[ihc] RE: Glessie's bad vibes

["Jim Grammer" <jgrammer@xxxxxxxxxx>]

>Date: Thu, 17 Jun 2004 10:59:22 -0700
>From: "Bill Fowler" <bill_fowler@domain.elided>
>Subject: [ihc] Glessie whine/hum/buzz

>So there is this sort of whine,  actually more of a hum or vibration when I
>get the ol gal up to about 30-40 mph steady.  It sounds as if it coming
>from the front end or perhaps the drive train under the floorboards.  You
>can actually feel the vibration in the floorboards.

Whines are generally gear noise. Hum/vibration more likely u-joints as
already suggested. I *know* I inspected them all after I got the truck, I
*think* I replaced at least one of the rears. Neither here nor there at this
point, as Steve mentioned if there's any play replace. At least u-joints are
cheap and the labor straightforward, you can do them yourself no problem.

>BTW (Jim) what the heck is that 1 square steel member that is bolted from
>the back of the clutch housing to the transfer case?  Some sort of
>stiffener?  Does not look stock to my highly trained eye ; <).

Good call, 'tho' I'm pretty sure it runs from the back of the tranny to the
t-case ;). IH's divorced t-case mounting essentially turns the t-case into a
pendulum attached to an x-member that is not perfectly stiff. There has
always been a known problem with the t-case 'winding up' on torque
application. Under just the right conditions that windup turns into an
oscillation of rapidly increasing amplitude. You get off the throttle QUICK,
'cause it feels like the driveline is gonna come up through the floor! It's
more likely to happen on manual tranny trucks, but not unheard of with
automatics. Back in the day, there was a field fix in the form of a tranny
to t-case brace(supposedly a service bulletin, I don't have a copy). Gary
Vukich in Modesto claims to have developed the fix, which I believe was a
chunk of all-thread with a bracket welded to one end and a bracket welded to
a coupling nut(with a jam nut)on the other end. My details are sketchy,
there was one on my '70 1200 and that sold some years back. I keep meaning
to crawl under the truck(now painted red, belongs to Rich B.) at IHWR and
look but I never remember while I'm there.

Anyway, my version on Glessie is a field expedient version using materials
that were on hand and seems to do the job. Note to others - if you plan to
use the tranny rear bearing retainer fixing bolts to mount a brace, make
sure the new longer bolt you need does *not* protrude into the tranny case.
The gears are REALLY close to the inside face of the case....

My '68 1100 actually has a separate x-member across the bottom of the frame
rail(IIRC, installed by a PO) with brackets that hold the lower end of the
t-case.

Jim