Chewed up flywheel

#11

"DougW" <I.only.read.usenet (AT) invalid (DOT) address> wrote

Quote:

Jo Baggs wrote:
"Jeff Strickland" wrote...
"Jo Baggs" wrote...
My friend's 1975 Jeep CJ-5 with an unknown 8 Cyl Engine (not stock
i.e. 304).
The starter starting making the horrible fingernail on the
chalkboard sound. So we took the starter off and the edge of the
flywheel is ate up pretty bad (not all the way around, only in a
spot about 4" long along the gear). So can I get the flywheel
fixed, or do I need a new one? Also, not knowing the size of the
flywheel, are their many different
types? Or do Jeeps typically come with a 10" or 12" flywheel? From
what I can tell, it looks the original bellhousing (ironduke?).

Somebody might correct me here, but the Iron Duke was the 4-banger
engine, and nothing else.

Can you connect the starter to the battery and see if the noise is
still there? My guess is that the marks on the flywheel and the
noise yo report are not related. If so, the marks are probably not
important -- they've been there a long time, no point in worrying
abut them now. In any case, if you elect to go after the flywheel, it
would be a
good time to consider a clutch because you'll have it off anyway.

Jeff, Bill, and Doug,

We took the starter off today and the ring gear is chewed up in a
spot about 4" long. I looked at the starter gears. Should they be
straight up or are they curved a little like a helical gear? A
couple of the gears appeared to be angled i.e. not perpendicular to
the ground when it sits straight up.

Typical starter gear.
http://www.made-in-china.com/image/2f0j00cBgEwOPqrikoM/Starter-Gear-SG-02-.jpg

By "gears" do you mean "teeth" All the teeth should look alike.
The material in the starter gear is much weaker than the flywheel.
It's supposed to wear/break before the flywheel gear does... supposed to..
Possible it got buggered up when the missing teeth in the flywheel
came around and failed to mesh. Actually, take a close look at the
starters nose to make sure it's not cracked.

The starter is making the noise as it's not engaging the ring gear.
Rather, it's just grinding the shit out of the ring gear. There was
quite a bit of metal filings attached to the starter gear when we
took it off.

Alignment depends on the engine and starter mount. My ZJ just has two
bolts and that's it. The old C-10 had a small set of shims depending
on what brand of starter went in. I just put a bit of spraypaint
on the starter gear and stuck the starter in. Cranked the engine over
a few times (ignition disabled) then dropped it and looked at the pattern.

I actually had a hell of a time starting my old Chevy till I got under
and noticed there was only one bolt holding the starter on. :O
It was fairly buggered up, but the flywheel thankfully was undamaged.

--
DougW

Thanks Doug. The flywheel was pretty chewed up. Not sure why, but it was
chewed up nonetheless. So, if I go through the hassle of dropping the
tranny and pulling out the flywheel, where do I bring it to have a new ring
gear put on? Does NAPA do that?

#12

"Jo Baggs" <Jo (AT) says (DOT) shaddup> wrote

Quote:

"DougW" <I.only.read.usenet (AT) invalid (DOT) address> wrote in message
news:hbged6$1am$1 (AT) news (DOT) eternal-september.org...
Jo Baggs wrote:
"Jeff Strickland" wrote...
"Jo Baggs" wrote...
My friend's 1975 Jeep CJ-5 with an unknown 8 Cyl Engine (not stock
i.e. 304).
The starter starting making the horrible fingernail on the
chalkboard sound. So we took the starter off and the edge of the
flywheel is ate up pretty bad (not all the way around, only in a
spot about 4" long along the gear). So can I get the flywheel
fixed, or do I need a new one? Also, not knowing the size of the
flywheel, are their many different
types? Or do Jeeps typically come with a 10" or 12" flywheel? From
what I can tell, it looks the original bellhousing (ironduke?).

Somebody might correct me here, but the Iron Duke was the 4-banger
engine, and nothing else.

Can you connect the starter to the battery and see if the noise is
still there? My guess is that the marks on the flywheel and the
noise yo report are not related. If so, the marks are probably not
important -- they've been there a long time, no point in worrying
abut them now. In any case, if you elect to go after the flywheel, it
would be a
good time to consider a clutch because you'll have it off anyway.

Jeff, Bill, and Doug,

We took the starter off today and the ring gear is chewed up in a
spot about 4" long. I looked at the starter gears. Should they be
straight up or are they curved a little like a helical gear? A
couple of the gears appeared to be angled i.e. not perpendicular to
the ground when it sits straight up.

Typical starter gear.
http://www.made-in-china.com/image/2f0j00cBgEwOPqrikoM/Starter-Gear-SG-02-.jpg

By "gears" do you mean "teeth" All the teeth should look alike.
The material in the starter gear is much weaker than the flywheel.
It's supposed to wear/break before the flywheel gear does... supposed
to..
Possible it got buggered up when the missing teeth in the flywheel
came around and failed to mesh. Actually, take a close look at the
starters nose to make sure it's not cracked.

