1967 Driveshaft Front Yoke Plug Leaking - What is a suitable replacement?

[P. Manoogian]

Leaking out weep hole in front of u joint. Rear extension seal is new and not leaking. It appears a sponge like material in in the hollow of the yoke.


This is a rebuild driveshaft. The TSM suggest that there is a "plug" on the slip yoke that is specific to commercial and fleetwood. It also suggests that this is an area to check for leaks.


Hence I am wondering what you may have used to replace this "plug."


Thanks

[bcroe]

There are a couple different driveshaft arrangements.  One is a simple
splined shaft that the yoke slides over, inside the rear seal.  This yoke
should NOT have a center vent such as you described. 

The other uses a much longer yoke, which has an outer sleeve
extending inches beyond the splines, smooth inside.  The sleeve
seals on an O ring on the output shaft, forward of the splines.  So
this style yoke needs a vent in the center.  If this yoke is used
without the O ring, or the O ring has failed, you will have a leak. 
Bruce Roe

[P. Manoogian]

According to the TSM the one with the vent hole was used on Commercial Chassis and Fleetwood. The car I am working on is a Deville. The driveshaft is a used unit that likely came from a Fleetwood. I have put a rubber plug with silicone as well as several layers of silicone impregnated gasket material cur to diameter. I think it will work. Will keep you posted.

[bcroe]

According to the TSM the one with the vent hole was used on Commercial Chassis and Fleetwood. The car I am working on is a Deville. The driveshaft is a used unit that likely came from a Fleetwood. I have put a rubber plug with silicone as well as several layers of silicone impregnated gasket material cur to diameter. I think it will work. Will keep you posted.

Yea, you are a victim of incompatible parts.  Fixes are
1. Plug the vent;
2. change to a trans output shaft with an O ring;
3. change the yoke;
4. put a drip pan under it. 

Here I put O ring output shafts in my transmissions, which
work for either yoke.  Bruce Roe

[cadillacmike68]

A Fleetwood drive shaft from 1967 is 3.5 inches longer than a DeVille drive shaft. How do you get the former in the latter without cutting and welding it???

[P. Manoogian]

It has already been cut and welded.

[cadillacmike68]

OK, that makes sense.

When you said:
"According to the TSM the one with the vent hole was used on Commercial Chassis and Fleetwood."

did you mean Shop Manual? and when by Fleetwood, did you by any chance mean Fleetwood 75 series? Because both the CC and 75 series used a split drive shaft. Fleetwoods, (680 & 681) used the same shaft as the DeVilles and Calais (682 & 683) , except that the Fleetwood 60 series cars had a 3.5" longer shaft.

I looked this up in my 1968 manual, and yes the extra seals, etc is only on 697 and 698 series cars. That's CC & F75 models. 

For you to have a CC / 75 series shaft, someone must have done some fancy cutting and welding with two shafts, because the front half of those shafts was not long enough.

[P. Manoogian]

Yup, a highly regarded drive line shop did the work.


I believe I sealed the leak though using the Black Permatex Ultra on a rubber plug similar to the plug you see on bleeder screws. I then used the layers of gasket material, a circular section of an old leather belt, some stick on thin weatherstrip, all coated with the Permatex Ultra. As of tonight the yoke is dry.


Thanks for taking interest in this.

[cadillacmike68]

Yup, a highly regarded drive line shop did the work.


I believe I sealed the leak though using the Black Permatex Ultra on a rubber plug similar to the plug you see on bleeder screws. I then used the layers of gasket material, a circular section of an old leather belt, some stick on thin weatherstrip, all coated with the Permatex Ultra. As of tonight the yoke is dry.


Thanks for taking interest in this.

Wow, that's a complex repair! Hey, as long as it keeps things sealed...