options, would be to disassemble, drop the flywheel off at the machine
shop, take the old clutch parts to the store to compare with the new and
insure that I'm getting the correct replacements, then swing back to pick up
the machined flywheel.

Given that I have a reliable and trusty brake and clutch specialty shop in
my town, I would probably take all down to them on a single trip. They will
turn the flywheel at no charge if you buy the clutch components from them.
Check your yellow pages under "clutches."
[color=blue]
> If the flywheel gets machined, say 0.050" thinner, doesn't that
> move the xmission input shaft 0.050" closer to the crankshaft?
> ===> at some point (say, if this is the car's 4th clutch)
> there might be so much machined off the flywheel that
> the xmission input shaft is now too "long" for the xmission
> housing to bolt back onto the back of the engine...?[/color]

No; that's determined by the bell housing. The TB will need to move closer
to the engine to disengage the clutch but most clutches have enough latitude
in the adjustment to compensate for this. And, as another poster advised
me, the TB can be shimmed if needed although I've never had to do this.

Oh, and speaking of transmission input shaft, at the risk of belaboring the
obvious - don't forget a new pilot bearing.
--
Mike Harris
Austin, TX

Ted Johnson wrote:[color=blue]
> I've got a question about resurfacing (machining) the flywheel
> when I replace the clutch (disk, throwout bearing, and pressure place)
> on a 1987 Toyota Tercel, 3E engine, 4 speed manual xmission, 150k miles.[/color]

You arent meant to skim flywheels *really* though they did do many
moons back, hence no info about it. If you are going to get it done
make sure its a TINY amount removed, dont take it to a know-nothing
mahinist - ive heard of some people having theirs reduced to below
safe levels and burst when the engine was pushed - saw-toothed chunks
of flywheel firing through the bodywork isnt fun.
You could always buy an aftermarket one if it is cheaper (certainly is
for my celica)

J

Yeah, next time you're buzzing your front drive Toy near or past the
redline, keep in mind that all that rotating flywheel/clutch mass is aimed
right at your crotch.<g>

Lee Richardson
Mech-Tech

[color=blue]
> You arent meant to skim flywheels *really* though they did do many
> moons back, hence no info about it. If you are going to get it done
> make sure its a TINY amount removed, dont take it to a know-nothing
> mahinist - ive heard of some people having theirs reduced to below
> safe levels and burst when the engine was pushed - saw-toothed chunks
> of flywheel firing through the bodywork isnt fun.[/color]

In article <jO2dnY1bY6yZi_7ZRVn-pw@sigecom.net>, [email]mechtech@sigecom.net[/email]
says...[color=blue]
> Yeah, next time you're buzzing your front drive Toy near or past the
> redline, keep in mind that all that rotating flywheel/clutch mass is aimed
> right at your crotch.<g>
>[/color]
It is in the US, In the UK and Japan people are smart enough to drive
over on the other side.

But the same could be said for a stock, machined or "performance" light
flywheel.

Anyway, moot point, as Coyoteboy's celica aint FWD.
--
Carl Robson
Car PC Build starts again. [url]http://smallr.com/rz[/url]
Homepage: [url]http://www.bouncing-czechs.com[/url]

NeedforSwede2 wrote:[color=blue]
> It is in the US, In the UK and Japan people are smart enough to drive
> over on the other side.
>
> But the same could be said for a stock, machined or "performance" light
> flywheel.[/color]

It'd take out my missus instead :o( dont think she would find that
funny. A performance one *should* be tested and withing limits.
[color=blue]
> Anyway, moot point, as Coyoteboy's celica aint FWD.[/color]

Its a transverse mounted 4wd actually, so same engine location as the
FWD versions.