The starter is making the noise as it's not engaging the ring gear.
Rather, it's just grinding the shit out of the ring gear. There was
quite a bit of metal filings attached to the starter gear when we
took it off.

Alignment depends on the engine and starter mount. My ZJ just has two
bolts and that's it. The old C-10 had a small set of shims depending
on what brand of starter went in. I just put a bit of spraypaint
on the starter gear and stuck the starter in. Cranked the engine over
a few times (ignition disabled) then dropped it and looked at the
pattern.

I actually had a hell of a time starting my old Chevy till I got under
and noticed there was only one bolt holding the starter on. :O
It was fairly buggered up, but the flywheel thankfully was undamaged.

--
DougW

Thanks Doug. The flywheel was pretty chewed up. Not sure why, but it was
chewed up nonetheless. So, if I go through the hassle of dropping the
tranny and pulling out the flywheel, where do I bring it to have a new
ring gear put on? Does NAPA do that?

Yes, by gears I meant teeth. Sorry.

#13

Jo Baggs wrote:

Quote:

Thanks Doug. Â*The flywheel was pretty chewed up. Â*Not sure why, but it was
chewed up nonetheless. Â*So, if I go through the hassle of dropping the
tranny and pulling out the flywheel, where do I bring it to have a new
ring gear put on? Â*Does NAPA do that?

NAPA will just farm the job out to a local machine shop in most cases. Look
around for a shop that specialized in automotive machine work - they can
press that gear off/on easily - I've had them do while I waited. If it's a
good shop, they can also get you the right gear (or tell you where to get
it) and probably give you a good idea of just what caused the damage in the
first place.

--
Will Honea

#14

"Will Honea" <whonea (AT) yahoo (DOT) com> wrote

Quote:

Jo Baggs wrote:

Thanks Doug. The flywheel was pretty chewed up. Not sure why, but it was
chewed up nonetheless. So, if I go through the hassle of dropping the
tranny and pulling out the flywheel, where do I bring it to have a new
ring gear put on? Does NAPA do that?

NAPA will just farm the job out to a local machine shop in most cases.
Look
around for a shop that specialized in automotive machine work - they can
press that gear off/on easily - I've had them do while I waited. If it's
a
good shop, they can also get you the right gear (or tell you where to get
it) and probably give you a good idea of just what caused the damage in
the
first place.

--
Will Honea

Thanks Will

#15

Jo Baggs wrote:

Quote:

"Will Honea" wrote...
Jo Baggs wrote:

Thanks Doug. The flywheel was pretty chewed up. Not sure why, but
it was chewed up nonetheless. So, if I go through the hassle of
dropping the tranny and pulling out the flywheel, where do I bring
it to have a new ring gear put on? Does NAPA do that?

NAPA will just farm the job out to a local machine shop in most
cases. Look
around for a shop that specialized in automotive machine work - they
can press that gear off/on easily - I've had them do while I waited.
If it's a
good shop, they can also get you the right gear (or tell you where
to get it) and probably give you a good idea of just what caused the
damage in the
first place.

--
Will Honea

Thanks Will

If it's like a tractor flywheel then the teeth are a seperate ring
that's held on purely by friction. You basically cut the old ring
off then heat the new one up to about 200. After it's hot you just
drop it down on the flywheel and it shrinks to fit. I do not
recommend doing this yourself if you haven't done it before.

The reason I mentioned NAPA is they have a good parts crossreference.
I agree with Will that you should find a good local machine/engine shop.

--
DougW

#16

Chewed up in one spot is not unusual. Engines tend to stop at the same
point in rotation every time. There are four angles where the compresion
is least on an 8 cylinder, but for some reason it will favor only one
and that's where the ring gear will wear out. If this engine is
internally balanced, (No big segments machined or cast out of the
flywheel) one "fix" is to rotate the flywheel on the crank. The correct
repair is to replace the ring gear or flywheel.
--
jeff

Jo Baggs wrote:

Quote:

My friend's 1975 Jeep CJ-5 with an unknown 8 Cyl Engine (not stock i.e.
304).
The starter starting making the horrible fingernail on the chalkboard sound.
So we took the starter off and the edge of the flywheel is ate up pretty bad
(not all the way around, only in a spot about 4" long along the gear). So
can I get the flywheel fixed, or do I need a new one?

#17

"jeff" <jalowe44.invalid (AT) hotmail (DOT) com.invalid> wrote

Quote:

Chewed up in one spot is not unusual. Engines tend to stop at the same
point in rotation every time. There are four angles where the compresion
is least on an 8 cylinder, but for some reason it will favor only one and
that's where the ring gear will wear out. If this engine is internally
balanced, (No big segments machined or cast out of the flywheel) one "fix"
is to rotate the flywheel on the crank. The correct repair is to replace
the ring gear or flywheel.
--
jeff

Are you sure?!

