[GMCnet] Onan flywheel removal

[Tyler]

Trying to remove flywheel on Onan yesterday to fix/replace my starter bracket...

Found this thread
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&goto=176648&rid=3615&srch=onan+flywheel+bolt#msg_176648

I got a HF puller set (not the one Jon recommends, but other threads did) and the bolts did not seem right to set in the flywheel. Jon mentions buying
3/8 bolts in his thread, but I tried 16 thread and 24 thread, and 24 is definitely not it, and the 16 will only seat about three or four threads in. I
am nervous driving it in too hard, because the flywheel metal has already pocked a bit on the first attempts. As in, pulled the first thread or two
out.

And, assuming I can get a good bite into the flywheel, can I use my impact driver to turn the puller bolt? I have read to never use the impact putting
the flywheel back on, but I don't see how to hold the flywheel from spinning and turn the puller bolt while getting it off.

All advice welcome. Thanks.


--
1975 Glenbrook
Raleigh, NC
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[Jon Roche]

I am almost certain those are course thread grade 8 bolts that I used.

with that particular puller I did not use any impact wrench. I think I just used my ratchet wrenches, it came off almost instantly. That puller
must assert the right force in the correct place.

I am not sure what harbor freight one you used, but I remember the one I bought from Oreily's made the job simple.


--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

[Jim Miller]

It might not be a bad idea to chase the flywheel’s threads with a tap before screwing in the puller bolts and it wouldn’t be a bad idea to apply a liberal dose of anti-sieze compound on the puller’s jack bolt before attempting the operation. I often use an impact wrench on pullers - but I start out with a reduced amount of impact force and then work my way up if necessary. I’ve also been known to apply firm pressure with the puller and then tap the end of the puller bolt with a lead or bronze hammer in order to break tapers loose.

--Jim "saving the lives of Onans...one unit at a time" Miller
1977 Eleganza II
1977 Royale
Hamilton, OH

[gene Fisher]

On Wed, May 27, 2015 at 5:27 AM, Jon Roche <lqqk...@gmail.com> wrote:

> I am almost certain those are course thread grade 8 bolts that I used.
>
> with that particular puller I did not use any impact wrench. I think I
> just used my ratchet wrenches, it came off almost instantly. That puller
> must assert the right force in the correct place.
>
> I am not sure what harbor freight one you used, but I remember the one I
> bought from Oreily's made the job simple.
>

> ​link?​

>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>

--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html

[Matt Colie]

Tyler,
Listen to Jim Miller. Chase the puller threads.
Any lubrication on the puller threads will help it work.
I have never needed an impact pulling a flywheel, but if you take it up the ratchet load and give it a shot with a light hammer, that usually works on
Onan flywheels.

WORD OF CAUTION about installing the flywheel.
BELIEVE the torque in the manual. There are more than a few Onans with cracked flywheels. Anytime someone gets too heavy with the retaining force -
SNAP.

Matt


Tilerpep wrote on Wed, 27 May 2015 07:10

> Trying to remove flywheel on Onan yesterday to fix/replace my starter bracket...
>
> Found this thread
> http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&goto=176648&rid=3615&srch=onan+flywheel+bolt#msg_176648
>
> I got a HF puller set (not the one Jon recommends, but other threads did) and the bolts did not seem right to set in the flywheel. Jon mentions
> buying 3/8 bolts in his thread, but I tried 16 thread and 24 thread, and 24 is definitely not it, and the 16 will only seat about three or four
> threads in. I am nervous driving it in too hard, because the flywheel metal has already pocked a bit on the first attempts. As in, pulled the first
> thread or two out.
>
> And, assuming I can get a good bite into the flywheel, can I use my impact driver to turn the puller bolt? I have read to never use the impact
> putting the flywheel back on, but I don't see how to hold the flywheel from spinning and turn the puller bolt while getting it off.
>
> All advice welcome. Thanks.


--

Matt & Mary Colie - Members GMCMI, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

[Larry Davick]

The shaft is slightly conical so when pulling, once you get past the initial resistance, the thing comes off very easily. This conical shape is also the reason it is so very important to install the flywheel with a torque wrench and not a bubba hammer. Too tight will crack the flywheel.

Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, CA

[Tyler]

Progress...rented a tap and die set, made easy work of setting the pull bolts.

Picked up a timing gear puller, but did not like how the taper went into the center. This was the kit I already had bought at HF
http://www.harborfreight.com/bolt-type-wheel-puller-set-69889.html
and it had a flat, round pressure point that fit perfect. The rig proved strong enough. I did use my impact because motor would spin as I tried to
turn bolt. Snugged it, nothing to lose (I lied to myself), a little more air, and a pleasant pinging POP and it was free.

So next questions into the Onan, not sure if warrant another thread -
the starter bracket is broken, and clearly has been sitting on the frame and actually worn the bracket and lower bolt smooth. I am installing new
mount cushions but if they are not enough to raise it clear, is there a way to adjust the overall height of the onan in/on the slides?

If I use my cheap HF welder to put my bracket back together will it hold? I am aware of replacements for about $50, but I want to play/learn my
welder, and I would like it back together tomorrow. This metal almost looks crumbly to begin with.

And...took the choke off and multiple parts fell out of it. Can't find any pictures of the mechanism on forum or pic site. It looked like a hinge pin
was missing off one side, any photos available showing the moving parts that go against the exhaust manifold?

While I am at it, I'll post another thing others may need to look for that was out of sight - I have a fiberglass mat like something for insulation in
the gen compartment. It is falling apart/down. when I pulled some covers to clean mud daubers out of the cooling fins, realized that the hair like
stuff had been sucked in and packed the back side of one cylinder nearly completely blocking air flow. If you have this hair mat stuff, check it out.
To replace that, is there a fireproof, metal backed insulation that I can get at Home Depot or the like?

[Robert Mueller]

Tyler,

Don't bother with welding the Onan starter bracket it's only going to break again unless you're real good welder.

Just get one of these:

http://www.appliedgmc.com/prod.itml/icOid/812


Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426

[Larry Davick]

Also when pulling off the flywheel I usually loosen the center bolt and push against it with the puller.

Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, CA

[Len Novak]

I checked out the above link, I have a loose started bracket. Made the pIunge and bought the aftermarket one, I just need to get the flywheel
Off now. Any links to the correct puller ?
--
Len Novak, 76 Eleganza II, Las Vegas

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[Matt Colie]

Terra,

Any small two bolt puller will work.
See if you can borrow one from AutoZone. They aren't expensive, but free is better.
When you go to put it back on, BE Careful and use a torque wrench NOT AN AIR WRENCH.

Matt
Terrasmak wrote on Sat, 01 August 2015 18:07

> I checked out the above link, I have a loose started bracket. Made the pIunge and bought the aftermarket one, I just need to get the flywheel
> Off now. Any links to the correct puller ?


--

Matt & Mary Colie - Members GMCMI, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

[Robert Mueller]

Len,

There's a picture of the puller in MM X-7525 / Section 24C - Onan Motor Generator / Page 24C-32 / Figure 50 - Pulling Flywheel with
Straight Bar Puller.

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Len Novak

I checked out the above link, I have a loose started bracket. Made the pIunge and bought the aftermarket one, I just need to get the
flywheel Off now. Any links to the correct puller ?
--
Len

[Len Novak]

Well it's off, used a harmonic balancer puller from autozone ($20 don't think I'm returning the rental ) and I think I already have the upgraded
bracket. All 3 bolts were loose, the bottom bolt thru the muffler bracket the threads are stripped. Time for a heli coil , a little sheet metal
hardware to replace a could missing bolts and back together. The oil pressure/filter housing was pretty loose , tightened it and got a lot of crud out
from the cooling fins.


I have a feeling the spare bracket is going on my dads coach next time I head home to see him.

--
Len Novak, 76 Eleganza II, Las Vegas

[Larry Davick]

I had the same feeling when I installed the ragusa bracket. I didn’t see anything wrong with the one I was removing, but since I had the new one I installed it. The starter motor has always engaged perfectly since, so I feel as if I made the right choice.

Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, CA

[Len Novak]

3/8-18 helicoil in Vegas is a pain. Of course I have no real hardware stores on my side if town. I'll probably end up ordering a kit