V730 Dipstick Tube Air Vent??

[gus]

There is a 1/16" hole 1.5" from the top of my dipstick tube. Every time I go to add TF (Not very often) I forget about this hole and spill it until I remember to hold my finger over it!

Is this hole supposed to be there? It seems to be a big dirt collector to me since it is well below the dipstick rubber seal.

[TomC]

My V730 fill tube does not have that.  Wrap some electrical tape around it and see what happens.  The vent on the top of the transmission-the cap should be loose.  Good Luck, TomC

[luvrbus]

A 730 I worked on had a cotter pin with a chain in the hole what the chain was for I never figured it out so I welded the hole closed

[gus]

Thanks guys.

I wrapped it with Al tape because I had to do it anyway for a hose that was rubbing the dipstick tube. I'll leave it on and see what happens.

The chain was probably attacked to the dipstick or a cap, my PS reservoir has a chain attached to the dipstick like that.

[Chopper Scott]

My 740 has the same hole. I use a funnel that goes past the hole. I'm sure it is a vent. In fact I overfilled it once and going down the road it blew tranny oil out the hole! A nice little smoke show. LOL

[gus]

Chopper,

That is food for thought, but how do you know it wouldn't have blown fluid out around the dipstick or top vent anyway?

Running any AT overfilled is not good, bus or auto.

[Lin]

I think that the Allisons have an overfill relief on them anyway.

[gus]

So far my inclination is to leave it closed and see what happens. I'm departing on a 4000 mi trip next week so I'll see how it goes.

[Chopper Scott]

Just sharing my experience. Didn't think a quart overfull would matter. Have a great trip.