Case insert loose

 Howdy,

Any opinions on what to do?  The IT175 main bearings that
I thought were loose and in need of replacement are fine.
However, the steel insert that is cast into the aluminum
cases is loose in the case.  On the order of .005 slop.

I'm considering cleaning as much as I can (ultrasonic),
shimming in three places, then using wicking loctite.  The
shims will keep the steel insert in the right-ish place.
Let the loctite cure.

Pull the shims and do loctite again.

I think this area is cool enough for the loctite.

Found one case half new and it's $287.55.  Not available
from Yamaha, NOS only.  Can't find the other side.  Would
just buy a couple bottom  ends off Ebay but now that I've
seen it, I remember seeing this condition once before.
On a similar vintage YZ125.  Chances are lots of them
are bad.


Go fast. Take chances
Mike S.

 Is there enough material in the aluminum to bore it out then use special
made over sized O.D. inserts? At least that way you'll be sure the
bearings line up better. Or if you're doing it "on the cheap" that
Loc-Tite does really work. I fitted a barrel bushing on a Beretta 92FS
pistol using Loc-Tite and it's held for thousands of rounds. Normally,
barrel bushings on that type of pistol are silver soldered in place. But
that requires refinishing the black on the slide. Four drops of Loc-Tite
has worked just as good as soldering.

 Mike Corey asks:


Doesn't look like it.  I think the insert is hat shaped which makes it
worse.  Would not like to bore it out and find out there's not enough
material left.


Go fast. Take chances.
Mike S.

 Mike "MacGyver"  Sturd ponders;


..I've seen this "repair" similarly performed with JB Weld.  Mix the JB
Weld and "liquify" it with a blow dryer.  Properly prepared shim stock
pieces were _not_ removed however.  Assemble the case halves with crank
and snug.  Set aside with crank in vertical position and don't touch,
spin, wiggle or wonder for 24 hours.  
  This was a circa 78'-80' problem as I recall rooted in some poorly
aligned crank assemblies.
  Naturally your efforts will be fruitless if your crank assembly isn't
near zero runout (it is possible!)

Best Regards & Good Luck!

Mike Baldwin

 Michael Baldwin suggests:


Will that seep into a 0.002" gap?  I know that the
wicking loctite will, that's why I thought of it.

Remaining good advice noted.


Go fast. Take chances.
Mike S.