I've never ever heard that theory -- the engine will stop in the same place.
It sounds like an absurdly implausible theory to me.

The engine will stop as soon as there is no spark to make it go, and it's
not gonna wait until it gets to the next compression stroke. There is a
compression stroke every 90 degrees of engine rotation, when the spark is
removed -- engine idle is assumed -- the motor will stop because of the
existing compression on which ever piston is at the top of its stroke plus
the building compression of the next cylinder in the order. Since the
flywheel goes around twice to fire all eight cylinders, the odds of it
stopping on the same 4-inch section with any regularity is very remote, and
is entirely based on the odds by the way.

PS
I ignore any condition or malfunction such as spontaneous combustion that
causes some motors to run on and on while you are walking into the
supermarket with smoke beltching out of the carburator and/or tailpipe. My
comments are confined to properly operating engines. Turn the key off and
the engine stops turning -- for any practical purpose -- instantly.

#18

"Jo Baggs" <Jo (AT) says (DOT) shaddup> wrote

Quote:

My friend's 1975 Jeep CJ-5 with an unknown 8 Cyl Engine (not stock i.e.
304).
The starter starting making the horrible fingernail on the chalkboard
sound. So we took the starter off and the edge of the flywheel is ate up
pretty bad (not all the way around, only in a spot about 4" long along the
gear). So can I get the flywheel fixed, or do I need a new one?

Also, not knowing the size of the flywheel, are their many different
types? Or do Jeeps typically come with a 10" or 12" flywheel? From what I
can tell, it looks the original bellhousing (ironduke?).

Thanks.

Ok, we'll drop the tranny this weekend. Is it easier to remove the tranny,
transfer case, and bell housing as one unit i.e. only remove the bell
housing bolts and drop the whole thing. Or, do I need to unbolt the tranny
from the bell housing, and then take off the bell housing?

Thanks

#19

Hi Jo,
I believe it is. I drill a hole the floor jack to bolt a chain in as
much a balanced position as possible. Shift the trans into direct before you
remove the top cover, will help in finding the disk, going back together.
God Bless America, Bill O|||||||O
mailto:BillHughes (AT) billhughes (DOT) com
http://www.billhughes.com/jeep_bookmark.htm

"Jo Baggs" <Jo (AT) says (DOT) shaddup> wrote

Quote:

Ok, we'll drop the tranny this weekend. Is it easier to remove the
tranny,
transfer case, and bell housing as one unit i.e. only remove the bell
housing bolts and drop the whole thing. Or, do I need to unbolt the
tranny
from the bell housing, and then take off the bell housing?

Thanks

#20

Jeff Strickland wrote:

Quote:

"jeff" <jalowe44.invalid (AT) hotmail (DOT) com.invalid> wrote in message
news:1255949525.814307 (AT) r2d2 (DOT) vermontel.net...
Chewed up in one spot is not unusual. Engines tend to stop at the same
point in rotation every time. There are four angles where the compresion
is least on an 8 cylinder, but for some reason it will favor only one and
that's where the ring gear will wear out. If this engine is internally
balanced, (No big segments machined or cast out of the flywheel) one
"fix" is to rotate the flywheel on the crank. The correct repair is to
replace the ring gear or flywheel.
--
jeff

Are you sure?!

I've never ever heard that theory -- the engine will stop in the same
place. It sounds like an absurdly implausible theory to me.

The engine will stop as soon as there is no spark to make it go, and it's
not gonna wait until it gets to the next compression stroke. There is a
compression stroke every 90 degrees of engine rotation, when the spark is
removed -- engine idle is assumed -- the motor will stop because of the
existing compression on which ever piston is at the top of its stroke plus
the building compression of the next cylinder in the order. Since the
flywheel goes around twice to fire all eight cylinders, the odds of it
stopping on the same 4-inch section with any regularity is very remote,
and is entirely based on the odds by the way.

PS
I ignore any condition or malfunction such as spontaneous combustion that
causes some motors to run on and on while you are walking into the
supermarket with smoke beltching out of the carburator and/or tailpipe. My
comments are confined to properly operating engines. Turn the key off and
the engine stops turning -- for any practical purpose -- instantly.

Jeff, mine always stops at the same place: 180 degrees from where I want it
to stop so that I have to manually rotate it the maximum amount. I think
that's due to Murphy rather than mechanics, though. You're analysis is
right on.

My tiring 6 with 200k on the clock will hold the thing on one hill where I
frequently park about one time in 10 - probably because the cylinder with
the best compression is on the compression stroke when the engine stops.
Any other combo will let it slowly creep past tdc, then gain enough
momentum before the next cylinder gets to tdc to just keep creeping right
on down the hill.

--
Will Honea