Stovebolt.com Forums The Shop Area Driveline Cork torque tube ball seal

Thanks... I'll pass this on to him..

You might want to Read This First.
Benefit of a torque tube driveline:
"You should mention about closed drive shafts is their absolute impervability to rear spring wind up" (Wheel Hop)

Thanks Jorb

I just read that.. It seems, at first and second glance, to lay fault on the rear ends geared in the 4:10/original range.. Mine had been changed to 3:55 a couple years ago

jorb,

I do not understand your distinction with regards to the presence of a "ball seat" in the various transmissions.

Any manual shift SM420 4-speed transmission could have a removable/interchangeably cast-iron rear-housing for an enclosed drive-shaft/u-joint "ball seat"; or, any SM420 could have a cast-iron rear-housing for an open drive-shaft/u-joint.

The cast-iron fitting/housing/cover ("tail housing" - rear housing?) on the rear of the SM420 transmission is interchangeable among all SM420 years. Any SM420 could be set-up for open driveshaft or closed driveshaft (with the appropriate rear housing).

This is very convenient.

Tim,

Let me re-word what I meant to say.
The very end of the tail housing on the Hydra-Matic and Powerglide transmissions is cast/shaped different,
than the very end of the tail housing on the 3 or 4 speed manual shift transmissions.
End of the HM tail housing
End of Manual Shift trans Fig. 22 and 23

In order for the U-Joint Ball Housing to fit properly onto the end of the tail housing of the Hydra-Matic and Powerglide transmissions.
GM stamped out a piece of metal (ball seat) which is placed on the end of it's tail housing. Ball Seat in Place,, Master Parts Catalog Group # 5.565 Seat
First the Rubber O Ring 1, Rubber O Ring 2 is placed into the grove, then the Ball seat.

Now the very end of the HM tail housing has the same shape as the tail housing end of the 3 or 4 speed manual shift transmission.
You could say the ball seat is cast right into the end of the tail housing of the 3 or 4 speed manual shift transmissions.
Therefore no need for a separate stamped out piece, for the 3 or 4 speed manual shift transmissions.

I really don't understand why GM didn't cast the ends of the HM & PG tail housings,
the same as the 3 or 4 speed manual shift tail housings.

Maybe I'm totally off base here (wouldn't be the first time), but I think we're talking about the cork seal that goes at the rear of the ball. The collar that holds the ball in place is adjusted by adding or removing paper (thin cardboard) shims. On the other end is the cork seal that that seals the rear of the ball to the front of the torque tube.

It sounds to me like the mechanic isn't using the two metal retainers that go on either side of the cork. It's a PITA to get it in there, but it seals pretty well. The two washers surround the cork and protect it. Without the washers the cork would be destroyed in no time. Is this the problem?

Never seen a problem with the cork piece that fits inside the collar. I guess you could tear it up if you put it in too tight, but seems questionable. When I redid mine I put a little gear lube on the facing surface of the cork and adjusted it by adding the cardboard gaskets before I reattached the U-joint. Check your shop manual, it tells how to do it. Then you'd know it was installed properly.

David,

I think the cork seal in this set is what is being discussed. The smaller rear seal that you are referring-to is the rubber seal that is inside the cork seal (in the illustration).

I have never used a cork seal in that location - maybe some sets provide a cork seal.

Yep, last one I did had a cork gasket in the rear. Only thing that I can imagine would tear up the front one is the ball surface being rough or warped in some way. Seems like that would be easy to see, though.

...cork seal...

...test...to many shims...


...seal with metal rings...

The OP = Original Poster "Dogface" of this Thread,
Did say' "Seal" {Needs to be I.D of more than 4",} in a earlier POST or as above.
So, it was the ball collar cork seal He was alluding to.
But, I have seen some Seal Kits that use a cork seal in the torque tube Retainer screw on ring. I prefer rubber.
I have not seen a rubber ball collar seal, only cork.

It could be a combination of both.
The ball collar is smooching the cork seal because of incorrect number of shims and a nicked up ball housing.