Companion Flange (Transfer Case Junction)

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Date: Mon, 05 May 1997 12:05:59 EDT
From: markadrian@juno.com (Mark D Adrian)
Subject: Leaky companion flange
To: Toy4x4@tlca.org

Although I had  this problem was several months ago, I thought I'd report
it now since it came to mind.  I had occasionally noticed several
splatters of grease/oil on my rear axle's housing and diff. I thought
this was from over-lubing the U-joints. However, the evidence led me to
look a little further and I noticed a gear oil leak eminating from what's
called the "rear companion flange".  This is the component that connects
the front of the rear drive shaft to the transmission's shaft. So, after
consulting with my local independent, I learned that what's common is,
after many rough miles, for the lock-nut inside the flange, to work
itself loose, which allows fluid to drain. The extreme degredation is for
the nut to come completely off (or near off) and have the shaft fall off
and you pole-vault the truck. So, it was a fairly simple repair. I needed
a new seal, new nut and some of that really-expensive Toyota FIPG (the
orange stuff). When I broke it all down, I was surprised to see how loose
the nut had become, it was totally loose with absolutely NO torque on it
despite the lock-notch that's chisled in at the factory. One questions
the design here. Anyway, after peeling back that stubborn lock-notch, it
came right off.  Then, while I was in there, I very, very carefully
extricated the seal so as not to scratch, mar, or dent the housing's
surface. It all went back together very easily and the leak/seep has
since stopped. I took great pains to clean off all the old FIPG to assure
a clean/fresh seal with the new FIPG. So, yet another fairly-simple
repair that I'm sure Toyota would have wanted $100s to do.

Mark

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Date: Mon, 05 May 1997 00:59:32 -0400
From: Bob Bascom 
Subject: Leaky companion flange
To: Toy4x4@tlca.org

Mark D Adrian wrote:
> 
> Although I had  this problem was several months ago, I thought I'd report
> it now since it came to mind.  I had occasionally noticed several
> splatters of grease/oil on my rear axle's housing and diff. 
> Mark
Whats FIPG?  I just did my companion flange seal and I didn't put any of
that stuff on. Should I open it back up and redo it.  BTW my nut didn't
have any torque on it either.
Ryan Bascom
bascom@erols.com

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Date: Mon, 05 May 1997 23:09:21 EDT
From: markadrian@juno.com (Mark D Adrian)
Subject: Leaky companion flange
To: Toy4x4@tlca.org

Whats FIPG?  I just did my companion flange seal and I didn't put any of
that stuff on. Should I open it back up and redo it.  BTW my nut didn't
have any torque on it either.
Ryan Bascom
bascom@erols.com

- --------------

Ryan,  FIPG is an (industry standard ?) abbreviation for Form In Place
Gasket. I bought a tube from the Toyota dealer for $20. I smeared it on
the threads where the nut screws on to the transmission's splined
"output" shaft. I've heard that the Toyota FIPG is "the" best. The Toyota
manual I think instructs to use it, so you probably should. You should
have seen the original FIPG when you removed the flange. There was plenty
on mine and that was enough evidence to cause me to use FIPG again with
or without the manual's direction. You can buy after market FIPG that
would probably work OK. Again, as everywhere else, you get what you pay
for. If you get it from Toyota, be sure you ask for the transmission
variant because they also make an FIPG for the engine.

Mark

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Date: Tue, 6 May 97 09:48:02 PDT
From: barney@flowpoint.com (Barney McNamara)
Subject: Leaky companion flange
To: Toy4x4@tlca.org

Mark wrote:
>I learned that what's common is,
>after many rough miles, for the lock-nut inside the flange, to work
>itself loose, which allows fluid to drain. The extreme degredation is for
>the nut to come completely off (or near off) and have the shaft fall off
>and you pole-vault the truck. 

Been there too, when I first got my truck (182,000 miles) my front u-joint 
was real loose. The guy who patched it up (before I became a u-joint expert)
said that the flange was loose. So after the emergency u-joint fix, I took
it in to my regular mechanic near home. He found the nuts holding both
flanges (front and rear) to the transfer case were loose. The suggestion
was that the lose flange had caused the u-joint failure. The seals were
replaced and the nuts tightened up. Now my rear-rear u-joint has failed
after being replaced 15,000 miles ago. I'm thinking the slop in the pinion
bearing is causing excessive stress on the rear u-joint and I'm saving for
a differential overhaul and locker :-)
______________________________________________________________
Barney McNamara              JENNY - 83 Toyota Short Bed  
( barney@flowpoint.com )     stock 22R motor ; 3" body lift
Santa Cruz, Ca.              8" alloy rims; 31" BFG A/Ts
______________________________________________________________

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