Where to drill torque tube hole on '51

[Kestrel]

I've seen threads referring to drilling and tapping a small hole in the torque tube to check for and to drain off any escaping ATF into rear end. My car's a '51 Buick Super with Dynaflow.

 

Could someone advise where is a good location for this hole and any other considerations in this effort ? I imagine somewhere aft of the E brake bracket ?

 

I don't like drilling holes in general and want to do it right the first time. Thanks !

 

[old-tank]

Just in front of the white paint.

[Kestrel]

Thanks Tank !

[Dennis Hagen]

I used a 1/8 pipe tap, screwed in a nipple with clear tube attached pointing up and can monitor level easily.

[Kestrel]

I like that idea. Then simply use a flashlight to check for any rising fluid ?

[Dennis Hagen]

On 9/19/2019 at 7:12 PM, Kestrel said:

I like that idea. Then simply use a flashlight to check for any rising fluid ?

Just bend it down to lower level.

[old-tank]

On 9/19/2019 at 3:44 PM, Dennis Hagen said:

I used a 1/8 pipe tap, screwed in a nipple with clear tube attached pointing up and can monitor level easily.

Good idea, but be advised that gear lube from the differential may show up if the pinion seal is defective.  If you find gear lube, just leave it since it will find a level below the driveshaft and is no problem.  If transmission fluid or a mixture, take action at the front of the torque tube.

[JohnD1956]

Is there a gasket between the torque tube and the rear axle?  If not, is a hole really necessary?  

[old-tank]

Gasket yes

Hole yes

[JohnD1956]

6 hours ago, old-tank said:

Gasket yes

One of the differences for 56 models.