Drill Drain Hole in Torque Tube for ATF?

[Guest 70 Electra]

In another recent posting, Old-Tank suggested drilling a small hole in the back of the torque tube, to allow any ATF (leaking from tranny) to "escape" without a) getting into rear end, or causing prop shaft problems.

This sounds like a great idea, with no apparent downside....so great, if fact, I've got to wonder why the factory never did it. I am considering it as a precautionary measure on my 60, even though I currently have no problems.

Have any of you other guys done this? Are there any un-forseen drawbacks to doing it?

[Guest BJM]

Greg,

We can only speculate why the factory did not do it however, it may have been due to not wanting dirt to get into a closed area. They probably felt the engineering behind the torque ball connection to the Dynaflow would not cause the service issues we see today.

I will probably drill the hole in my fixed tube as well on the 49 Roadmaster because I won't be driving it in 'dirty' conditions for extended periods so it's a different world from when these cars were just daily driven vehicles.

Jake

[old-tank]

I tap the hole and install a small screw to act as a plug. This will keep dirt/water out and if you do have a 'leaker' then you can drain it regularly instead of having a mess.

Willie

[Guest 70 Electra]

Willie,

Thanks. Putting in a plug is an even better idea than just the hole.

One last thing....How big a hole do you recommend? And how far forward from the back of the tube?

Thanks,

Greg

[old-tank]

Greg

On all 3 of my 55's the hole is just in front of the rear flange on the torque tube. I just looked at some parts and noted that if the hole is drilled 4.5" in front of the flange you can drill into the driveshaft to empty it if you suspect it to contain fluid.

I drill the hole to be tapped for a 3/16 bolt/screw.

Willie